2. 3D Scene

The 3D Scene module is used for integrating video outputs (such as projectors), video inputs (such as cameras), screen surfaces and stage automation devices in a virtual representation of the real-world stage space. It is through manipulations of this virtual stage space (the 3D Scene) that operations such as camera calibration, screen surfaces tracking, projection calibration and blending will be made possible.

Tasks and operations described in this section of the manual mainly have to do with the binding between the real-world stage space and the virtual stage space as it is represented in PHOTON. Naturally, if you want to see actual results in the real world, Displays (such as video projectors or monitors) must be connected to the Video Output Ports, and you have to declare all of your project’s Virtual Video Outputs in the Settings module (see Section 1.6 Virtual Video Outputs Creation in Chapter 2 Setting Up a Show).

2.0.1 3D Scene Lexicon

Throughout this section of PHOTON’s technical documents the following terms are regularly used:

Display Displays are any kind of device used for displaying video signals, such as video projectors, video monitors, LED walls, etc.

Signal Transmission Signal transmission refers to the act of sending a video signal point-to-point from a Video Output Port (a graphic card’s physical output) to a device used for display, such as a video projector or monitor. Signal transmission is usually accomplished through cable distribution (fiber, HD-SDI, Ethernet, etc.).

Video Output Ports Video Output Ports are the physical connectors attached to the graphic cards that are installed in the servers used to output video signal.

Virtual Video Outputs PHOTON uses Virtual Video Outputs as a way to represent the Video Output Ports. Virtual Video Outputs have to be declared in the Outputs list located in the Photon tab of the Settings module window (see Section 1.6 Virtual Video Outputs Creation in Chapter 2 Setting Up a Show).

Virtual Displays Virtual Displays are the virtual counterparts of the tangible, real-world displays described in this lexicon. Some types of Virtual Displays, such as Projectors, can be automatically created when Virtual Video Outputs are first declared.

Screens PHOTON’s structure is based on real and virtual screens. All screens used as displays in the physical world have a virtual counterpart in the 3D Scene module, which acts as a simulation of the stage (or exhibition) space. Each real-world screen will have to be represented by a virtual one, which in turn will be linked to one or more video outputs. In the 3D Scene module, Screens act as a virtual representation of the Projection Surfaces. They are also represented in the Timeline module, where you can assign layers of media clips to them.

Video Content The term “video content” refers to the still images and video files that are imported into PHOTON, mapped as a texture onto Screens, and eventually played back using the Timeline module.

Calibration Calibration designates a process through which geometric coordinates are established between elements in the virtual scene and their real-world counterparts. By aligning the geometric features shared by a real screen surface and its model, PHOTON can reconstruct the position and orientation of displays as a means of mapping video content onto physical objects and other structural elements of the real-world stage. Many processes taking place during calibration are handled automatically by PHOTON. For example, edge blending between video outputs can be calculated dynamically in real time without user intervention. The system also automatically differentiates between cases where 2D or 3D transformations are applied, based on the geometric characteristics of the screen’s surface. PHOTON supports many approaches to calibration; some involve manual operations, and others are automated and rely on data provided via the analysis of camera feeds.

Blending Blending designates a process through which the projected images of multiple projectors are altered and seamlessly blend into one another, creating an uninterrupted surface (see Section 2.8 Blending in Chapter 4 Programming a Show).

2.1 Signal Routing and Display Identification

Before starting a calibration process, you should always validate signal paths and make sure the various video displays (monitors, projectors, etc.) are correctly identified. Beyond the obvious problems caused by broken signal paths, incorrect video output identification might lead to confusion during the calibration process.

Before activating Display Identification, make sure all of your Displays are powered and properly connected to the Video Output Ports on all servers. Also make sure you have declared all of your Virtual Video Outputs in the Settings module (see Section 1.6 Virtual Video Outputs Creation in Chapter 2 Setting Up a Show). Otherwise, PHOTON will not output video content.

2.1.1 Signal Routing

In order to send video content to a display, the following path must be followed:

  • Media > Screens > Virtual Display > Virtual Output > Graphic Card Physical Output > Signal Transmission > Display

If the signal does not reach the Display, you should test the signal path in the order described above.

2.1.2 Display Identification

PHOTON features an identification card system designed to simplify troubleshooting operations related to display identification and signal path continuity.

PHOTON can simultaneously generate random-colored identification cards featuring output names and corresponding display names for each declared Virtual Video Output. (Note that animated VYV logos and an output name are integrated in each identification card.)

Sending identification cards simultaneously through every output will allow you to visually validate the signal path and the output configuration (and naming).

Enable Display Ident

Before enabling Display Ident you should have integrated your Display Servers and Display Master Servers into your Server Group, and declared all of their Outputs in the Settings module (see Section 1.1.1 Server Group Creation in Chapter 2 Setting Up a Show and Section 1.6 Virtual Video Outputs Creation in Chapter 2 Setting Up a Show). Doing so will allow you to see the identification cards in your Displays.

  1. Open the File Manager module by pressing [Alt+C] or by selecting {System > 3D Scene}.

  2. Enable the Calibration mode by pressing [4] or by clicking on the [Calibration] toggle.

  3. Open the Settings Panel by clicking on the gear icon button.

  4. Click on the [Display Ident] toggle to activate Display Ident.

Identification cards will be rendered on top of everything, and will therefore hide calibration and display rendering. Make sure Display Ident is off when you are done with it.

2.2 Adding Projection Surfaces

Projection Surfaces need to be added in the 3D Scene in order to create Screens that will be made visible for Virtual Displays (see Section 2.5 Projection Surfaces Visibility in Chapter 2 Setting Up a Show). When Screens are paired with Virtual Displays they can be calibrated with their real-life counterparts. Screens will also co-exist in the Timeline module, where they hold layers of video content.

Projection Surfaces are virtual 3D objects that formally correspond to their real-life counterparts; they make it possible for a wall (onto which video content is projected) to be represented by a rectangular plane, or the surface of a planetarium to be represented by a hemisphere, etc.

PHOTON features a library of Default Objects from which you can pick and choose. This library contains commonly used Projection Surfaces (sphere, cube, rectangular plane, etc.). It is also possible to import custom-made 3D objects in PHOTON in order to represent complex Projection Surfaces such as theatrical props and set elements (see Section 2.1 Import 3D Objects in Chapter 3 Importing Content).

Add a Projection Surface

  1. Open the File Manager module by pressing [Alt+C] or by selecting {System > 3D Scene}.

  2. Enable the Modeling mode by pressing [1] or by clicking on the [Modeling] toggle.

  3. Select a Default Object through {Primitive > Default Objects > one of the objects listed in the Default Objects library} or a custom 3D model through {Primitive > XSI or OBJ or FBX}.

Once selected, the new Projection Surface will appear in the 3D Scene as an entry in the Scene Primitives list. It will also appear in the 3D Scene Preview.

2.3 Manual 2D Keystone Calibration

Once signal paths have been tested and Displays properly identified (see Section 2.1 Signal Routing and Display Identification in Chapter 2 Setting Up a Show), it is time to calibrate outputs.

Manual 2D keystone calibration is the simplest form of calibration offered in PHOTON. It should be used in cases where video content is projected onto flat surfaces or displayed on video monitors. By manipulating the four corners of a Screen within a Virtual Display, the user can position them in relation to the four corners of a Display (corner-pin). This method can also be used to correct the trapezoidal distortion of an image caused by a difference in angle between the alignment of a real-world projector and projection surface (keystone correction).

2.3.1 Add a Projector in the 3D Scene

In order to start the calibration process, you will need a virtual representation of the real-world display. If you are attempting a manual keystone calibration, the appropriate Virtual Display type is a Projector (even if you are attempting to calibrate a video monitor such as a TV).

Make sure the Virtual Video Output that corresponds to the Video Output Port was declared in the Settings module when you created your project’s Network Group. If this wasn’t done, please do so before continuing (see Section 1.6 Virtual Video Outputs Creation in Chapter 2 Setting Up a Show).

Automatic Projector Creation

When a Virtual Video Output is declared in the Settings module, a confirmation box opens and displays the following message: “Do you want to create a Projector in the 3D Scene and link it to this output?” By clicking the [Yes] button you will automatically add a Projector in the 3D Scene linked to the new output.

Keyboard Calibration Point Manipulations

Manual Projector Creation

If for any reason you created a Virtual Video Output but did not assign a Projector to it, you will have to follow these steps:

  1. In the 3D Scene module, select {Primitive > Display > Projector} to create a new Projector. A new entry (named Projector) will appear in the Scene Primitives list. A pyramid, representing the light beam emitted by the Projector, will also be visible in the 3D Scene Preview.(see img 1)

  2. In the Settings module, go to the Photon Selection list and select the server you want to use as an output for the video signal.

  3. Beside each of the Virtual Video Outputs you created, you will find a dropdown menu with the {no output} option selected. Using the dropdown menu linked to the appropriate Virtual Video Output, select the Projector you created. (see img 2)

img 1
img 2

Renaming a Projector

Once a Projector in the 3D Scene is linked to a Virtual Video Output, you can rename it to make it easier to identify. (In complex projects involving many Displays, renaming Projectors is a must-do.)

  • [Double-click] on the Projector’s entry in the Scene Primitives list. A text field will appear allowing you to enter a new name for the Projector.

2.3.2 Add a Plane in the 3D Scene

For a manual 2D calibration the Projection Surface is necessarily a plane. This plane can represent a video monitor (a TV screen, for example) or a wall upon which video content will be projected.

  • To add a plane to the 3D Scene, select {Primitive > Default Objects > Plane} in the Primitive dropdown menu.

The plane will appear in the Scene Primitives list, and a visual representation of it will appear at the origin (0,0,0) of the 3D Scene Preview.

Many ready-to-use 3D objects are available in PHOTON. They can act as Projection Surfaces and simplify the construction of the virtual representation of your real-world stage space. 3D objects can be selected from the Primitive dropdown menu {Primitive > Default Objects}.

2.3.3 Scale, Translate and Rotate the Plane

It is possible to modify the shape of the plane in order to match the ratio of the real-world display it represents. You can also position and rotate the plane in space to match the position and orientation of the real-world display.

Why Apply 3D Transformations?

Scaling, positioning and orienting are crucial in stage contexts where many real-world projectors cover many Screen Surfaces. Under these circumstances, it is important to accurately represent the spatial relations between all objects in PHOTON’s virtual world. If the spatial relations between objects aren’t accurately represented it won’t be possible to complete the calibration process.

Scaling, positioning and orienting are not crucial in stage contexts involving single Displays linked to single Screen Surfaces that act as autonomous pairs. However, doing so is considered a best practice and will give you access to a realistic pre-visualization of the project.

Project pre-visualization is one of PHOTON’s key features. VYV’s software can create full 3D simulations of the real-world stage space. In the 3D Scene module Screen Surfaces (with their video content), Displays, cameras, lighting equipment, and set elements can be placed in a virtual space that provides a complete overview of a project.

Applying the 3D Transformations

An object’s size, position or orientation (Decorative Objects as well as Projection Surfaces) in the 3D Scene can be modified using the Transformations Panel or Transformation Manipulators.

Transformations Panel

The Transformations Panel contains multiple sliders that allow the modification of the Scale, Translate and Rotate parameters for each axis (X, Y and Z) for any object previously created in the 3D Scene module.

  • Select the object you want to alter by clicking on its entry in the Scene Primitives list.

  • To open the Transformations Panel, press [T] on the keyboard or select {Window > Transformation} in the 3D Scene’s main menu.

  • To change the geometric coordinates of an object, adjust the value of the sliders. You can adjust the value of a slider by manipulating it with a [Click+Drag], or you can [Double-click] on it to open a text field where you can enter a desired numeric value.

The effects of these transformations can be seen in the 3D Scene Preview. The graphic representation of the selected object will be modified as well.

Slider values differ depending on the parameters they represent. The Scale sliders are not dimension sliders; they act as scaling coefficients applied to the object’s original size. For example, if the scale value of a cube featuring edges of 2 meters is changed from 1 to 4 on all three axes, the cube will now have edges of 8 meters. The Translate sliders express a value in meters. The Rotate sliders express values in angles. And the Rotate Axis sliders are used to apply a rotation expressed in an angle that corresponds to specific vectors. For example, an angle is set with the first slider while the three other sliders represent vector values for each axis that will determine how the rotation will be applied to each.

Transformation Manipulators

The Transformation Manipulators facilitate direct modification of a 3D object’s parameters —Scale, Translate, Rotate — by manipulating your mouse in the 3D Scene Preview.

Enable the desired Transformations Manipulator using the following methods:

  • Scale Manipulator: Press [X] on the keyboard or click on the Scale button located in the top-right corner of the 3D Scene window.

  • Translate Manipulator: Press [V] on the keyboard or click on the Translate button located in the top-right corner of the 3D Scene window.

  • Rotate Manipulator: Press [C] on the keyboard or click on the Rotate button located in the top-right corner of the 3D Scene window.

The Transformation Manipulators will appear when a 3D object is selected.

PHOTON’s Manipulators feature a standard color-scheme for its 3D coordinate system: X is red, Y is green and Z is blue.

  • [Click+Drag] the handle of the axis parameter you want to modify (X, Y or Z). The handle will become yellow when selected.

  • The Scale and Translate Manipulators feature a yellow dot at the intersection of their axes. [Click+Drag] the yellow dot to simultaneously apply transformations to all axes.

Enabling a Manipulator will disable camera movements in the 3D Scene Preview. To switch back to camera control, press [S] on the keyboard or click the Camera button located at the top-right corner of the 3D Scene.

If you want to control the camera while a Manipulator is enabled, press and hold [S] on the keyboard. This will allow you to manipulate the camera. To switch back to Manipulator control, release the [S] key.

2.3.4 Freeze Transformations

Freezing an object’s Transformations sets its current size, orientation and location as the new default values without modifying the object’s geometric coordinates.

Freeze an Object

  • Select the object by clicking on its entry in the Scene Primitives list.

  • To activate the Transformations Panel press [T] on the keyboard or select {Window > Transformation} in the 3D Scene main menu.

  • Click on the [Set Freeze] button located at the top of the Transformations Panel.

  • If you want to revert to the object’s initial parameters, you can unfreeze it by clicking on the [Reset Freeze] button located at the top of the Transformations Panel.

Why Freeze?

Freezing an object sets its Calibration Points directly in relation to its new position in the 3D Scene Preview. Calibration Points are created out of a 3D object’s vertices and are the main features used during the calibration process. Therefore, it is crucial to alert the software through the [Set Freeze] command if a 3D object’s geometric parameters have been modified before starting the calibration process.

Furthermore, 3D objects in PHOTON can be linked to position and orientation data (provided by stage automation and tracking or animations). These 3D objects will move in the real world but you will want to retain their original geometric data for the purposes of display calibration. Freezing makes this possible, and facilitates accurate projection on surfaces that move.

2.3.5 Map the Plane to the Display

Once the plane that acts as the Projection Surface has undergone the appropriate geometric transformations and has been frozen, you have to add it to the Objects Reference list.

In order to calibrate a Display (find its position and orientation in the real world), PHOTON has to build geometric correspondences with at least one 3D object representing a physical structure in the real world. In this case, the plane will act both as a Projection Surface and a Reference Object.

  1. Select the 3D Scene module’s Calibration mode by pressing [4] or by clicking on the [Calibration] button located at the top-right corner of the 3D Scene window. Once the Calibration mode is enabled, the 3D Scene Preview will turn red and the Calibration Tools Window will open in the lower right part of the 3D Scene window.

  2. Select the Display you want to calibrate by clicking on its entry in the Calibration Tools Window list. (If you haven’t renamed the Display, it will be listed as “Projector.”) Make sure the Display Grid is enabled. By showing a representation of how the Display’s texture map is distributed (both in the 3D Scene Preview and in the real-world projection) the Display Grid will let you preview the amount of distortion affecting the projected image. Normally, you will try to limit distortion as much as possible by manipulating the Calibration Points.

  3. Press [D] or click on the gear icon button to access the 3D Scene module’s Settings menu and click on the [Display Grid] toggle if the Display Grid isn’t already activated.

  4. In the Primitive Preset window section (below the Calibration Tools Window), select the plane from the {Object Reference} dropdown menu.

  5. Click on the [Add] button to add the plane as a Reference Object. Also, notice that the plane was automatically added to the Objects Visibility list (see Section 2.5 Projection Surfaces Visibility in Chapter 2 Setting Up a Show).

The plane will be covered by green dots corresponding to its vertices in the 3D Scene Preview.

You will notice that a single item named “Manual” initially populates the Objects Reference list. Adding a new object as the plane to the Objects Reference list eliminates the item named “Manual.” The “Manual” item refers to the fact that if a Display does not have a Reference Object, it can still be positioned and oriented manually using your mouse in the Calibration Tools Window Preview. Hover the mouse on the preview and use the mouse scroll wheel for positioning on the Z-axis, Right-click+Drag for positioning on the X- and Y-axes, and Left-click+Drag to orient the Display.

Multiple 3D objects can be added as Reference Objects for the same Display. This allows the Display to simultaneously support multiple calibrations. For example, in a case where a single video projector covers two different Screen Surfaces, each Screen Surface would be represented by a 3D object, and both 3D objects would have to be added as Reference Objects to the same Display (representing the video projector).

A single 3D object can be added as a Reference Object for multiple Displays. For example, in a situation where beams of light from multiple projectors fall on a single Projection Surface, the same 3D object (corresponding to the Projection Surface) would have to be added to each of the Displays (corresponding to the video projectors).

2.3.6 Calibration Point Creation and Manipulation

In order to calibrate the Display, you will have to create four Calibration Points that match the four corners of the plane. You will then manipulate these Calibration Points until the image being displayed isn’t distorted.

Calibration Point Creation

Calibrations Points are created by converting vertices: the green dots that correspond to the 3D object’s vertices. This is done through a [Ctrl+Double-click] applied to a vertex.

To perform a manual 2D keystone calibration, you will have to create Calibration Points using the four corners of the plane.

  • [Ctrl+Double-click] sequentially on the four vertices that match the four corners of the plane.

Whenever a vertex point is converted to a Calibration Point and is selected, it will double in size and turn white. An unselected Calibration Point will retain this double size but will turn blue.

Once the four Calibration Points have been created, the plane displayed in the Calibration Tools Window will snap to its four corners and completely fill its space.

If you want to use the full pixel space offered by the Display and there isn’t a need for any kind of geometric correction (if you plan to output the signal to a video monitor, for example), you are done.

Calibration Points, Crosses and Lines

Whenever a Calibration Point is created, a green cross will appear in the Calibration Tools Window Preview where it is positioned. The green cross will also be projected by the Display it is linked to. If the Calibration Point is moved, the cross will also move to reflect the change of position.

If the Calibration Point is selected, its corresponding green cross will feature elongated white lines that will extend until they reach the edge of the projected image.

These two features — green crosses and white lines — should help you calibrate the Display. Parameters for both the crosses and the lines are accessible in the Options menu. If you want to modify these parameters, click on the gear icon button to access the Options Panel and manipulate the following widgets:

  • Display Cross toggle: [Click] on the toggle to show/hide the green crosses.

  • Display Lines toggle: [Click] on the toggle to show/hide the white lines.

  • 2D Point Size slider: [Click+Drag] the slider to change the size of the green crosses.

  • Line Width slider: [Click+Drag] the slider to change the width of the white lines.

Manipulating Calibration Points

If you have to apply 2D geometric corrections (such as keystoning) to the video output, you will have to manipulate the Calibration Points. By moving Calibration Points in PHOTON you will alter the projected image’s geometric coordinates and compensate for alignment differences between a Projector and its related Projection Surface.

Calibration Points will have to be selected and moved one by one from those that were previously declared. This step has to be repeated with each of the previously declared Calibration Points (a keystone correction will involve four Calibration Points). The final positions of the Calibration Points in the projected image (on the real-world Projection Surface) will make it possible to project an accurate (geometrically correct) image.

Calibration Points can be manipulated by using the keyboard on it’s own, or by using a combination of the mouse and keyboard.

Select Previous/Next Calibration Point

[Page Up]

selects the next Calibration Point

selects the next Calibration Point

selects the previous Calibration Point

Move the Calibration Point that is Currently Selected

[Arrows]

move the selected Calibration Point in any of the four directions represented by the arrows keys

[Shift+Arrows]

applies the same effect as above, only 10 times slower

[Ctrl+Shift+Arrows]

applies the same effect as above, only 100 times slower

Move the Entire Calibration

[Alt+Arrows]

moves all of the Calibration Points at the same time

[Alt+Shift+Arrows]

applies the same effect as above, only 10 times slower

Add/Remove a Calibration Point

[-]

removes the Calibration Point that is currently selected

[+]

removes the Calibration Point that is currently selected.

Mouse and Keyboard Calibration Point Manipulations

Select a Calibration Point from the Calibration Tools Window Preview

[Ctrl+Left-click]

selects the Calibration Point that is closest to your cursor and moves it to where you have clicked

Select a Calibration Point in the 3D Scene Preview

[Ctrl+Left-click]

on a Calibration Point (blue dots) to select it (it will turn white)

Cycle Through Calibration Point Selection

[Mouse wheel]

Place the mouse over the Calibration Tools Window Preview and use the mouse wheel to cycle through the previously declared Calibration Points

Move a Calibration Point

[Left-click]

anywhere in the Calibration Tools Window Preview to move the selected Calibration Point to its new location

Left-click+Drag]

anywhere in the Calibration Tools Window Preview to move the selected Calibration Point in the direction that you drag the mouse

[Shift+Left-click+Drag]

applies the same effect as above, only 10 times slower

Add/Remove a Calibration Point

[Ctrl+Double-click]

on a vertex (green dots) on the Reference Object in the 3D Scene Preview to create a new Calibration Point

[Ctrl+Right-click]

on a Calibration Point to remove it

2.4 Manual 3D Calibration

The manual calibration process for a 3D projection surface (for example, a cube) is only slightly different from the one described in section 2.3 Manual 2D Keystone Calibration. The main difference resides in the number of Calibration Points needed by PHOTON to achieve a geometric match between the real-world projector and projection surface with their virtual counterparts. If a 3D object is selected for calibration and a sufficient quantity of well-distributed Calibration Points are identified on its surface (with regard to width, height and depth), PHOTON will automatically perform a 3D calibration. There is no need to specify if a calibration is tridimensional or bidimensional.

  • A minimum of six Calibration Points will be needed to calibrate a projector for a 3D object. These Calibration Points correspond to some of the vertices of the 3D object acting as the Projection Surface.

The vertices selected for the calibration should be distributed along the 3D object’s three axes (X, Y and Z) in order to convey enough information about its volume and surface to PHOTON. For example, selecting all of the Calibration Points on the same surface of a 3D object will prevent the software from performing tridimensional calibration since coplanar vertices do not carry information about the 3D object’s volume.

  • A maximum of nine Calibration Points should be used when calibrating a 3D object. Using more Calibration Points is possible, but it might lead to an accumulation of small positioning errors, which will have a detrimental effect on the calibration.

2.4.1 Add a Projector in the 3D Scene

In order to start the calibration process, you will need a virtual representation of the real-world display. If you are attempting a manual 3D calibration, the appropriate Virtual Display type is a Projector.

Make sure the Virtual Video Output that corresponds to the Video Output Port was declared in the Settings module when you created your project’s Network Group. If this wasn’t done, please do so before continuing (see Section 1.6 Virtual Video Outputs Creation in Chapter 2 Setting Up a Show).

Automatic Projector Creation

When a Virtual Video Output is declared in the Settings module, a confirmation box opens and displays the following message: “Do you want to create a Projector in the 3D Scene and link it to this output?” By clicking the [Yes] button you will automatically add a Projector in the 3D Scene linked to the new output.

Manual Projector Creation

If for any reason you created a Virtual Video Output but did not assign a Projector to it, you will have to follow these steps:

  • In the 3D Scene module, select {Primitive > Display > Projector} to create a new Projector. A new entry (named Projector) will appear in the Scene Primitives list. A pyramid, representing the light beam emitted by the Projector, will also be visible in the 3D Scene Preview.

  • In the Settings module, go to the Photon Selection list and select the server you want to use as an output for the video signal.

  • Beside each of the Virtual Video Outputs you created, you will find a dropdown menu with the {no output} option selected. Using the dropdown menu linked to the appropriate Virtual Video Output, select the Projector you created.

Renaming a Projector

Once a Projector in the 3D Scene is linked to a Virtual Video Output, you can rename it to make it easier to identify. (In complex projects involving many Displays, renaming Projectors is a must-do.)

  • Double-click on the Projector’s entry in the Scene Primitives list. A text field will appear allowing you to enter a new name for the Projector.

2.4.2 Add a 3D Object in the 3D Scene

For a manual 3D calibration the Projection Surface is necessarily a 3D object. This 3D object can represent a prop or the surface of a tridimensional set element onto which video will be projected. The 3D object can either be selected from the ready-made Default Objects in the Primitive dropdown menu or it can be a custom made model (.obj, .fbx or .xsi) imported through the File Manager module. The following subsections will use the cube corner model (listed as a {Cube}) from the Default Objects as an example.

  • To add a 3D object to the 3D Scene, select {Primitive > Default Objects > Cube} in the Primitive dropdown menu.

The cube corner will appear in the Scene Primitives list, and a visual representation of it will appear at the origin (0,0,0) of the 3D Scene Preview.

Many ready-to-use 3D objects are available in PHOTON. They can act as Projection Surfaces and simplify the construction of the virtual representation of your real-world stage space. 3D objects can be selected from the Primitive dropdown menu {Primitive > Default Objects}.

2.4.3 Scale, Translate and Rotate the 3D Object

It is possible to modify the shape of the cube corner in order to match the ratio of the real-world prop it represents. You can also position and rotate the cube corner in space to match the position and orientation of the real-world prop.

Why Apply 3D Transformations?

Scaling, positioning and orienting are crucial in stage contexts where many real-world projectors cover many Screen Surfaces. Under these circumstances, it is important to accurately represent the spatial relations between all objects in PHOTON’s virtual world. If the spatial relations between objects aren’t accurately represented it won’t be possible to complete the calibration process.

Scaling, positioning and orienting are not crucial in stage contexts involving single Displays linked to single Screen Surfaces that act as autonomous pairs. However, doing so is considered a best practice and will give you access to a realistic pre-visualization of the project.

Project pre-visualization is one of PHOTON’s key features. VYV’s software can create full 3D simulations of the real-world stage space. In the 3D Scene module Screen Surfaces (with their video content), Displays, cameras, lighting equipment, and set elements can be placed in a virtual space that provides a complete overview of a project.

Applying 3D Transformations

An object’s size, position or orientation (Decorative Objects as well as Projection Surfaces) in the 3D Scene can be modified using the Transformations Panel or Transformation Manipulators.

Transformations Panel

The Transformations Panel contains multiple sliders that allow the modification of the Scale, Translate and Rotate parameters for each axis (X, Y and Z) for any object previously created in the 3D Scene module.

  • Select the object you want to alter by clicking on its entry in the Scene Primitives list.

  • To open the Transformations Panel, press [T] on the keyboard or select {Window > Transformation} in the 3D Scene’s main menu.

  • To change the geometric coordinates of an object, adjust the value of the sliders. You can adjust the value of a slider by manipulating it with a [Click+Drag], or you can [Double-click] on it to open a text field where you can enter a desired numeric value.

The effects of these transformations can be seen in the 3D Scene Preview. The graphic representation of the selected object will be modified as well.

Slider values differ depending on the parameters they represent. The Scale sliders are not dimension sliders; they act as scaling coefficients applied to the object’s original size. For example, if the scale value of a cube featuring edges of 2 meters is changed from 1 to 4 on all three axes, the cube will now have edges of 8 meters. The Translate sliders express a value in meters. The Rotate sliders express values in angles. And the Rotate Axis sliders are used to apply a rotation expressed in an angle that corresponds to specific vectors. For example, an angle is set with the first slider while the three other sliders represent vector values for each axis that will determine how the rotation will be applied to each.

Transformation Manipulators

The Transformation Manipulators facilitate direct modification of a 3D object’s parameters —Scale, Translate, Rotate — by manipulating your mouse in the 3D Scene Preview.

Enable the desired Transformations Manipulator using the following methods:

  • Scale Manipulator: Press [X] on the keyboard or click on the Scale button located in the top-right corner of the 3D Scene window.

  • Translate Manipulator: Press [V] on the keyboard or click on the Translate button located in the top-right corner of the 3D Scene window.

  • Rotate Manipulator: Press [C] on the keyboard or click on the Rotate button located in the top-right corner of the 3D Scene window.

The Transformation Manipulators will appear when a 3D object is selected.

PHOTON’s Manipulators feature a standard color-scheme for its 3D coordinate system: X is red, Y is green and Z is blue.

  • [Click+Drag] the handle of the axis parameter you want to modify (X, Y or Z). The handle will become yellow when selected.

  • The Scale and Translate Manipulators feature a yellow dot at the intersection of their axes. [Click+Drag] the yellow dot to simultaneously apply transformations to all axes.

Enabling a Manipulator will disable camera movements in the 3D Scene Preview. To switch back to camera control, press [S] on the keyboard or click the Camera button located at the top-right corner of the 3D Scene.

If you want to control the camera while a Manipulator is enabled, press and hold [S] on the keyboard. This will allow you to manipulate the camera. To switch back to Manipulator control, release the [S] key.

2.4.4 Freeze Transformations

Freezing an object’s Transformations sets its current size, orientation and location as the new default values without modifying the object’s geometric coordinates.

Freeze an Object

  • Select the object by clicking on its entry in the Scene Primitives list.

  • To activate the Transformations Panel press [T] on the keyboard or select {Window > Transformation} in the 3D Scene main menu.

  • Click on the [Set Freeze] button located at the top of the Transformations Panel.

  • If you want to revert to the object’s initial parameters, you can unfreeze it by clicking on the [Reset Freeze] button located at the top of the Transformations Panel.

Why Freeze?

Freezing an object sets its Calibration Points directly in relation to its new position in the 3D Scene Preview. Calibration Points are created out of a 3D object’s vertices and are the main features used during the calibration process. Therefore, it is crucial to alert the software through the [Set Freeze] command if a 3D object’s geometric parameters have been modified before starting the calibration process.

Furthermore, 3D objects in PHOTON can be linked to position and orientation data (provided by stage automation and tracking or animations). These 3D objects will move in the real world but you will want to retain their original geometric data for the purposes of display calibration. Freezing makes this possible, and facilitates accurate projection on surfaces that move.

2.4.5 Map the 3D Object to the Display

Once the cube corner that acts as the Projection Surface has undergone the appropriate geometric transformations and has been frozen, you have to add it to the Objects Reference list.

In order to calibrate a Display (find its position and orientation in the real world), PHOTON has to build geometric correspondences with at least one 3D object representing a physical structure in the real world. In this case, the cube corner will act both as a Projection Surface and a Reference Object.

  1. Select the 3D Scene module’s Calibration mode by pressing [4] or by clicking on the [Calibration] button located at the top-right corner of the 3D Scene window. Once the Calibration mode is enabled, the 3D Scene Preview will turn red and the Calibration Tools Window will open in the lower right part of the 3D Scene window (see img1).

  2. Select the Display you want to calibrate by clicking on its entry in the Calibration Tools Window list. (If you haven’t renamed the Display, it will be listed as “Projector.”) Make sure the Display Grid is enabled. By showing a representation of how the Display’s texture map is distributed (both in the 3D Scene Preview and in the real-world projection) the Display Grid will let you preview the amount of distortion affecting the projected image. Normally, you will try to limit distortion as much as possible by manipulating the Calibration Points.

  3. Press [D] or click on the gear icon button to access the 3D Scene module’s Settings menu and click on the [Display Grid] toggle if the Display Grid isn’t already activate (see img2).

  4. In the Primitive Preset window section (below the Calibration Tools Window), select the {Cube} (which is in fact a cube corner) from the {Object Reference} dropdown menu.(see img 3)

  5. Click on the [Add] button to add the cube corner as a Reference Object. Also, notice that the cube corner was automatically added to the Objects Visibility list (see Section 2.5 Projection Surfaces Visibility in Chapter 2 Setting Up a Show) (see img 4)

img 1
img 2
img 3

img 4

The cube corner will be covered by green dots corresponding to its vertices in the 3D Scene Preview.

You will notice that a single item named “Manual” initially populates the Objects Reference list. Adding a new object as the cube corner to the Objects Reference list eliminates the item named “Manual.” The “Manual” item refers to the fact that if a Display does not have a Reference Object, it can still be positioned and oriented manually using your mouse in the Calibration Tools Window Preview. Hover the mouse on the preview and use the mouse scroll wheel for positioning on the Z-axis; [Right-click+Drag] for positioning on the X- and Y-axes; and [Left-click+Drag] to orient the Display.

Multiple 3D objects can be added as Reference Objects for the same Display. This allows the Display to simultaneously support multiple calibrations. For example, in a case where a single video projector covers two different Screen Surfaces, both Screen Surfaces would be represented by its own 3D object, and both 3D objects would have to be added as Reference Objects to the same Display (representing the video projector).

A single 3D object can be added as a Reference Object for multiple Displays. For example, in a situation where beams of light from multiple projectors fall on a single Projection Surface, the same 3D object (corresponding to the Projection Surface) would have to be added to each of the Displays (corresponding to the video projectors).

2.4.6 Calibration Point Creation and Manipulation

In order to calibrate the Display, you will have to create seven Calibration Points that match the corners of the cube corner. You will then manipulate these Calibration Points until the image being displayed isn’t distorted. (You can use the corner created by the junction of two straight walls and a floor to simulate an open cube if you don’t have access to such a prop.)

Calibration Point Creation

Calibrations Points are created by converting vertices: the green dots that correspond to the 3D object’s vertices. This is done through a [Ctrl+Double-click] applied to a vertex.

To perform a manual 3D calibration, you will have to create Calibration Points using the seven corners of the cube corner.

  • [Ctrl+Double-click] sequentially on the seven vertices that match the seven corners of the cube corner.

Whenever a vertex point is converted to a Calibration Point and is selected, it will double in size and turn white. An unselected Calibration Point will retain this doubling of size but will turn blue.

When you create a Calibration Point, move it to its new position before creating another one. Follow the remaining instructions to learn how to manipulate the Calibration Points.

Calibration Points, Crosses and Lines

Whenever a Calibration Point is created, a green cross will appear in the Calibration Tools Window Preview where it is positioned. The green cross will also be projected by the Display it is linked to. If the Calibration Point is moved, the cross will also move to reflect the change of position.

If the Calibration Point is selected, its corresponding green cross will feature elongated white lines that will extend until they reach the edge of the projected image.

These two features — green crosses and white lines — should help you calibrate the Display. Parameters for both the crosses and the lines are accessible in the Options menu. If you want to modify these parameters, click on the gear icon button to access the Options Panel and manipulate the following widgets:

  • Display Cross toggle: Click on the toggle to show/hide the green crosses.

  • Display Lines toggle: Click on the toggle to show/hide the white lines.

  • 2D Point Size slider: [Click+Drag] the slider to change the size of the green crosses.

  • Line Width slider: [Click+Drag] the slider to change the width of the white lines.

Manipulating Calibration Points

If you have to apply 3D geometric corrections to the video output, you will have to manipulate the Calibration Points. By moving Calibration Points in PHOTON you will alter the projected image’s geometric coordinates and compensate for alignment differences between a Projector and its corresponding Projection Surface.

Calibration Points will have to be selected and moved one by one. This step has to be repeated with each of the declared Calibration Points. The final positions of the Calibration Points in the projected image (on the real-world Projection Surface) will make it possible to project an accurate (geometrically correct) image.

Calibration Points can be manipulated by using the keyboard on it’s own, or by using a combination of the mouse and keyboard.

Keyboard Calibration Point Manipulations

Select Previous/Next Calibration Point

[Page Up]

selects the next Calibration Point

[Page Down]

selects the previous Calibration Point

Move the Calibration Point that is Currently Selected

[Arrows]

move the selected Calibration Point in any of the four directions represented by the arrows keys

[Shift+Arrows]

applies the same effect as above, only 10 times slower

[Ctrl+Shift+Arrows]

applies the same effect as above, only 100 times slower

Add/Remove a Calibration Point

[-]

removes the Calibration Point that is currently selected

[+]

adds a new Calibration Point corresponding to the vertex that is currently selected, or re-adds a previously deleted Calibration Point

Mouse and Keyboard Calibration Point Manipulations

Select a Calibration Point from the Calibration Tools Window Preview

[Ctrl+Left-click]

selects the Calibration Point that is closest to your cursor and moves it to where you have clicked.

Select a Calibration Point in the 3D Scene Preview

[Ctrl+Left-click]

on a Calibration Point (blue dots) to select it (it will turn white)

Cycle Through Calibration Point Selection

[Mouse wheel]

Place the mouse over the Calibration Tools Window Preview and use the mouse wheel to cycle through the previously declared Calibration Points.

Move a Calibration Point

[Left-click]

anywhere in the Calibration Tools Window Preview to move the selected Calibration Point to its new location

[Left-click+Drag]

anywhere in the Calibration Tools Window Preview to move the selected Calibration Point in the direction that you drag the mouse

[Shift+Left-click+Drag]

applies the same effect as above, only 10 times slower

Add/Remove a Calibration Point

[Ctrl+Double-click]

on a vertex (green dots) on the Reference Object in the 3D Scene Preview to create a new Calibration Point.

[Ctrl+Right-click]

on a Calibration Point to remove it

2.5 Projection Surfaces Visibility

Projection Surfaces have to be made visible for specific Displays in the 3D Scene before video content can be projected onto them.

A 3D object that was not made visible to a Display will still exist in the 3D Scene and the Timeline but will not have the ability to display content and will not act as a Projection Surface. Also, a 3D object can be made visible for some Displays while remaining invisible to others, therefore acting as a Projection Surface for specific video projectors.

Controlling the visibility of a 3D object for individual Displays is useful in contexts where multiple video projectors and screens coexist in the same space. Assigning the visibility of a Screen to specific Displays will ensure that the projected video content will not appear on other unintended surfaces. Also, specifying which Display sees which Screen helps a lot when optimizing a project — eliminating unnecessary Screens from the Visibility lists of selected Displays reduces the load on the servers. In some cases, 3D objects can be used to calibrate Displays but will not be used as Projection Surfaces.

The calibration processes described in sections 2.3 Manual 2D Keystone Calibration and 2.4 Manual 3D Calibration both feature a single 3D object mapped to a Display. When the 3D objects were added to the Objects Reference list, they were also automatically added to the Objects Visibility list.

Adding a Projection Surface to the Objects Visibility List

If a 3D object is added to the Objects Reference list (see Section 2.3.5 Map the Plane to the Display in Chapter 2 Setting Up a Show), it will automatically appear in the Objects Visibility list because this behavior covers the most common set up (a 3D object corresponding to a Screen is calibrated and will show video content).

If you want to manually add a Projection Surface to the Objects Visibility list, follow these steps:

  1. Make sure the 3D Scene module is open (by pressing [Alt+C] or by selecting {System > 3D Scene} from the Main menu) and that it is currently set in the Calibration mode (by pressing [4] or by clicking on the [Calibration] button).

  2. You should have already created the Display (see Section 2.3.1 Add a Projector in the 3D Scene in Chapter 2 Setting Up a Show) and the 3D object that will act as the Projection Surface (see Section 2.4.1 Add a Plane in the 3D Scene).

  3. Select the Display for which you want to make the Projection Surface visible by clicking on its entry in the Calibration Tools Window list.

  4. Select the 3D object corresponding to the Projection Surface you want to make visible for the currently selected Display from the dropdown menu located in the Objects Visibility window section.

Removing a Projection Surface from the Objects Visibility List

Follow these steps if you want to remove a 3D object previously declared as a Projection Surface from a Display’s Objects Visibility list:

  1. Make sure the 3D Scene module is open (by pressing [Alt+C] or by selecting {System > 3D Scene} from the Main menu) and that it is currently set in the Calibration mode (by pressing [4] or by clicking on the [Calibration] button).

  2. Select the Display for which you want to make the Projection Surface invisible by clicking on its entry in the Calibration Tools Window list.

  3. Use your mouse to rollover the Projection Surface’s entry in the Objects Visibility list and click on the “X” symbol to remove it.

Blanking a Projection Surface from the Objects Visibility List

You might want to temporarily remove a Projection Surface entry from the Objects Visibility list without permanently deleting it. This is called “blanking” and is akin to temporarily muting a video channel linked to a Display and a Projection Surface.

  1. Make sure the 3D Scene module is open (by pressing [Alt+C] or by selecting {System > 3D Scene} from the Main menu) and that it is currently set in the Calibration mode (by pressing [4] or by clicking on the [Calibration] button).

  2. Select the Display for which you want to make the Projection Surface invisible by clicking on its entry in the Calibration Tools Window list.

  3. Click on the [b] button next to the Projection Surface’s entry in the Objects Visibility list you want to blank. If you wish to “unblank” the Projection Surface, click on the “no entry” symbol that replaced the [b] button.

2.6 Convergence and Seamless Projection

The calibration processes described in sections 2.3 Manual 2D Keystone Calibration and 2.4 Manual 3D Calibration involved a single Display and a single Projection Surface functioning as an autonomous pair. However, in many situations, multiple projectors will aim at the same Projection Surface. This might be done to create seamless video coverage over the surface of a large screen or over a surface that wraps around a tridimensional structure. Multiple video projectors can also be stacked and aimed at the same screen to increase its luminosity. Both cases imply small changes to the calibration procedures and are explained below.

2.6.1 Convergence

Convergence occurs when multiple projectors are stacked and are aiming at the same Projection Surface. Convergent calibrations can be tricky to achieve because the projected image will be blurred if the geometrical corrections applied to each Display are not perfect.

To successfully apply a convergent calibration, make sure to follow these guidelines:

  • Use the same 3D object as the Reference Object for all Displays (in this case, the video projectors aimed at the same surface).

  • The 3D object acting as a Screen should also be made visible for each of the Displays.

  • Displays should share Calibration Points. Sharing some of the same Calibration Points will ensure that the Displays are properly aligned. The two most common examples are:

  • In a situation where two video projectors are aimed at the same area on a wall, the same four Calibration Points corresponding to the Screen’s four corners should be used for both Displays.

  • In a situation where two video projectors are aimed at a tridimensional structure acting as a Screen, Calibration Points placed in the intersection of the video projectors’ beams should be shared by both Displays.

  • Press [D] on the keyboard or click on the gear icon button to access the 3D Scene module’s Settings menu and click on the [Display Grid] toggle if the Display Grid isn’t already activated. Once activated, the Display Grid will help you align Displays because the pattern it projects onto Screens exaggerates the blurriness generated by a bad calibration.

2.6.2 Seamless Projection

In stage productions that rely on video mapping, coverage is often intended to span seamlessly across large surfaces. In some cases, large surfaces call for a very high pixel count, which can only be achieved by using multiple video projectors. To create the illusion of a seamless video image on a large surface follow these guidelines:

  • Video projector beams should cover the whole Projection Surface.

  • The beams of contiguous video projectors should intersect to create overlapping projection areas. These overlapping projection areas should amount to 15% of a Display’s total projection area.

  • Intersecting video projectors should share Calibration Points in their shared projection area.

  • Press [D] on the keyboard or click on the gear icon button to access the 3D Scene module’s Settings menu and click on the [Display Grid] toggle if the Display Grid isn’t already activated. Once activated, the Display Grid will help you align Displays since the pattern it projects onto Screens exaggerates the blurriness generated by a bad calibration in the shared projection area.

2.7 Display Soloing

When the Calibration mode is enabled, all of the Displays that are connected will simultaneously project/show Display Grids or the 3D object meshes. This can be overwhelming and might create confusion while attempting calibration.

To simplify the calibration process it is possible to select a single Display out of the group and mask the output of the other Displays.

Solo a Display

In the Calibration Tools Window Display list, [Right-click] on the entry corresponding to the Display you want to solo. A contextual menu will open.

  • Select {Solo} from the contextual menu. You will notice that the Eye icons located to the right of each entry in the Calibration Tools Window Display list will feature a strikethrough, except for the Display that was calibrated solo.

If you wish to "unsolo" the Display, repeat the same action.

The solo function will remember which Display you have masked (or not) when you “unsolo.”

2.8 Default Camera Selection

The 3D Scene Preview features a Default Camera through which you can see the virtual stage space. This Default Camera has a fixed visual field and is not represented.

If you want to visualize the virtual stage space with a different visual field or use a Display’s or Camera Object’s point of view, you can change how the Default Camera is assigned. For example, you could use a Display such as a video projector to act as the Default Camera, to see what lies in front of it. (This is a good way to verify if a Projection Surface is in a Projector’s visual field). You can also use this feature to verify if video cameras are aiming in the right direction.

A dropdown menu located in the top-left corner of the 3D Scene window will allow you to change the Default Camera’s attributes.

  • Click on the {Default Camera} dropdown menu and select the Camera, Display or Virtual Projector you want to use as the 3D Scene Preview’s new point of view.

If you select a Camera as the new point of view and move it around in the 3D Scene, you will modify its parameters.

You can select calibrated Projectors and Cameras as points of view, but you will not be able to move them or change any of their parameters because the Calibration process locks their position and orientation.

2.9 Blending

Multiple projectors are often used to create a seamless video image on a Projection Surface. For calibrating multiple projectors PHOTON features automatic edge blending, a process through which the projected images are altered to seamlessly blend into one another.

PHOTON automatically calculates Blending masks when a user is calibrating. The only decision a user has to make is to determine whether the Blending is static (once the Calibration process is complete Blending masks are saved and applied to the video outputs) or done in real-time (the Blending is calculated every frame — which is useful if Screens or Video Projectors are moving during the show).

Enable Blending and Select Blending Mode

Make sure the 3D Scene module’s current mode is not set to [Modeling]. Access to the Blending Panel is not possible when [Modeling] is selected.

  1. To open the Blending Panel, click on the [B] button located in the top-right corner or the 3D Scene window.

  2. Click the [Enable] toggle to activate Blending (see img)

  3. Select one of the following options from the Blending mode dropdown menu:

p-space 3.5 (RT GPU)

RT GPU stands for Real-Time Graphics Processing Unit. This Blending mode uses the

Server’s graphic card (the GPU) to calculate Blending masks for every frame (hence, in real-time). p-space 3.5 (RT GPU) should be selected when a project involves moving Projection Surfaces or moving Video Projectors. This is the most demanding Blending mode and should be used concurrently with Blending Channels to reduce the load on the servers.

p-space 3.5 (static)

This Blending mode uses the same algorithm as the p-space 3.5 (RT GPU) but it is only computed once (not in real-time). Therefore, this Blending mode should be used when dealing with static Projection Surfaces and Video Projectors. It is the least demanding Blending mode and is useful when projecting on very large static structures (which usually involves very large video files). If p-space 3.5 (static) is selected, a [Compute Mask] button will appear. The Blending mask will be calculated every time you click on this button, making it possible for you to recalculate masks if there are changes in the Calibration.

p-space 3.4 (GPU)

This Blending mode is legacy. (It is kept in the software to support older projects.) It is outdated and should not be used.

2.10 Calibration Lock

Once a Calibration is complete, it is possible to lock it in order to avoid unintended modifications (for example, accidently clicking in the Calibration Tools Window Preview could void a perfect Calibration if it isn’t locked).

Locking a Calibration

  1. Press [4] on the keyboard or click on the [Calibration] toggle to select the 3D Scene module’s Calibration mode.

  2. Click the Calibration Lock button located in the top-right corner of the Calibration Tool window.

Locking All Calibrations

  1. Access the Settings Panel by clicking on the Settings button.

  2. Click on the [Controls Locked] toggle to lock all Calibrations.

[Controls Locked] will lock Calibration for all Displays. Following this, it will be impossible to add new Calibration Points, manually move Displays (for both position and orientation) or attempt Auto-Calibration.

2.11 Apply 3D Transformations to Objects and Freeze

2.11.1 Scale, Translate and Rotate a 3D Object

It is possible to modify the shape of a 3D object in order to match the ratio of the real-world prop, set element, screen structure, etc. it represents. You can also position and rotate the 3D object in space to match the position and orientation of the real-world prop.

Why Apply 3D Transformations?

Scaling, positioning and orienting are crucial in stage contexts where many real-world projectors cover many Screen Surfaces. Under these circumstances, it is important to accurately represent the spatial relations between all objects in PHOTON’s virtual world. If the spatial relations between objects aren’t accurately represented it won’t be possible to complete the calibration process.

Scaling, positioning and orienting are not crucial in stage contexts involving single Displays linked to single Screen Surfaces that act as autonomous pairs. However, doing so is considered a best practice and will give you access to a realistic pre-visualization of the project.

Project pre-visualization is one of PHOTON’s key features. VYV’s software can create full 3D simulations of the real-world stage space. In the 3D Scene module Screen Surfaces (with their video content), Displays, cameras, lighting equipment, and set elements can be placed in a virtual space that provides a complete overview of a project.

Applying 3D Transformations

An object’s size, position or orientation (Decorative Objects as well as Projection Surfaces) in the 3D Scene can be modified using the Transformations Panel or Transformation Manipulators.

Transformations Panel

The Transformations Panel contains multiple sliders that allow the modification of the Scale, Translate and Rotate parameters for each axis (X, Y and Z) for any object previously created in the 3D Scene module.

  • Select the object you want to alter by clicking on its entry in the Scene Primitives list.

  • To open the Transformations Panel, press [T] on the keyboard or select {Window > Transformation} in the 3D Scene’s main menu.

  • To change the geometric coordinates of an object, adjust the value of the sliders. You can adjust the value of a slider by manipulating it with a [Click+Drag], or you can [Double-click] on it to open a text field where you can enter a desired numeric value.

The effects of these transformations can be seen in the 3D Scene Preview. The visual representation of the selected object will be modified as well.

Slider values differ depending on the parameters they represent. The Scale sliders are not dimension sliders; they act as scaling coefficients applied to the object’s original size. For example, if the scale value of a cube featuring edges of 2 meters is changed from 1 to 4 on all three axes, the cube will now have edges of 8 meters. The Translate sliders express a value in meters. The Rotate sliders express values in angles. And the Rotate Axis sliders are used to apply a rotation expressed in an angle that corresponds to specific vectors. For example, an angle is set with the first slider while the three other sliders represent vector values for each axis that will determine how the rotation will be applied to each.

Transformation Manipulators

The Transformation Manipulators facilitate direct modification of a 3D object’s parameters —Scale, Translate, Rotate — by manipulating your mouse in the 3D Scene Preview.

Enable the desired Transformations Manipulator using the following methods:

  • Scale Manipulator: Press [X] on the keyboard or click on the Scale button located in the top-right corner of the 3D Scene window.

  • Translate Manipulator: Press [V] on the keyboard or click on the Translate button located in the top-right corner of the 3D Scene window.

  • Rotate Manipulator: Press [C] on the keyboard or click on the Rotate button located in the top-right corner of the 3D Scene window.

The Transformation Manipulators will appear when a 3D object is selected.

PHOTON’s Manipulators feature a standard color-scheme for its 3D coordinate system: X is red, Y is green and Z is blue.

  • [Click+Drag] the handle of the axis parameter you want to modify (X, Y or Z). The handle will become yellow when selected.

  • The Scale and Translate Manipulators feature a yellow dot at the intersection of their axes. [Click+Drag] the yellow dot to simultaneously apply transformations to all axes.

Enabling a Manipulator will disable camera movements in the 3D Scene Preview. To switch back to camera control, press [S] on the keyboard or click the Camera button located at the top-right corner of the 3D Scene.

If you want to control the camera while a Manipulator is enabled, press and hold [S] on the keyboard. This will allow you to manipulate the camera. To switch back to Manipulator control, release the [S] key.

2.11.2 Freeze Transformations

Freezing an object’s Transformations sets its current size, orientation and location as the new default values without modifying the object’s geometric coordinates.

Freeze an Object

  • Select the object by clicking on its entry in the Scene Primitives list.

  • To activate the Transformations Panel press [T] on the keyboard or select {Window > Transformation} in the 3D Scene main menu.

  • Click on the [Set Freeze] button located at the top of the Transformations Panel.

  • If you want to revert to the object’s initial parameters, you can unfreeze it by clicking on the [Reset Freeze] button located at the top of the Transformations Panel.

Why Freeze?

Freezing an object sets its Calibration Points directly in relation to its new position in the 3D Scene Preview. Calibration Points are created out of a 3D object’s vertices and are the main features used during the calibration process. Therefore, it is crucial to alert the software through the [Set Freeze] command if a 3D object’s geometric parameters have been modified before starting the calibration process.

Furthermore, 3D objects in PHOTON can be linked to position and orientation data (provided by stage automation and tracking or animations). These 3D objects will move in the real world but you will want to retain their original geometric data for the purposes of display calibration. Freezing makes this possible, and facilitates accurate projection on surfaces that move.

2.12 Decorative Objects

In the 3D Scene it is possible to add 3D objects that do not act as Screens. These 3D objects can be used to represent technical equipment, set elements, seating, etc. that are part of the real-world stage space, without being used as Projection Surfaces.

PHOTON’s default behavior is to consider any 3D object added in the 3D Scene module as a Screen. As a result, these 3D objects end up being represented in the Timeline module, which might create confusion.

It is possible to declare 3D objects as Decorative Objects to prevent PHOTON from automatically turning them into Screens. As Decorative Objects these 3D objects will not be shown in the Timeline module, and will be taken into account for computations related to video projection.

Declaring a Decorative Object

  1. Select the 3D object by clicking on its entry in the Scene Primitives list.

  2. Press [P] on the keyboard or select {Window > Properties} from the 3D Scene module’s menu to open the Properties Panel.

  3. Click on the first dropdown menu in the {Display Options} section of the Properties Panel to change the default option from {Projection Surface} to {Decorative}.

2.13 LED Screen Calibration

LED Screens are not calibrated in the same way that Projectors are. There are many differences between the instructions for LED Screen calibration and those listed in Section 2.3 Manual 2D Keystone Calibration and Section 2.4 Manual 3D Calibration.

The main differences between these approaches are the following:

Display Type

LED Screens use the LED Processor Display type instead of Projectors. Unlike Projectors, LED Processors are not automatically offered as a default Display when a new video output is declared in the Settings module. LED Processors have to be created in the 3D Scene module and then linked back to the appropriate video output. They are the only other Display type that can be linked to a video output.

Calibration Tools Window Interface

If an LED Processor Display is selected in the Calibration Tools Window list, the Calibration Tools Window interface will change and offer a new set of options that are appropriate for LED Screens.

Calibration Technique

LED Processor Displays use quads (cells featuring a quadrilateral shape) to segment, resize and position video content in a virtual 2D space. The resulting visual composition is then outputted to the real-world LED Processors connected to the LED walls. This approach facilitates content mapping for these devices.

2.13.1 Add an LED Processor

The first step is to add an LED Processor Display in the 3D Scene module. If the project you are working on features many real-world LED Processors, you will have to add an LED Processor Display for each of them.

  1. Make sure the 3D Scene module is open (by pressing [Alt+C] or by selecting {System > 3D Scene} from the Main menu).

  2. Select {Primitive > Display > LED Processor} from the Primitive dropdown menu.

The LED Processor will appear at the bottom of the Scene Primitives list.

The LED Processor Display is not represented in the 3D Scene Preview.

2.13.2 Add a Primitive

While LED Screens are not Projection Surfaces, they still need to be represented by a 3D object. The shape of the 3D object should match the shape of the real-world LED Screen. The selected 3D object is often a plane because LED Screens tend to have a rectangular format.

  • To add a 3D object to the 3D Scene, select {Primitive > Default Objects > any of the objects listed here} in the Primitive dropdown menu

The 3D object will appear in the Scene Primitives list, and a visual representation of it will appear at the origin (0,0,0) of the 3D Scene Preview.

Many ready-to-use 3D objects are available in PHOTON. Referred to as Default Objects, they simplify the construction of the virtual representation of your real-world stage space. Default Objects can be selected from the Primitive dropdown menu {Primitive > Default Objects}.

2.13.3 Scale, Move, Rotate the 3D Object

It is possible to modify the shape of the 3D object in order to match the ratio of the real-world LED Display it represents. You can also position and rotate the 3D object in space to match the position and orientation of the real-world LED Display. Since the calibration process for LED Displays relies strictly on 2D texture mapping (LED Displays are not Projection Surfaces), scaling, positioning and orienting are not crucial. However, doing so is considered a best practice and will give you access to a realistic pre-visualization of the project.

Project pre-visualization is one of PHOTON’s key features. VYV’s software can create full 3D simulations of the real-world stage space.

Applying the Transformations

A 3D object’s size, position or orientation in the 3D Scene can be modified using the Transformations Panel or Transformation Manipulators.

Transformations Panel

The Transformations Panel contains multiple sliders that allow the modification of the Scale, Translate and Rotate parameters for each axis (X, Y and Z) for any object previously created in the 3D Scene module.

  • Select the object you want to alter by clicking on its entry in the Scene Primitives list.

  • To open the Transformations Panel, press [T] on the keyboard or select {Window > Transformation} in the 3D Scene’s main menu.

  • To change the geometric coordinates of an object, adjust the value of the sliders. You can adjust the value of a slider by manipulating it with a [Click+Drag], or you can [Double-click] on it to open a text field where you can enter a desired numeric value.

The effects of these transformations can be seen in the 3D Scene Preview. The visual representation of the selected object will be modified as well.

Slider values differ depending on the parameters they represent. The Scale sliders are not dimension sliders; they act as scaling coefficients applied to the object’s original size. For example, if the scale value of a cube featuring edges of 2 meters is changed from 1 to 4 on all three axes, the cube will now have edges of 8 meters. The Translate sliders express a value in meters. The Rotate sliders express values in angles. And the Rotate Axis sliders are used to apply a rotation expressed in an angle that corresponds to specific vectors. For example, an angle is set with the first slider while the three other sliders represent vector values for each axis that will determine how the rotation will be applied to each.

Transformation Manipulators

The Transformation Manipulators facilitate direct modification of a 3D object’s parameters —Scale, Translate, Rotate — by manipulating your mouse in the 3D Scene Preview.

Enable the desired Transformations Manipulator using the following methods:

  • Scale Manipulator: Press [X] on the keyboard or click on the Scale button located in the top-right corner of the 3D Scene window.

  • Translate Manipulator: Press [V] on the keyboard or click on the Translate button located in the top-right corner of the 3D Scene window.

  • Rotate Manipulator: Press [C] on the keyboard or click on the Rotate button located in the top-right corner of the 3D Scene window.

The Transformation Manipulators will appear when a 3D object is selected.

PHOTON’s Manipulators feature a standard color-scheme for its 3D coordinate system: X is red, Y is green and Z is blue.

  • [Click+Drag] the handle of the axis parameter you want to modify (X, Y or Z). The handle will become yellow when selected.

  • The Scale and Translate Manipulators feature a yellow dot at the intersection of their axes. [Click+Drag] the yellow dot to simultaneously apply transformations to all axes.

Enabling a Manipulator will disable camera movements in the 3D Scene Preview. To switch back to camera control, press [S] on the keyboard or click the Camera button located at the top-right corner of the 3D Scene.

If you want to control the camera while a Manipulator is enabled, press and hold [S] on the keyboard. This will allow you to manipulate the camera. To switch back to Manipulator control, release the [S] key.

2.13.4 Do Not Freeze the Transformations

Is Freezing necessary for LED Displays?

Since LED Screens are not Projection Surfaces, freezing transformations is therefore useless in contexts where they act as Displays.

2.13.5 Map the 3D Object to the LED Processor

In order to calibrate the LED Display you will need establish a link between the 3D object acting as a Screen and the LED Processor. The 3D object must be added to the to the LED Processor’s Objects Reference list.

There is no Visibility list for LED Processors. Once added to the Objects Reference list, the 3D object is automatically “made visible” because LED Displays are not Projection Surfaces.

  1. Select the 3D Scene module’s Calibration mode by pressing [4] or by clicking on the [Calibration] button located at the top-right corner of the 3D Scene window. Once the Calibration mode is enabled, the 3D Scene Preview will turn red and the Calibration Tools Window will open in the lower right part of the 3D Scene window.

  2. Select the LED Display you want to calibrate by clicking on its entry in the Calibration Tools Window list. (If you haven’t renamed the LED Display, it will be listed as “LED Processor.”) Make sure the Display Grid is enabled. The Display Grid will facilitate further operations by showing how the image texture is distributed on the Display.

  3. Press [D] or click on the gear icon button to access the 3D Scene module’s Settings menu and click on the [Display Grid] toggle if the Display Grid isn’t already activated. Add the 3D object to the Objects Reference list.

  4. In the Primitive Preset window section (below the Calibration Tools Window), select the 3D object from the {Object Reference} dropdown menu.

  5. Click on the [Add] button to add the 3D object as a Reference Object.

Multiple 3D objects can be linked to the same LED Processor by repeating the previous steps. Inversely, the same 3D objects can be linked to multiple LED Processors.

2.13.6 Create Quads and Resample Texture

The LED Processor Display uses Quads to resample video texture and assign it to segments of the real-world LED Display. In order to calibrate an LED Display, one or many Quads will have to be created, modified and distributed while respecting the ratio of the real-world LED Display.

Create a New Quad

  • Click on the [+] button located at the top of the LED Properties section of the Primitive Preset Panel in the Calibration Tools Window.

An entry named “Quad1” should appear in the Quad list located below the [+] button. Additional Quads can be created and will populate this list.

Modifying the Quad’s Size, Shape and Texture Mapping

By default, a newly created Quad has the same size as the full resolution of the output it is linked to. A new Quad is “full screen,” however, its size, shape and texture mapping can be modified to fit your needs. This can be done through two different methods:

Using the LED Options Widgets

The right side of the Calibration Tools Window contains many widgets such as dropdown menus, toggles and sliders that you can use to modify the Quad’s parameters. Below you will find brief descriptions of these options (listed from top to bottom, as in the UI):

Primitive This dropdown menu assigns a specific 3D object to the selected Quad. This feature is useful in cases where multiple Screens (represented by 3D objects) are linked to the same LED Processor.

Orientation This dropdown menu rotates the texture inside the Quad by increments of 90 degrees.

[Flip] This toggle enables (or cancels) the geometrical reflection of the texture along its vertical axis.

[Flap] This toggle enables (or cancels) the geometrical reflection of the texture along its horizontal axis.

Texture These 2D sliders will change the size and position of the texture sampled by the currently selected Quad.

Output These 2D sliders will change the size and position of the Quad in the video output.

Setting Texture Resolution The texture resolution has to be set through the Screen’s texture properties.

  1. Select the Screen by clicking on its entry in the Scene Primitives list. (The Screen is a 3D object you previously added to the list.)

  2. Press [P] or select {Window > Properties} from the 3D Scene menu to open the Properties Panel.

  3. Set the desired horizontal and vertical resolutions using the width and height sliders located underneath the Texture section of the panel. (The sliders can be manipulated with the mouse or you can [Double-click] on them to open text fields where you can directly input numerical values.)

Setting Output Resolution You will need to set the LED Processor output resolution so it matches the resolution of its Video Output Port (the graphic card’s physical output).

The resolution of the Video Output Port can be found in the Settings module.

  1. Press [Alt+S] or select {System > Settings} from the Main menu to open the Settings module.

  2. Select the Server and the Output you want to monitor by clicking on the appropriate entries in the Photon Selection list and the Outputs list. The resolution of the Video Output Port should be indicated in a dropdown menu located in the Output Resolution window section.

The resolution of the LED Processor output can be set in the 3D Scene module.

  • Press [Alt+C] or select {System > 3D Settings} from the Main menu to open again to the 3D Scene module.

  • Select the LED Processor from the Calibration Tools Window display list by clicking on its entry.

The height and width sliders located in the LED Properties window section of the Calibration Tools Window can be used to set the LED Processor output resolution.

  • Enter the horizontal resolution value of the Video Output Port using the width slider by either manipulating it directly with the mouse or by [Double-clicking] in it to open a text field where you can enter a numerical value.

  • Enter the vertical resolution value of the Video Output Port using the width slider by either manipulating it directly with the mouse or by [Double-clicking] in it to open a text field where you can enter a numerical value.

Offset the Output The width and height offset sliders can be used to offset the entire output.

The LED Processor’s output resolution has to match the resolution of the Video Output Port found in the Settings module.

Direct Quad Manipulations in Calibration Tools Window Preview You can manually resize and position the Quad in the video output by using your mouse. To modify the texture’s parameters follow these steps:

  • Select the Quad you want to resize or position by clicking on its corresponding entry in the Quads list in the LED Properties window section or [Double-click] on its representation in the Calibration Tools Window Preview.

  • [Click+Drag] inside the Quad to reposition it in the video output.

  • [Click+Drag] the corners of the Quad to resize it.

Holding the [Shift] key while performing the [Click+Drag] actions on the Quad will increase the mouse’s precision.

You will usually input exact values in the Texture and Output 2D sliders located in the LED Options widget rather than perform direct manipulations on the Quads since LED Displays require pixel-perfect precision. However, you can use the manual method to rapidly get a rough preview of the final LED mapping.

The coordinates of the texture’s top-left corner are 0,0 (which is standard in the LED industry).

LED Processor View Modes

You can switch between two different view modes in the Calibration Tools Window Preview when an LED Processor is selected.

  • Select either the {Texture} or the {Output} option from the View Mode dropdown menu located in the LED Properties window section of the Calibration Tools Window.

Output View Mode Shows what is sent to the Video Output Port (the graphic card’s physical output).

Texture View Mode Shows the section of the Screen’s texture that is resampled by the selected Quad.

2.13.7 Assign the LED Processor to an Output

In order to output video from the graphic card connector to the real-life LED Display, you will have to link the LED Processor to one of the Virtual Video Outputs in the Settings module.

  1. Press [Alt+S] or select {System>Settings} to open the Settings module.

  2. Click on the entry corresponding to the Server you want to calibrate from the Photon Selection List.

  3. Once the Server is selected, make sure you identify the Virtual Video Output corresponding to the Video Output Port connected to the real-world LED Display. If the Virtual Video Output is missing, click on the [+] button to create a new one.

  4. Select the LED Processor you want to assign to the Virtual Video Output by using the dropdown menu located to its right.