This page provides information about the content scene requirements in Chaos Arena.
Camera
The camera's location in the scene doesn't matter; it will be locked automatically to the origin of the tracking camera.
If there is no lens tracking, it should be set with the correct Focal length and Film gate (film/sensor width), matching the physical camera that will be used, to compute the correct FOV and inner frustum size for the camera. Camera tracking systems like stYpe and EZtrack can provide a tracked FOV value, which the frustum size dynamically adjusts to. The final FOV can be overridden from the server.
The render resolution should be in the correct Aspect ratio as this will determine the aspect ratio of the projected inner frustum.
The camera Exposure should be set to realistic values. It can be adjusted from operator instances.
The VRayPhysicalCamera has lens breathing simulation, so a reasonable focus distance set is also needed. It doesn't need to be accurate, but for example, if it's too small (like a few centimeters), it can cause significant deviations from the correct field of view and inner frustum size.
The scene can contain many cameras, but it has to be exported with the desired camera for the projection as the Мain camera.
Asset Paths
The scene should be exported either with relative asset paths or with absolute paths that are valid on all machines, for example, on a mapped network drive. Invalid paths can be resolved automatically in many cases, but ideally, all paths should be valid on the machines.
Scene Scale
The scene should have a proper scale with real-world physical units. The camera tracking works with absolute physical units, and therefore the scene should have an appropriate scale according to the desired results. The actual units that are used shouldn't matter as long as the scale is correct and the scene is exported with the correct meters_scale in the SettingsUnitsInfo plugin.
Animations
Not all animations are supported by Arena when loaded from a .vrscene. Some animations can also be too heavy for real-time rendering, like deforming meshes.
The exact frame rate of the scene normally doesn't matter as long as it's set up correctly. It doesn't need to match the synchronization or shooting frame rates unless the "Align Animation to Scene FPS" option is used.
In case the scene includes the stage geometry directly, the stage geometry's position in the scene can be animated.
Stage Position Nodes
If using a separate stage geometry scene in the server configuration, stage position nodes can be used for positioning the geometry in the content scenes.
Stage position nodes are dummy placeholder nodes (a cube, for example) that represent different positions and orientations of the stage geometry without including the actual geometry. They allow for a much more flexible workflow, avoiding scene re-exporting in case of stage geometry changes. They also allow setting up scenes that can be used on different stages without modifications.
The stage position nodes are matched by scene name in the server configuration. Multiple stage position nodes should have the same name prefix that can be specified in the server. This way, they can all be hidden automatically in the renderers, and can be listed in the server UI for easy switching.
All cameras in the content scene also act as stage position nodes automatically.
The stage position nodes can be animated in the scene. The animation is automatically applied to the stage geometry.