--- title: "Content Scene Requirements" canonical: "https://documentation.chaos.com/space/ARENA/124391338/Content%20Scene%20Requirements" format: markdown --- 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. 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. Operator instances can adjust it. 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 with **relative asset paths** or **absolute paths valid on all machines**, such as 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; therefore, the scene should have an appropriate scale according to the desired results. The actual units used shouldn't matter if 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, like deforming meshes, can also be too heavy for real-time rendering. The exact **frame rate** of the scene usually 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. If the scene includes the stage geometry directly, the stage geometry's position in the scene can be animated. ## **Stage Position Nodes** --- Stage position nodes can position the geometry in the content scenes if a separate stage geometry scene is used in the server configuration. 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 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.