This page provides information about the server configuration of Chaos Arena. 

Configuration Files

The server application uses configuration files to define all the parameters necessary for the rendering and camera tracking. These configuration files use the JSON format. They can be edited and saved from the Server UI.

Live editing is available in the UI. The changes are applied using the Apply Configuration button. Depending on the changes, the rendering might have to be restarted, in which case a warning is shown in the log. Camera tracking changes are applied without restarting the rendering.

How to Create Config (.json) from the Arena Server UI

Start arena_server.exe from ..\Chaos_Arena\arena_server\arena_server.exe

General > Global Options

• Set Default Scene Path - a default directory for opening scenes.
  
  
• Set Broadcast Subnet - you can take it from the "arena_spawner.exe" cmd window.
  
  
• Set Stage Geometry Scene - load the .vrscene file you have exported in step 4.
  
  
• Set Stage Position Node Prefix (usually "ArenaStagePosition_" for the scenes provided by Chaos. In your custom scenes, you can use any naming convention.)

General > Global Renderer Options

• Set Env. Viewpoint Node (the scene name of the object)
  
  
• Set Tracking Origin Node (the scene name of the object)

Renderers

• Add the desired number of renderers, including operators.
  
  

• Assign an ID to each renderer. This ID has to match each corresponding spawner.
  
  

• Specify Operator instances.
  
  

• Set Neighbors.
  
  

• Set Projection Node (the scene name of the wall object, or if you're using multiple wall parts - the name of the specific wall part).

Tracking

• Set the correct protocol, port, and camera ID. For stYpe, use ID 0.
  
  

• Vicon and OptiTrack also set the additional protocol parameters.
  
  

• Set the entrance pupil offset of the camera. Note that the values specify the offset of the camera entrance pupil relative to the tracker, not vice versa. For some systems, such as stYpe or Mo-Sys, an offset is usually already entered in the tracking system.
  
  
• Set the tracking origin and orientation. Note that the values specify the offset of the tracking system relative to the projection mesh, not vice versa.

Synchronization

The recommended configuration in most cases is to enable V-Sync and low latency mode and to disable the NVIDIA Quadro Sync.

The NVIDIA Quadro Sync is sometimes unstable in practice. It is not needed with V-Sync and frame synchronization as long as the rendering/shooting frame rate matches the synchronization frequency. On the hardware level, the Quadro Sync system is still essential to ensure that the V-Sync is in phase between all render machines and between the machines and the rest of the system. However, on the software side, the rendering is synchronized between the machines using the frame synchronization feature of the server, and the V-Sync synchronizes the rendering with the hardware.

When rendering at a multiple of the synchronization frequency (for example, 25 FPS rendering/shooting with 50 Hz Genlock in a PAL setup), Quadro Sync has to be enabled to ensure proper synchronization between the instances in case the frame rate drops below the Genlock frequency. This requires the wall to be a primary display in Windows. It means this option doesn't work with multiple instances on the same machine in multi-GPU setups, as only one instance can render on the primary display.

Save the configuration to a file using the Save Configuration… button.