offscreen rendering

Is it possible to run Unity in offscreen mode, using a renderer such as osmesa? I would like to run a unity app that outputs frames to a file from a script without having it open any windows.

You should see the first response to [this question about rendering to file][rendering-to-file], it might be what you’re looking for.

Basically it’s a combination of using [Unity’s batch mode][batch-mode] - which doesn’t render anything, and manually invoking a [Camera render operation][camera-render] followed by reading pixels into a Texture2D (that you then can save).

[batch-mode]: http://unity3d.com/support/documentation/Manual/Command%20Line%20Arguments.html)
[rendering-to-file]: Rendering to file in batchmode? - Questions & Answers - Unity Discussions
[camera-render]: http://unity3d.com/support/documentation/ScriptReference/Camera.Render.html