What is velocity camera? Causing trouble with rendering.

[yjchun]

I am rendering game scene to RenderTexture using Camera.Render(), as it is.

On flight scene with FX effects, result image is not correct.

I found a camera named "velocity camera" is the cause. without it, image is perfect. What is this camera? I couldn't see noticeable difference on the game screen when that camera is just disabled.

Below images are from same screen, left with velocity camera enabled, right with disabled. In Left image, velocity camera with depth=0 overdraw all with white but angled plane, even covering UI canvas.

Thanks.