Question Are rendertextures double-buffered?

Hey all,

I'm trying to render some values into a RenderTexture... but using a mesh (with values baked into the colours) that moves around with a GameObject. The RenderTexture is not cleared each frame by the camera, so values accumulate. But what I'm seeing is that when my GameObject's mesh moves across the surface of the render texture fast, I get flickering in the rendering. My only explanation is some sort of async/race issue - or more likely, RenderTexture's are double-buffered and as my object mesh moves fast, one buffer renders it in one position, then the next frame, the next buffer renders in a slightly different position.... and then when the RT is rendered, we get flickering as it flips between these two buffers?

Note: This is a normal RenderT exture asset. Not a Custom Render Texture (CRT). I have tried with a CRT with double-buffer unticked - still flickering.

Thanks in advance for any info or help.

Using URP. Unity 2021.2.7f1

 

Render textures are not double buffered. They are simply single buffers themselves. Custom Render Textures are just a wrapper that provides that kind of functionality.

 

Good to know, I will rule that out then. It's very bizarre, perhaps a precision issue... or maybe it's because the rendertexture is subsequently used by the compute shader - maybe the system doesn't take into the account that they're a shared resource and the render must happen before the compute shader.

 

Would be best to make a new post about the flickering problem and supply code. Some heads won't usually respond without more info.

 

Hey there, did you fix the flicking? Perhaps the flicking is actually caused because the render texture is not double-buffered indeed. I am looking into it although it's not a crucial matter to me right now!

 

I did fix it actually, but now I'm struggling to recall what it was exactly. I know that it wasn't related to the rendertexture being double-buffered or not. If I recall it was something to do with whether the main camera was outputting an opaque texture or not - possibly because of the way the shader was referencing the texture.