Question Access The Camera's Opaque Texture Through Script

I wanna create an image effect through shader graph (by making a blit on the forward renderer), and that effect requires me to get the average color of the current camera view (and render textures are too slow for me). So using the opaque texture is the only way (that I know of) to do that, the problem is that I don't know how to access it. Is there anyway to access it through script? So that I can then pipe it to shader graph?

 

I think you just make a texture named _CameraOpaqueTexture in Shader Graph and it automatically binds it.

 

I ended up making the effect I wanted in an image effect shader, but thanks for the info!