Manually generate RenderTexture mips at runtime

Is it possible to write in the mips of an RT manually? The RenderTexture class has both support for useMipMap and autoGenerateMips. Since I can enable useMipMap without automatically generating them, I assume there must be a way to manually write into them. Texture2D already supports that.

I want to create a blur texture, and store the multiple blur levels in the RT's mips. It might not save memory or performance, but it's more ergonomic

 

It can be done using the command buffer version of Blit which takes a RenderTextureIdentifier which includes the mip level to blit to, or you can use CopyTexture, or a compute shader. Note: you cannot do a blit with the same render texture as the source and destination, so you have to create intermediate render targets and either blit or preferably CopyTexture into each mip after generating the blurred version. Compute gets around this by way of using a RWTexture.

 

Thanks @bgolus. In the end, I've decided to use only one blur iteration, so I don't need the mips anymore, but I'll keep this in mind for some other project

 

just noting, RWTexture both reading and writing to itself only works on newer GPUs. feature level 11_0 doesn't seem to support this, even in compute shaders (learned the hard way)