I saw this page https://docs.arnoldrenderer.com/display/A5AFCUG/Denoiser
but still feeling very confused afterwards. Is there a video demonstrating how it is done by any chance? There's a very clear noise on GPU rendered version compared with CPU.
I also get some warning [c4dtoa] 00:00:00 1826MB WARNING | parameter "step_size" is declared already. Not sure if this has anythign to do with it.
the option for optix denoiser tickbox seems to be missing in the AOVs -> beaty -> right hand side. Is this the wrong place to look for it? or has it changed location?
anyway this resolved my answer
https://answers.arnoldrenderer.com/questions/33103/view.html
If you want to denoise a single frame, you use an Imager.