(i am not native english speaking, Sorry for bad english)
Let me explain that idea by an example suppose i have a scene with some 3d modals and or may be some fixed lights or may be moving lights and moving camera. i want to render each subsurface(square have only 4 subsurfaces) of each modal once after that i don't want to rerender those subsurfaces i just want to perspective transform those rendered subsurface according to camera that will going to be easy and takes very less time to render.
suppose i just calculated the ammount of light on those subsurfaces going to have in each frame and render a new version of that subsurface if it have different amount of light and store those values somewhere.
Now we have each rendered subsurfaces (only those whom are visble in any frame) with different-different ammounts of light.
Now just place those subsurfaces in each frame with perspective transform according to camera and according to ammount of light on that subsurface that we stored somewhere.
this is very usefull when we have to render a sence having only moving camera (most of the VFX videos are those types)
is that way can reduce rendering time or is that possible ?
