I have some suggestions for viewport rendering in Cycles. As is known render speed depends on resolution. The bigger is your working area the greater resolution must be rendered. I think when when working on materials and lighting we rather don’t care about the quality of the render. Instead we need instant feedback. I’m right?
I’m Working in Cycles since 4 month. In this time I watched hundreds of tutorials and noticed two methods of how people deal with resolution vs speed thing. The first method is to set the tiny 3D view surrounded by bunch of other windows. Probably with second 3D view and and Node editor, even if they render simple diffuse + glossy mix. Something like that.
Second method is to set render region in the center of screen and zooming out whole scene to fit it in that area. See the picture.
Both methods come down to having a tiny image you’re staring at while sniffing your monitor.
I came up with an idea that could solve this problem. This is nothing new because many video editing and compositing programs have same thing.
As the thread title says, its about the dividing render resolution of viewport and upscale it to actual window size. Cycles will be doing exactly the same thing as rendering this tiny images so it will be fast but result can be seen on bigger area. Image will be pixelated of course but as I mention- we need fast results, not final quality.
Rendering image with dots made of 2x2 pixels will take 1/4 render time than full resolution. Dividing resolution to 1/9 (3x3 pixels dots) reduce time to 1/9 and etc. Of course, we must add BVH calculations ans stuff but you know what I mean.
Icons responsible for the dividing render should be close at hand so the best place is next to pause render button. By the way, if you have a small window (first image) then sliding the header to jump to the pause button is a little annoying.
It is worth noting that this will be very useful when someone is working on a huge resolution. For example the Retina HDPI on the MacBookPro. Of course, large pixels don’t look as nice as a full render but imho this might be more practical than sniffing your display.