I know that there are several ways to make Cycles render a lot faster. I know I can turn down sampling, set tile size to 16 x 16, decrease the number of render layers among other things to make renders faster in Cycles. However, I was wondering, would anyone be able to offer some maybe not so widely known tips and tricks to make Cycles render faster? Currently, I’m doing all of the things I mentioned and sometimes renders take around 30 minutes to complete. GPU rendering isn’t an option for me.
There’s a million configs you can lower to get faster render times, bounces, you can clamp to converge faster… I haven’t used this that much but it was an eye opener when I saw it.
I checked out the video that you showed me and I think it’ll help a lot. Thanks! As for the clamping thing you mentioned, I can’t seem to find that option. Do you think you can help me find it?
EDIT: That baking trick cut my time in half!
Nice. In render settings, sampling, there is clamp direct and clamp indirect. Usually you use clamp indirect. 0 = no clamping, and you might experiment with different values, it basically clamps or limits the intensity of light that a ray can contribute, so if you set it really low .01 you are saying a ray can’t have more than this amount, this will reduce fireflies, the result will be that the render may look quite dark and your levels will be badly skewed, glass and other glossy material may look bad. So you increase it to 1, or 2 (higher has less of an effect) The idea is to reduce fireflies primarily, althougH it can reduce noise as well. It doesn’t make the sample count go any faster but your image will be cleaner faster, so you need less samples, the bad part is that glossy materials may look like crap.
For glass, use the ‘sahdow ray’ trick,
You can also add large but weak mesh lights in certain scenes to get clean.
Using environemntal lighting can help
In general you need alot less bounces than you think. Quite often 3-4 bounces is indistignuishable from 15+
There are also a lot of nvidia cards in the $200 range that are only a shade off the big ones.
“Scenes that look quite dark” and “glass that looks bad” can also be the analog of “exposure problems.” Ordinary photography can have the selfsame problem: no “single set of lights” will do for all. (Darkroom “burning and dodging” is often required to compensate.)
Cycles sort-of dumps a whole bunch of light rays into a box, using the GPU to do the math in-parallel, and waits for the solution to converge. If you have “very different” objects and materials in the same shot, it can either be difficult for the problem to converge or it might do so with a lot of under/over-exposure. I usually use BI and often use layer-specific lights to handle this, using different lights to hit different things and separating them so that they don’t shine on the “wrong” thing that’s nearby. (Which can’t be done in the real world, but CG is neither a world nor real.) You can also use separate renders.
You use Blender Internal? Are you able to get realistic results from this?
Where can i find that clamping… im testing baking and takes about a hour to render a 2k map???
You should get better time than that even. Check your optimization.
What do you mean by, “Check your optimization?”