- Aug 1, 2018
- 305
- 2,811
The downsampling trick is a good one, but what is this nonsense about iterations? Do you actually understand what an iteration in iRay is? That's now how it works at all.I am an fan of using down-sampling personally. Currently my renders are set to stop at between 100 and 200 iterations, dependent upon the scene complexity (number of light sources). Typically I use a 2:1 down-sampling ratio hence my renders in terms of time are equivalent to 400 to 800 iterations without down-sampling. I render --> denoize --> reduce image size.
The very high iterations used by many users reminds me of a definition of insanity.
Insanity is to repeat something many times with the exact same starting conditions, expecting to get a different result.
Once you get past 100 iterations, each successive iteration adds very little data to the final result. By rendering at a higher resolution, you gain more data at way fewer iterations. Once you weed out the anomalies (denoizer - external program), you are left with a far superior set of data.
For simple materials and shaders, yes, 100-200 iterations will be good enough, but for complex ones, like glass/high glossiness, transparency and so on, not even close. You need at least 1000 - 2000 iterations to make it look decent.
Of course, if you goal is to have everything in your image look like polished metal/plastic, why even bother using PBR Materials, if you don't care about the final result...