The only case in which I would turn off Branched Path Raytracing is when running a GPU render.
In every other case, BPT will give you a clean render in less render time. Engage BPT.
Post a screenshot of your render settings. Did you give the subsurface samples some samples?
@seachnasaigh I had to give subsurface samples a few or the skin renders greyed out. I am not sure if I have privileges for posting any images here. I don't have any reputation points, so I can't even edit my posts or post more than one every 5 minutes...
I found that turning off BPT gives me a faster render, but the image isn't as good.
phdubrov last edited by
With BPT off you need 60-100 samples (3600-10000 samples per pixel).
BPT will give you a ^clean^ render more quickly. Sure, switching BPT off makes the render complete quicker, but the result is grainy crap. With BPT engaged, Superfly will throw more samples at trouble areas which need it, without wasting time throwing the same number of samples at areas which don't need it.
Set the overall pixel samples (upper Left) high, maybe 50. You can always stop the render once it cleans up.
But if you set the pixel samples too low, the render will finish while still grainy, and there is no way to resume the render and add more samples after the fact. (Such feature has been requested).
And since the skin material uses subsurface scattering, then you ^do^ need to give it some subsurface samples. Maybe even a few more, if the skin is what is problematic. Skin will also be diffuse, so you should also have a few diffuse samples, and a few diffuse bounces. (edit) Ah, OK, looks like you've done those two things. Set the pixel samples to 50.
Whether you use BPT or not, the total number of samples needs to be over 5000.
You're using Pixel Samples 20, which gets squared to 400 per pixel. Then 7 branches = 2800 samples per pixel.
2800 is enough for specific, helpful setups with easy lighting setups.
If the lighting is more complex (i.e. there are small places in the scene that are 10 to 20 times brighter than most other places) then you easily could need 10,000 samples. phdubrov suggests 3600-10000 and that's my experience as well.
I suggested 2000 to 5000 as a MINIMUM, not what you're actually going to need. My point was if you think you have some setup with like 800 samples and you think that's good enough, forget it. That's NEVER good enough.
I just type 999 in the Pixel Samples and I don't stop the image until I'm satisfied with it. Sometimes that's 40 minutes, sometimes it's 50 hours.
Thanks for the replies! I will give it a shot here in awhile, and if it finishes this year I'll post the result.
...if it finishes this year I'll post the result.
Heh heh. And, this is why I am asking for networked rendering. Most folks have a second-string computer sitting around, and maybe a laptop, plus the spouse's or kids' computer. If you could apply all of those cores to a render, it sure would cut the render time down. If you're ambitious, buy a used server blade or two, and really take care of business.
ghostship last edited by
@ghostship It's funny, but that song was in my head when I posted this thread.... ;)