I made a patch to speedup cycles for interior renderings. I use it since many month in production for archviz and propose to get it in master for everyone to benefit from it. It works for CPU, OpenCL and CUDA rendering. On current master, I get 1.5x to 2x faster rendering with my patch only, depending on the scene and the platform:
Similar gain are obtained by first testers on CUDA.
How does it work?
It’s an optimization of the AO approximation option to react differently on glass, metal, etc. making it usable in many difficult scenes. In most scenes, you just have to set a value to render 1.5 to 2x faster. Depending on your taste and the mood you want to have, you may add a light behind the camera to obtain the wanted contrast.
To better understand, 2 examples:
The classroom scene with only one parameter changed you get a 1.5x faster render:
Using a professional scene from Chocofur, changing one parameter and adding one light (tweaking strength and color in viewport render, it takes maybe 30 seconds to do both action), you render in 11minutes, compared to 22minutes on master:
You could also have changed only the parameter and get the same speedup and higher contrast. It’s your artistic decision.
How can I get it?
The patch will be published for review, so it may be in the next 2.8 version next year. If you donate (see link beneath), you can benefit from it right now. Just give your email and if you want a stable (2.79 release) or master (latest code) build. You will also get the Classroom file configured so that you can see how it’s done.
you can donate here https://www.paypal.me/matmenu
Who are you?
I work on improving cycles for many years now, for my own usage at work (mostly architectural and urbanisme visualizations). But I also provided many builds for free here and the according patches like 2048 max texture in OpenCL https://developer.blender.org/D1530, selective compilation of transparent shadows https://developer.blender.org/D2339 (both in master), https://developer.blender.org/D2340 and https://developer.blender.org/D2341 which brought significant speedups before the kernel rewrite. See https://blenderartists.org/forum/showthread.php?414980-OpenCL-denoising-and-speedup-thread&p=3147092&viewfull=1#post3147092 for example.
Is it only for GPU or a specific card?
No, it works for all CPUs and GPUs supported by Blender. On an I7 6700K, the chocofur scene renders in 35min45 instead of 53min59.
Does it work well with denoising?
It does, even with scrambling and other options. I didn’t use it in pictures above to showcase only the patch. Here you can see a render made in 2min11 down from 21min48 using the patch, denoising and scrambling. Donators can ask for the details.
Will it work in all cases?
It is made primarily for interiors and was intensively tested in still interiors, first test in animation showed it is stable. For exteriors, you may see benefits, but it’s not tested. If you want your money back, just ask it in the first 30 days.
Can you ensure it will be in master?
I can only guarantee my part. Like all developments, even those made by the Blender Foundation itself, it has to go through review first. But I will provide builds to all donators to ensure they are able to use it whatever happens.
What happend if the money donated is too low?
The full patch is released here https://hastebin.com/sexevejaqa.diff, so you are safe already on this side. Donators get the 2.79x (so a,b,c, too) releases with the speedup. On demand, you can also get one build on top of current master (depending on the donation, more custom builds can be done). So the only think that depends on the 3000€ is: do I work further for the community? If you see more patches coming, the answer will be yes.