My specs are
- CPU: InterCore i5-4670K @3,4Ghz,
- GPU: NVIDIA 660GTX
Scene setup is the same:
- 128 PathTracing samples on CPU device.
- Sobol sampler
- ray depth 6
- light – HDR env probe
- material setup is the same (contains most used materials – diffuse, glossy, metalic, glass)
And here are the results (btw. description on image is wrong, It should be CPU not GPU):
As you can see in image above, Cycles is fastest, but render has more noise than Mitsuba. LuxCore is slowest, and has more noise than both Cycles and Mitsuba. But still new LuxCore 1.5 renders are a lot faster than old LuxRender.
One more test in darker place. LuxCore quality is getting closer to cycles in darker scenes:
GPU test – tile size set to 128. Cycles Cuda vs LuxCore OpenCL on NVIDIA 660GTX. CUDA are always faster than OpenCl on Nvidia, so maybe results could be different if we compared LuxCore on AMD GPU, but I do not have one.
CPU SPEED: Mitsuba wins giving faster renders with less noise. Cycles takes second place and Lux third (new luxCore 1.5 is way faster than older LuxRender – up to 10x!, but still not as fast as Cycles). Another advantage of Mitsuba are additional integrators eg. Photon Mapping is great for indoor scenes, caustics, etc. Lux has also other integrators than PathTracing, but usually is not as fast as above.
GPU SPEED: Cycles wins, but maybe LuxCore on AMD GPUS will bee faster? Will have to wait and see. But on my NVIDIA 660GTX Cycles is faster with Cuda, than Lux with OpenCl, but that is to be expected. Cuda>OpenCL on Nvidia. Mitsuba do not have GPU support.
LuxRender – easy to setup lightning, quite easy setup of renderer, has realtime vieport rendering, easy and good looking sun&sky lightning, node based materials (soon) gives lots of flexibility (but not as much as Cycles), renderpasses, displacement, strands. But no fast/easy solution for SSS.
Mitsuba: easy to setup render – just set number of samples and you are good to go, easy lightning, good and easy sun&sky setup, basic renderpasses, basic sss. But it lacks lots of features: no vieport rendering, just basic strands support, no node materials, no displacement.
Cycles: it is most powerful but hardest to learn into IMO. Some features works only in ‘experimentl’ mode. It supports: complex node materials, realtime vieport rendering, fast sss (best of all above), renderpasses, fast but complex to sun&sky setup, displacement, motion blur. There are lots of sliders to adjust render speed vs quality, but they are not user friendly and you may find yourself wasting a lot of time adjusting those. Mitsuba is way easier here – just one slider ‘number of samples’, gets the job done in 90% of cases.
Also you may find that Cycles gives bad looking glossy reflections for hight values of roughness eg see here. There is node setup that solves that, but again it is not easy to fix. So I could say for Cycles ‘with great power comes great responsibility’ :D.