I’ve got a static scene which renders quite nicely at 4 or so hours on a i7-5960x. The resolution is around 5000 in height pixels.
However there is one part of the scene where the rendering slows to a complete crawl (like over 24 hours and counting), I’ve never seen anything like it before.
The cause of the issue are three of four VRayAreaLights and a VrayBlendMtl which is reflecting these lights. The VRayBlendMtl is a road material which has two VRayMtl’s fed into it - they both have a traced reflection depth of 2.
The odd thing is that I have other views of the same scene and the rendering time is all very consistent.
I started rendering on the 20th march at 10:50am, it got to 80% at around 2pm (great I thought), however over 30 odd hours later it is still trying to render this one section and it can take V-Ray about 3 hours for 1% on average from here on.
I am using the new sampler (vray controls subdivs) and 1-24 samples with .015 as the threshold. I also have max ray intensity at 20.
For the moment I’ve just disabled the area lights from reflecting which works but I want to be armed for this situation a little better in future - because it’s just standard stuff in this scene. It is something that didn’t show up until the final batch render.
It will be difficult to provide any solutions without more information and test scene.
Would it be possible to provide a scene for this issue ? What combination of GI engines you are using for for this scene ?
Can you run a quick region render test with use local subdivs Off and see if there will be any difference in the render speed?
I’d be happy to send something in, it finally finished and here’s the crop of the slowdown where it occurred (Around 30 hours). I was using Irradiance and Light Cache.
I’ll try and whip up a reproducible scene.
Obviously that looks like a pretty difficult thing to render but every other angle V-Ray chewed through this scene pretty easily.
