I have a scene which contains multiple building. Using the Object Properties, I am animating the visibility. For some reason during this point in the animation the render time jumps from about a minute to over an hour a frame.
I am using GI with primary bounces at 1 using irradiance map set at medium and secondary bounces at .85 using Brute force.
I am also using the GI Environment (skylight) override set to 1.o with a color of white. The image sampler is set to adaptive dmc.
All the other settings are default.
Can any provide any help on how to correct the rendering time issue?
For this kind of effect, it would be best to render two different sequences (one with, and one without the objects) and composite the transition.
The problem is that V-Ray implements visibility by changing the transparency of objects, and this causes a lot of extra work (e.g. the interior of the objects must now be calculated as well, instead of just the exterior; shadows will be transparent, etc).
Had this exact same problem animating thousands of bricks with the visibility track.
The way I fixed it was to reduce the “Max transp. levels” in the Global switches down form 50 to around 12, which decreased the render times dramatically.
I’m no expert, but you could try putting a VrayColor map in the opacity slot. I found the time comparison to be quicker than rendering two passes or the object hidden solution. But I guess it depends on how may materials you have.
