Pre calc is making render take longer - NOT Blended IR

V-Ray V-Ray for 3ds Max Issues
1

I am using Max 2009 64 bit with Vray 1.5 SP3a

I’ve never had a problem using precalculated GI before. But in this scene I am working with, for some reason when I precalculate the GI, the render times go up 10x.

I pre calc the light cache, then I pre calc the IRmap with multiframe incremental, then I render. The frames that come out look fine, but are rendering around 50 minutes per frame.

If I just set everything locally to single frame, non pre calculated GI, and hit render it will render in about 5 minutes per frame.

There’s nothing complex in the scene. Only 4 lights (photometric with IES files). Fairly simple materials with nothing above 8 subdivisions.

AA is set to Adaptive DMC: 1 and 4

DMC Sample noise threshold: 0.01

Any thoughts?

2

do you have lots of VRaylights in the scene?

3

No, just the 4 photometric IES lights in the scene.

4

Do you have lots of proxy objects or other dynamic geometry in your scene? If yes, then you can try to set the light cache to single frame mode with a very small number of subdivs (f.e. 100).

Best regards,
Vlado