Vray rendering small geometry black

[Zippydan]

Hi, can anyone tell me how to prevent the problem of VRay rendering objects that are small within a frame black?

I seem to remember there was a parameter that one had to adjust to prevent this, because it meant that Vray hadn't calculated enough information for that particular small pixel area, but doesn't come to mind at the moment.
Is it something to do with the numer of samples?
I know one alternative would be to render bigger, but I'm already rendering at PAL resolution.

I'm currently using:

- the Adaptive DMC sampler (min. subdivs = 2/max. subdivs = 5);
- Irradiance Map for primary bounces ( subdivs = 50/Interp. samples = 30/Interp. frames = 2);
- Light Cache for secondary bounces.


P.S: I'm rendering a character animation with the Pre-pass and Render pass workflow.

Thanks in advance to anyone who can help.

[vlado]

Can you show just that part of the image?

Best regards,
Vlado

[mr furious]

if your scale is really small you might want to adjust your shadow bias as your object may be smaller than the shadow bias. Just a guess.