Details blockiness using HDRI only...

[Giovanni]

Hi all,
I am having major problems with a scene lit just by HDRI.
I am using IRMAP+QMC, hi quality preset, -6/-4, samples set to 15 for QMC GI, averall subdivisions to 3...

I have hemisph samples to 80 / 30.

Now, the images look good overall, except for the louvers.

Louvers, small planes few inches apart, will render with black splatches.
I know it is about low samples somewhere, but cannot find the right settings.

I tried incresing the irrmap passes, to -5/-3, but it just makes the splotches smaller, and rendering time too high.

I tried the detail enhancement feature, which works, but renders 10x slower, just too slow.

I even tried to take the louvers material out of the GI calculation, and add a dirt map to simulate GI, but of course, there is no direct light into the scene, so the louvers render black....

I increased the sampling for the QMC GI to 20, still no good enough.

How do I improve the quality of such small geometry areas?

I had to increase the irramap interpolation samples, which blurred out the splotches some, but still....


MAX9, RC4,
Thanks for any idea,

regards

gio

[Neilg]

You could always do a crop render of that area at high quality with much higher settings saving it to disk, then render your normal IRmap and merge them together.

[Giovanni]

You could always do a crop render of that area at high quality with much higher settings saving it to disk, then render your normal IRmap and merge them together.

Yea, I have not tried that, but I am sure it would work, althought it would require manual setups and PS job...

You would think that between IRRMAP and QMC GI there would be a way to tell Vray to use more samples for specific geometric conditions, such as small slats...

Anyways....

thank you

regards

gio