glass issue ?

[bernhard]

Hello friends !

I just could find out, if a glass object is going through another object, it renders black.

Here a test:


The teapot on the left on top of the white box is fine.
Te teapot on the carpet left too.

In the middle, a glass box that goes through the white one, and on the right, again a teapot that touches the white box.

Hmm, what's wrong ?
I use Vray 1.5 SP1

thx for every little help,
bernhard

[vlado]

You will need to enable Refractive GI caustics for this to work.

Best regards,
Vlado

[bernhard]

ok

basicly you mean to check affect shadows in the glass material, right ?

thx vlado,
bernhard

[DrJan]

He means, in your Render Dialog under Indirect Illumination tab > Indirect Illumination (GI) rollout > check Refractive GI (I think)

[bernhard]

aha..

ok, checked it, new render test.

now I have a very noisy glass material, and I don't have any glossy, not in reflection, not in refraction... the glass should be smooth and clear...

without checking affect shadows:


with checkign affect shadows in the glas mat:


any ideas ?

thx,
bernhard

[vlado]

For the glass box in particular, the problem is that you have overlapping faces on the floor and the top of the diffuse box behind it.

Best regards,
Vlado

[bernhard]

hmm

Hello !

thx vlado, yes, that the surfaces from the box are overlapping is clear.
the teapot on the right is the same, of course the surface from the teapot overlaps to the white box, but isn't there any way to avoid that noise, even if the surface is overlapping ?

thx,
bernhard

[vlado]

I meant that there are faces exactly on top of one another; intersecting objects as such should not be a problem.

Best regards,
Vlado

[bernhard]

hmmm..

ok, makes sense vlado.

@ intersecting objects as such should not be a problem:
well, the teapot at the right is such one, but the noise is also to see.

I made another test, and could find out, that rendering with detail enhancement caused that issue. Turned it off, the noise was gone. Of course, it's more accurate with the detail enhancement.

I increased the subdivs multi to 1 and it looks much better now
I wouldn't say, it's completly gone, but the noise is much smaller.

Do you think that's the right way ?
Or any other ideas ?

thx a lot,
bernhard