Page 1 of 2

Refraction issue

Posted: Mon Nov 16, 2015 6:52 pm
by Micha
Hi,

I rendered a scene for client per Vray and later I tested Octane with the scene, but the refraction looks wrong now. What did I wrong? The transparent cap looks like massive glass. I extracted the inner surface for some extra tests and found, there is no big difference if I join the cap objects (red/black) or not. Any idea? Attached a simplified scene.

Cioa,
Micha

Re: Refraction issue

Posted: Mon Nov 16, 2015 8:40 pm
by formatio
Hi

It looks to me like the ray hits 2 surfaces (in - out), and should 4 (in - out, in - out)

Are you sure your glass box has thick walls?

Regards,
Mac

Re: Refraction issue

Posted: Mon Nov 16, 2015 8:49 pm
by Micha
Yes, I joined the red and the black part, the same wrong look.

I did a quick test with Vray now - separate parts looks like Octane, joined parts looks right. So, why Octane doesn't show the right look?

Re: Refraction issue

Posted: Mon Nov 16, 2015 8:52 pm
by formatio
Correct me if I am wrong:

Generally you have 2 cubes one inside other - 12 surfaces in total - Yes?

Re: Refraction issue

Posted: Mon Nov 16, 2015 8:57 pm
by Micha
If the object is joined and should show the right look, than there are not two cubes, there is one cube with thick walls, but open at the button (so that inner and outer surface are connected like a real world object).

Re: Refraction issue

Posted: Mon Nov 16, 2015 8:58 pm
by formatio
OK - I know what is the problem.

In general - Rhino is a surface program so two cubes are seen as two solids - one inside another.
If you want it too look like a thick glass it must have a hole in it.

Re: Refraction issue

Posted: Mon Nov 16, 2015 9:04 pm
by Micha
No, it are not two cubes. It's like wine glass in cube shape, all surfaces are connected at the right places. Let us wait for Paul. ;)

(screenshot - upper part is the single cube object with thick walls and hole and the bottom.)

Re: Refraction issue

Posted: Mon Nov 16, 2015 9:08 pm
by formatio
Hmm - Is your material correct then?

Surfaces don't need to be connected to work and look like glass ;)

Re: Refraction issue

Posted: Mon Nov 16, 2015 9:53 pm
by face_off
Adjust the Kernel->Ray Epsilon.

Paul

Re: Refraction issue

Posted: Tue Nov 17, 2015 7:37 am
by Micha
Great, simple solution. :)

Thank you,
Micha