Page 1 of 1
Images through glass window get deformed
Posted: Sun Mar 23, 2014 7:24 pm
by kmito
Hi,
It seems that Octane causes odd unrealistic refraction to glass and the image coming through the window gets deformed. Does anyone know how to fix this problem? Thanks,
Re: Images through glass window get deformed
Posted: Sun Mar 23, 2014 8:09 pm
by roeland
The glass is probably modelled as just a single plane. The Octane glass material only refracts correctly when the windows are modelled as a volume (i.e. with a front and a back side).
--
Roeland
Re: Images through glass window get deformed
Posted: Sun Mar 23, 2014 10:49 pm
by kmito
This particular skylight is a GDL object I downloaded from a manufacturer. The glass opening consists of 3 layers of glass pane, each has 1/4" thickness. I thought the refraction was caused by these overlapped multiple glass layers, so I converted the GDL object to morph elements and removed the 2 glass layers and rendered again but that didn't make any difference.
I tried another window opening, a generic ArchiCad window which is made of a single 1/4"thick clear glass material, but the result was the same, the background wall outside the window looked warped in the rendering.
Is there a parameter in the OctaneRender setting to adjust or turn off the refraction of a glass material?
Thanks,
- Kei
Re: Images through glass window get deformed
Posted: Sun Mar 23, 2014 11:03 pm
by kavorka
check to make sure you have smoothing turned off. This can change how the light is refracted if you dont have enough geometry in the glass.
Re: Images through glass window get deformed
Posted: Sun Mar 23, 2014 11:38 pm
by face_off
Definitely turn OFF smoothing for the glass material. Also check your rayepsilon is OK.
Paul
Re: Images through glass window get deformed
Posted: Mon Mar 24, 2014 2:01 am
by kmito
Yes, I tweaked the rayepsilon parameter and found a sweet spot that fixed the geometry!!
I had no idea what the heck rayepsilon was but it worked.
It doesn't look like the same value always work for every view. You have to tweak it every time you find funny geometry. Smoothing was turned off, so that was not the problem but good to know that it may also cause refraction issues.
Thanks so much everyone!!! Now I can sleep well tonight.
- k
Re: Images through glass window get deformed
Posted: Mon Mar 24, 2014 2:48 am
by face_off
Yes, I tweaked the rayepsilon parameter and found a sweet spot that fixed the geometry!!
ArchiCAD contains with both very small and very large polygons (similar to Revit) in the same scene - and they try to economize on polygons to save memory - which of course makes it challenging for renderers to get enough polygon info to do their job. So tweaking rayepsilon is far more important than with other Octane plugins.
Paul