problems with sunlight shining through glass in vray 1.5

[bripatfan]

I have just upgraded to vray 1.5. I scene I've been working on in the previous version has a standard direct sun light shining through a glass window. Since I upgrade to 1.5, the light from the sun is no longer shining through the window. I've tried rendering without the windows in the scene, and the light comes through, so I'm pretty sure the problem is with my glass. I've tried it with the Vizmasters Simian glass and a normal glass vray material. Affect alpha and affect shadows are both checked, but still no light is coming through. What do I need to do to let the light shine through the glass?

[Brian Smith]

assuming that your material is built with the correct transparency, it sounds to me like you're not using vray shadows on the light

[bripatfan]

No, I am using vray shadows. I also tried it with the new vray sun and that didn't work either. I'm almost positive the problem lies with the material, or with some settings regarding the material.

[Brian Smith]

just create a new vray material from scratch and change just one thing...make the refraction color gray (instead of black)...if that allows light to come through then build the material back to the way the other is, changing one parameter at a time and rerendering each time until you find where the problem lies

[bripatfan]

well, my refraction material was set to white to begin with. Do you mean gray instead of white? Either way, I tried it with gray as the refraction color and nothing changed.

[Brian Smith]

i understand that...start over with a completely new vray material and change just the refraction and retry...you have to isolate the problem and this is a great way to do it...kind of reverse engineering

[Sawyer]

2 things to keep in mind with vray "glass" mats.
1. check the box that says affect shadows.

2. There is a bug with mulit-sub object materials that light will not come through.

http://forums.cgarchitect.com/20653-...i+object+glass

recent post with work around

[bripatfan]

Oh, okay. gotcha. from scratch, just change the refraction to gray...did that, still no light coming through.

[bripatfan]

Thanks Sawyer, that work-around worked...around.

What a huge bug to have. They need to get that fixed quick.

[creasia]

The Chaos forum suggested embedding the glass within a Vray Blend material.

This way all you have to do is click on the material button in the top right corner and select VrayBlendMtl and keep the old glass as a sub material.

Nice quick fix, especially if you have an established material library.