Physical Sky Background and Glass

jibberishballr · Sep 2013

So here's my current WIP using linear workflow and Mental Ray. I have glass where the window is, and the physical sky is seen through the window(I'm using physical sun and sky with an area light (portal light). The "use background" is checked and left blank, but when I render out my scene (32 bit exr) I get the image you see below. I want to have a transparency layer so I can throw in a different sky in post. Any Ideas?

o2car · Sep 2013

Cant you use whatever sky you want in post as an IBL instead? I mean if you change it it wont match your indirect light thats baked into your scene.

jibberishballr · Sep 2013

I haven't tested it, but I remember reading that mixing IBL with FG will cause issues, where the FG rays don't work properly

I also tried putting an HDR image in the haze channel of the sky shader but no real luck...

.Wiki · Sep 2013

When you use HDRI with mentalray or vray or whatever renderer you need to blur the HDRI.
You need a camera switch shader which seperates Glossy, Diffuse and Reflection Rays.

The blurred HDRI is for GI only while the sharp HDRI files affect the reflections and Refractions.

When you save your EXR have you set the alpha correctly?

jibberishballr · Sep 2013

.Wiki wrote: »

When you use HDRI with mentalray or vray or whatever renderer you need to blur the HDRI.
You need a camera switch shader which seperates Glossy, Diffuse and Reflection Rays.

The blurred HDRI is for GI only while the sharp HDRI files affect the reflections and Refractions.

When you save your EXR have you set the alpha correctly?

I believe it is set up correct, but maybe I am missing something. Under Renderable Cameras I have the alpha channel(mask) checkbox checked,32 Bit Framebuffer, and EXR format...Anything else I'm missing?

Physical Sky Background and Glass

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