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When using the Irradiance Map and Light Cache I seem to be getting some pretty bad blotchy scenes with the Default Medium setting on the IM. Which values are best to adjust without killing render times and getting the blotches away.

 

Also, I have background Plane and Dome both with Self Illuminated Materials and set to -1.0 for the Alpha...yet my Alpha Channel is still solid white...any suggestions?

VR_RawGI.jpg

VR_GI.jpg

GI_Settings.PNG

View003_40_NE_001.jpg

Edited by dialog
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Hi. Did you turn up the gi multiplier, or is it at 1.0? Try the very low setting. Does it get worse? If not, try add more lights in there. i'd like to see the beauty pass though. Did you try to turn off the plane and dome?

 

No I left it at 1.0. I will re-render a test with super low settings for that. I added the Beauty Pass (Keep in mind I have not set up all my materials with tweaks yet or interior lighting...these are lower quality renders too obviously).

 

THe Plane and Dome are there...very burnt out... but they still have a -1.0 for the Alpha contribution...so not sure why they are still showing up in the alpha as white.

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I got an idea. What about excluding the glass from the self illuminating stuff?

 

How would I go about excluding the glass from that material? I will try it out.

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I got an idea. What about excluding the glass from the self illuminating stuff?

 

Ok, so I hide the glass completely and the alpha is correct. So its an issue with my glass.

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I have background Plane and Dome both with Self Illuminated Materials

 

Why such a weird setup ??

 

Regarding alpha being white, you have to setup your Glass material to have "affect alpha" inside refractive properties.

Your VrayDomeLight has to be set invisible.

 

Blotches in IR are more matter of hemispherical subdivs (which are also governed by DMC sampler's settings, beware) than their preset quality.

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right click on your glass object properties and turn off shadow casting. for the alpha, give your glass a -.5 or so if you want to include reflections when you drop in a background or just render without the glass and render a pass with the glass setup as a mirror and adjust in post. Lots of ways to skin that cat

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Why such a weird setup ??

 

Regarding alpha being white, you have to setup your Glass material to have "affect alpha" inside refractive properties.

Your VrayDomeLight has to be set invisible.

 

Blotches in IR are more matter of hemispherical subdivs (which are also governed by DMC sampler's settings, beware) than their preset quality.

 

I was trying a setup from Everomtions Arch Interiors 29...they seem to use a plane and dome on every set up... not sure if I am liking this lol. The aplha is fixed now after changing it....Thanks!!

 

I may need to send you these files to light my scenes lol

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right click on your glass object properties and turn off shadow casting. for the alpha, give your glass a -.5 or so if you want to include reflections when you drop in a background or just render without the glass and render a pass with the glass setup as a mirror and adjust in post. Lots of ways to skin that cat

 

With no offense, none of this makes sense to me. It sounds like some workaround from 1992 and it's definitely not how Vray should be used.

 

If you want to avoid shadows in glass without true caustics, you check "affect shadows". This creates "fake" glass, that's basically opaque Mirror.

If you want faster interior GI, you check off "visible to GI" in VrayProperties of the glass, but more often that not, it provides meager benefit as the "fake" glass is already very fast and doesn't obstruct GI much at all.

If you want to keep REFLECTIONS on glass, you render against such background, that has the same intensity as the post-production background will have. Only this will keep physically correct amount of reflections.

If you want full (unrealistic) reflections, you render against completely black background. You want to do this anyway for Anti-aliasing reasons with Alpha channel to avoid halo effect.

If you want to add the reflection in post, you can do so in linear compositing, and then you can render against white background or whatever, as it doesn't matter. You don't need to render it as Mirror, that's what the VrayReflection and VrayRawReflection is for.

 

But foremost, don't complicate your life and setup your scene in way that you understand. Because, what's the point in constantly coming up with errors that need the whole public to solve ?

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With no offense, none of this makes sense to me. It sounds like some workaround from 1992 and it's definitely not how Vray should be used.

 

If you want to avoid shadows in glass without true caustics, you check "affect shadows". This creates "fake" glass, that's basically opaque Mirror.

If you want faster interior GI, you check off "visible to GI" in VrayProperties of the glass, but more often that not, it provides meager benefit as the "fake" glass is already very fast and doesn't obstruct GI much at all.

If you want to keep REFLECTIONS on glass, you render against such background, that has the same intensity as the post-production background will have. Only this will keep physically correct amount of reflections.

If you want full (unrealistic) reflections, you render against completely black background. You want to do this anyway for Anti-aliasing reasons with Alpha channel to avoid halo effect.

If you want to add the reflection in post, you can do so in linear compositing, and then you can render against white background or whatever, as it doesn't matter. You don't need to render it as Mirror, that's what the VrayReflection and VrayRawReflection is for.

 

But foremost, don't complicate your life and setup your scene in way that you understand. Because, what's the point in constantly coming up with errors that need the whole public to solve ?

 

Ya the glass solution you mention fixed the alpha... Not sure why I didnt catch that earlier.

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  • 2 weeks later...

Hey guys wanted to share how I fixed the issues on the baseboard. It was actually a geometry problem. I have to collapse my sweep modifier to Edit Poly and clear the smoothing. After I cleared the smoothing all my problems went away. Here is the final result...

View03_40_NE_DARK.jpg

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I have also noticed the alpha isn't working with transparency... for example... anything behind the glass that is solid is not actually rendered. See Attached...you can see the balcony outside, but the rails dont go behind the glass in the alpha.

ALPHA.jpg

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