View Full Version : Doubt on V-Ray GI (how to render with out geometry dome)

08 August 2011, 05:27 PM
Hi all!
Im stuck with this last "movement".. I know I saw it somewhere but I dont remember where or how!
So here's the question:

I havee my scene rendering with V-Ray and GI, I'm using a cube surrounding my scene to get GI to bounce and work like I want.
Now I need to render the image using/keeping the GI ilumination but I dont want the cube wall's to be rendered ( I would like to have the background "empty", "black").

Any ideas? What do I need to activate? Or do..?

Thank you so much in advance.

08 August 2011, 02:14 AM
I think either set the 'primary visibility' to off in the cube's attributes, under renderstats.
Or for more options, assign a VRayMtlWrapper material to the cube (with your current material plugged into the base material slot) and set 'Alpha Contributrion' to -1.


08 August 2011, 09:22 AM
Hi David!
Thank you for your reply! :)

The primary visibity option was my first try, but V Ray simply ignores it.

I did try your second sugestion, using the mtl wrapper material, but it did not work either..!

Well, I'll look around a little more to see if I find a solution.

Thank you for your suggestions!

08 August 2011, 11:09 AM
Maybe you should post a scene.
Primary visibility works perfectly well for me. The object continues to generate GI and is invisible in the scene.
Alternatively, assigning a VRayMtlWrapper with matte surface checked and alpha contribution to -1 has much the same effect as the primary vis method, but has the added ability to catch shadows and reflections if you choose to enable them.

Are you sure you dont have something mapped to the global GI slots in render settings or a camera image plane, or even other objects outside your cube?


08 August 2011, 06:12 AM
Djx, just saw your post..!

Hummm well, I'll try again as soon as I get home. I'm quite sure I have my scene alright, but I'll check it again to see if something is going wrong..
Because besides this, yesterday I had problems to get the render elements to render.. (They were all in black with no info).
Maybe I just have my scene corrupted.. because it's the first this happens to me.

Either way, I got the render I wanted with some turn around solution

I'l try your suggestions in a new and clean scene and post the results later!

Thank you very much djx!! ;)

08 August 2011, 03:52 PM
Ey David!
Both of your solutions worked fine for me!! :)

Want I dont know is why in that particular scene they dont.. oh well!

Thanks, the material wrapper solution is very very cool!!

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08 August 2011, 03:52 PM
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