issue with projecting textures onto overlapping geometries

Hi,

I am facing an issue when projecting different images onto overlapping geometries in order to separate the diffuse and reflection contribution of lighting.
I project a low-rez diffuse convolved spherical image onto a simple room geometry, and project a higher-rez spherical image onto the duplicated room geometry. And then set up two vrayobjectproperties for each room geometry so that a room geometry will contribute GI only and the other will contribute reflection only.

In the rendered image, I see checker board type of pattern shown on all walls of the room. If I hide either one of the room geometry, the checker board type of pattern is gone but then I lost either the GI or reflection contribution to the CG objects placed within the room.

Any idea or workaround?

Duplicated geometry won’t work. It would be better to use material override attributes with different materials for GI and for reflections.

Best regards,
Vlado

Vlado, can you be more specific on how to use material override for this purpose, if intend to render the scene in one render layer. Say I only have one room geometry in the scene now, how can I apply two materials (each has its corresponding spherical image attached) onto the same geometry via material override? I can only think of using material override through multiple render layers.

Hey Vlado,
I found the Vray material override tab. However, as I plug a diffuse material to the GI override with it enabled, the render appears the same as the one that everything is sampled with high-rez spherical image?

I am using the stable build 2.004.

I meant the addition V-Ray material override attributes as described here: Chaos: Industry-leading design and visualization software

Is this what you are using?

Best regards,
Vlado

Yes, this is exactly what I am using. I tried simply plugging in a VRay matreial with solid pink color as extra GI override for the material I used for reflection. But I didn’t see the pink GI effect on my diffuse objects in the scene.

Works for me on a simple test… it’s a stupid question, but do you have GI enabled?

Best regards,
Vlado

Yes, I do have the GI enabled.

In that case, it would be best if you can get us the scene to vraymaya@chaosgroup.com and we will look at it - I’m not quite sure what’s your setup.

Best regards,
Vlado

Is there anything to do with the fact that I am using Vray light mtl for projecting spherical image onto?

That should be alright, I think… but I really need to look at the scene to be sure.

Best regards,
Vlado

I just send a sample scene to you and vraymaya@chaosgroup.com. Please replace the spherical image with any one of yours or simply some other texture.

Thanks.

We reproduced the issue and forwarded it to the developers.
For now as a workaround create one VRayBlendMtl set the LightMtl in the Base slot.
Apply the VRayBlendMtl to the box.
Enable VRay Overrides for the LightMtl and set a another VRayLigthMtl (with a red color) in the GI slot.

Thank you for the feedback.

Thanks Zdravko for the quick reply. The workaround worked. Look forward to seeing this issue being resolved in a future build.

Hopefully this should be fixed in the next nightly.