issue with projecting textures onto overlapping geometries

[jasonhuang1115]

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?

[vlado]

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

[jasonhuang1115]

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.

[jasonhuang1115]

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.

[vlado]

I meant the addition V-Ray material override attributes as described here: http://www.spot3d.com/vray/help/maya...b.htm#Override

Is this what you are using?

Best regards,
Vlado

[jasonhuang1115]

I meant the addition V-Ray material override attributes as described here: http://www.spot3d.com/vray/help/maya...b.htm#Override

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.

[vlado]

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

Best regards,
Vlado

[jasonhuang1115]

Yes, I do have the GI enabled.

[vlado]

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

[jasonhuang1115]

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

[vlado]

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

Best regards,
Vlado

[jasonhuang1115]

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.

[Zdravko]

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.

[jasonhuang1115]

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

[ivaylo.ivanov]

Hopefully this should be fixed in the next nightly.