Prevent VrayLightMtl from generating GI

[davision]

I like to use the VrayLightMtl to create self-illuminated objects (like street lights or headlight faces) but I don't necessarily want the vraylightmtl to actually generate light for GI (since I have a regular light or Vraylight to cover that). I'd like to be able to turn off Generate GI within the material itself, so I don't have to manually turn off objects throughout the scene (which is also problematic when using Multi-mats since I might only want a portion of an object 'turned off').

[dlparisi]

I too would like a "turn off GI" checkbox for the lightMTL but you can easily acheive the same thing by just wrapping it in a VrayMtlWrapper material and uncheck "Generate GI" and Receive GI". I do it all the time.

[davision]

Thanks for that tip. I forgot all about the wrapper. Haven't used it in years. (Still my request stands, please, Vlado.)

[nils_p]

+1
It saves a bit of time setting up the material with the wrapper.

[berglte]

This feature seems to be broken with vray 2. Using LightMtl inside MtlWrapper doesn´t produce any light at all, but the object can still be seen in reflections. Unchecking "generate GI" from objects vray properties on the other hand works fine as expected.

[super gnu]

turning off "generate GI" shouldnt have any effect at all on reflections, as they are not related to GI (or any kind of light emission) in vray. if you dont want the material to show up in reflections, you can turn off "visible to reflections" in the object settings, or use the vray override material, putting a transparent material in the "reflection material" slot.

[vlado]

This feature seems to be broken with vray 2. Using LightMtl inside MtlWrapper doesn´t produce any light at all, but the object can still be seen in reflections. Unchecking "generate GI" from objects vray properties on the other hand works fine as expected.

There haven't been any changes in this regard for V-Ray 2.0. The VRayLightMtl only emits direct light when it is the only material applied on an object - this feature will not work in warppers, multi/sub-object, blend materials and so on - this was the case for V-Ray 1.5 as well.

Best regards,
Vlado