Gi bypass

[kwamecode]

Hi, is there a way to bypass an object from receiving gi... As you can see on the attachement pic, the model's teeth are getting red gi color from the lips, as well as too much occlusion.
I tried the CoronaRaySwitch material, but I could only stop the head from emitting, and it rendered black with SSS activated.
Thanks for any help.

[mferster]

There isn't a way to change how an object receives GI only how it casts GI

You can try a few things....

1. put your lip/skin material in a corona ray switch material and make a version with a neutral black/grey/white lip color in the global illumination slot.

2. you can trying adding a white/grey plane in the mouth between the teeth and lips and then in its object properties turn off visible to camera

3.  desaturate in photoshop

[mferster]

also in this situation you can try using a front-back map in your diffuse. assuming its a stationary camera, from your camera view select all the mouth faces > invert your selection > flip the normals of the inverted selection. assign a neutral color to the back face side map.

[Njen]

I'd be curious to know if your shaders are set up physically accurate. To help check this, place two spheres in the mouth near the teeth, make one white diffuse, and the other 0.18 grey diffuse, and set both glossiness to 0.3.  Then depending on the result of the colours of the spheres, you can accurately  gauge whether your material properties need updating (reflection, SSS, etc.), or if you really do need to cheat.

I say this because I know that Corona can simulate this type of scene physically accurately (I am doing something similar myself), so maybe before you start cheating, you should confirm if your setup is behaving properly.

[TomG]

It does look more like reflection to me than GI, so the tests Njen suggests would be ideal to find out for sure.