Dark semitransparent object with GI

[apu]

Hi, if I render an object that is semitransparent, like oil, and turn on GI, it renders really dark. I'm using Adaptive sky map with a HDRI, and it looks like petroleum instead of oil!!!!.

Are there any tricks when it comes to render transparent objects using GI?

Thanks!!!!

[Arketype]

Hi Apu.

You need "secondary illumination" in your scene. Any raytraced transparency or reflection cannot use the "primary" GI rays cast for basic shading.

So basically your transparent object (and what you see through it) is not being illuminated.

There are 3 methods of doing this.

1) Add secondary rays in the GI dialog (brute force method -Very Slow).

2) Add standard lights with their mode set to "secondary" (very fast "phong" shading, but secondary illumination will not have the "GI look")

3) Use lights with photons set to "GI & Secondary" . This can give very high quality throughout the image with highly realistic shading for both "primary" and "secondary" points.

Dave

[apu]

Thank you!!!, I'll try that!!!