Page 1 of 1

Faking the GI

Posted: Wed Mar 03, 2010 5:31 pm
by Bigguns
Hi all,

Here is a little trick to fake GI, it consist of using and light(you must place the light at the exact same place that the camera is) and uncheck specular on the light and exclude the mesh of the sclap on both lighting and shadow, put that light at little multiplier. IT's not 100 % like true gi, but does a good fake.

So here is the result.

Re: Faking the GI

Posted: Wed Mar 03, 2010 5:53 pm
by cem
The problem with hair and GI is that hair does not *block* GI. However, it receives GI illumination. As a result hair gets illuminated a little too much especially at the roots. You can easily fake this effect for short hair by using a gradient map for making hair roots darker.

Re: Faking the GI

Posted: Wed Mar 03, 2010 5:59 pm
by Bigguns
ho yeah great tips Cem thank, I will try it.

For now, I did a test with shadow in pass, I get a pass of the shadow with not gi (this one is at 100% in the layer of photoshop) and an other pass of the shadow pass but this time with Gi faked, and I put this one on top of the other layer in photoshop at intensiti of 50% and on top of it, the hair with the faked GI on it, I get a great result.

At the right it's without the trick just the faked gi, a direct output and at the left with the trick I explaiend.

Re: Faking the GI

Posted: Thu Mar 04, 2010 6:53 am
by 3DTutorial
Nice technique, thanks for sharing.

Kind Regards,

Joe