Glossiness and specular

Graphics and GPU Programming Programming

Started by Aqua Costa August 08, 2011 01:59 AM

2 comments, last by Aqua Costa 12 years, 8 months ago

3,705

Author

August 08, 2011 01:59 AM

What is the relation between specular light and glossiness of a material?

I see in presentations that games often store glossiness and specular of material and use both to lighting equation... However I don't really understand it...

Also, all objects I use in my projects have specular maps should they also have glossiness maps?

CryZe

773

August 08, 2011 02:03 AM

The specularity value is the attenuation factor of the specular reflection. The glossiness value describes how "sharp" or "blurry" the specular reflection is. It's also known as the specular exponent. This is how it would look like in the specular part of the Blinn-Phong model:

specularFactor * (N.H)^glossiness

Hodgman

52,717

August 08, 2011 02:12 AM

In CryZe's post above, the "specularFactor" is sometimes also called the "spec mask" or "gloss mask", and "glossiness" is sometimes called "spec power".

Yay for unified terminology