Converting Rough/Metal to Spec/Gloss

fullchaos13

So I just picked up Bitmap2Material 3.0 and I'm totally loving the software. The biggest problem I have is, I'm trying to create PBR ready textures for use inside of dDo and when I create them inside of Bitmap2Material and export them out I only get roughness/metalness and not spec/gloss which I need in order to import a custom material inside of dDo. So I was wondering if there was a way in which I can convert my roughness maps into spec/gloss maps.

passerby

http://www.marmoset.co/toolbag/learn/pbr-conversion

fullchaos13

passerby wrote: »

http://www.marmoset.co/toolbag/learn/pbr-conversion

Sweet thanks for link it was a great read. I got a few quick questions though if you don't mind.


Since I'm trying to create a tilable stone texture I imagine I would skip that first top half because I have no metal information?

In the second bottom half he creates a gray fill layer (#383838), would I use the same value, or does that value depend on the real world specular value of my material? Also since my stone texture has lots of different colors/values in the albedo, the specular map for rock cannot be a monotone color, so would I multiply the two layers together to get an accurate result?

Also what about my roughness map? The tutorial doesn't seem to say anything about using the roughness map to create the spec/gloss.

P.S. I'm a Photoshop nooby :P

billymcguffin

Just invert the roughness map to get the gloss (although make sure it's in linear color space first). Most dielectric materials have very uniform spec values, so actually the spec will likely just be a flat dark grey (this is what a metalness shader will use for the spec anyway if you plugged in your albedo, metalness, and roughness)

fullchaos13

billymcguffin wrote: »

Just invert the roughness map to get the gloss (although make sure it's in linear color space first). Most dielectric materials have very uniform spec values, so actually the spec will likely just be a flat dark grey (this is what a metalness shader will use for the spec anyway if you plugged in your albedo, metalness, and roughness)

Alright so creating the gloss map seems easy enough, just invert the roughness map, although I didn't understand what you meant by linear color space? Do you mean that the gloss map should only have gray values?

Also by dielectric materials you mean metals right? Well the texture I'm trying to make isn't a metal, its stone.

Anyways I decided to post a few pictures of the textures so my message is easier to convey. I apologize in advance for the terrible photo editing skills haha .

These are all the maps that I extracted from Bitmap2Material:



This is the new Gloss map I made by inverting the colors on my roughness map:



All that's left now is to create the Specular map, which I'm still confused on how to go about doing that.