When applying Specular maps in Photoshop
polycounter lvl 6
Hi all,
So this will probably be a very quick question. I'm an aspiring Environment Artist and I wanted to ask about using Specular maps in Photoshop. When you apply a Specular Map in Photoshop to your Diffuse map, and then when you import it into UDK, should you use the Diffuse map texture for the Specular port in the Material editor, or should you use the actual Specular map itself separately?
Information on this would be greatly appreciated. Thank you
So this will probably be a very quick question. I'm an aspiring Environment Artist and I wanted to ask about using Specular maps in Photoshop. When you apply a Specular Map in Photoshop to your Diffuse map, and then when you import it into UDK, should you use the Diffuse map texture for the Specular port in the Material editor, or should you use the actual Specular map itself separately?
Information on this would be greatly appreciated. Thank you
Replies
Typically you load the Specular map into the Specular slot since an authored Specular map will look different than the Diffuse map.
Also just to confirm, are you using UDK(Unreal Development Kit) or Unreal 4?
However you may be referring to storing the specular map in the Alpha channel. If so, yes that's a valid method. Except that this will reduce your specular to grayscale, you will have to add color via the material, which will limit it to being the same specular color across the whole material.
In case you haven't seen it, Brief Considerations About Materials by Pedro Toledo is a great explanation of how specular works.
Eric: Do you mean you apply the Specular Map in the Specular slot of the shader in Maya, or do you mean within UDK? The way I did it was that I put the Specular Map at the top of the layers in Photoshop and set it to the Overlay mode at around 45-50% Fill. I don't think I did the Alpha channel part for the Specular since I never touched the Alpha channel.
Yes, applying the specular map means hooking it up to the slot in the material editor.
That can be overlayed on the diffuse, and it adds a lot of extra depth to your texture.
But, if it's an authored specular map, it shouldn't be overlayed on the diffuse, and it should be plugged into the specular input in UDK.
Can I still use the Curvature map created from Crazybump as a Specular Map, or create my Specular Maps a different way?
I don't think you understand what a specular map is. Let's start there.
Your diffuse map and specular map will always be seperate. You rarely, if ever, overlay a spec map on your diffuse map.
Spec maps are applied in engine as a seperate texture that controls intensity and other info(sometimes) of light reflection.
Spec maps from crazybump are not specular maps. They are poor auto-generated textures that have very limited use, but shouldn't be used as actual spec maps. Spec maps need to be thoughtfully created to properly sell a surface.
Are you following a tutorial? There are plenty to be found that can go over the basics of this in a more focused manner.