How do I combine Specular Maps with Normal Maps?

[Nephelus]

Not sure if Specular map is the term Fallout uses. I mean the mapping that describes how light reflect off an object. Without one, objects are very shiny by default.

 

If I have a Normal Map and a Specular Map that are 2 separate images, how do I combine them properly?

 

I know that the Specular Map has to be the Alpha Channel on the Normal map, but I don't exactly know how to make this happen.

 

I'm using Paint.net because it has built in support for .DDS files but I don't see any way to modify or add anything related to Alpha. Is there a better program I should be using?

 

If somebody could give me a rundown of the steps I need to follow, I would really appreciate it.

[imu333]

Not sure about Paint.net.

 

Fallout combines normal and specular maps into one, the specular in the alpha channel. (®ed(G)reen(B)lue(A)lpha)

 

Easiest way is using Photoshop, pasting the specular into the alpha channel and exporting using Nvidias DDS plugin

 

Though if you don't have Photoshop, you can use GIMP.

The DDS exporter for GIMP is not as good as Nvidias so it may produce artifacts.

So I recommend that you add the alpha channel in GIMP, export it as a .tga file and then convert it to a .dds using Nvidias command line tool.

 

EDIT: Can provide download links and further instructions if you need. :)

Edited April 9, 2015 by imu333

[Nephelus]

I've got the plugin installed in CS2 (which is free BTW). Can you tell me what the export settings should be once I go to save the combined image? (Assuming they are the same for whatever version you are doing.)

 

I've been told to use DTX5 before and I think I want MIP maps but that's all I really know about.

 

http://i.imgur.com/fmj5Y3e.png

[Nephelus]

Everything is working great! I just left everything else as default settings and I've got no problems! Now my models don't look like plastic anymore (except where they are supposed to) Thanks for your help.

 

I'd still like to know how it can be done in Paint.net because, if I make a tutorial series, I'd like it to use simpler tools to make it more accessible.

[imu333]

Everything is working great! I just left everything else as default settings and I've got no problems! Now my models don't look like plastic anymore (except where they are supposed to) Thanks for your help.

 

I'd still like to know how it can be done in Paint.net because, if I make a tutorial series, I'd like it to use simpler tools to make it more accessible.

 

Use this plugin: http://forums.getpaint.net/index.php?showtopic=1854

Open your normal map and go to Effects > Alpha Mask > select your specular map > save .dds as DXT5 (or A8R8G8B8 for no compression), generate Mip Maps