Tinting Mass Effect diffuse textures for use in Garry's Mod

I suppose this isn’t really a modelling question per-say- but is closely tied to it, with textures/materials.

So, I want to try adding some additional NPC armor textures from Mass Effect 3 and 2 for some models that have already been ported into Garry’s Mod (Turian armor, in particular). However, as some people might know, the vast majority of NPC armor textures in the Mass Effect games are made from tint variations to a base file rather than having a number of other individual files. There is a base diffuse texture, then the normal/specular maps, and then one or two RGB tint files that color the armor a certain way- and also create skin tones and tattoos colors for aliens like the Turians and Asari and so on.

I already know how to find and export the texture files themselves as TGAs from the series’ PCC files. What I can’t figure out is what the best method is of tinting the diffuse textures with the tint files to create specific outfit colors like the ones you see in game, so I can then slap them on a model. I know some people have managed to pull it off for Mass Effect models that have already been ported; I’m hoping some of them may still be lurking and have some advice on this. What’s the best technique?

Assuming you mean tinting the textures externally, rather than in real-time in-game, the way I generally do it as such:

With both the diffuse texture and the color-mask texture loaded in your image-editor, I first insert the mask texture overtop the diffuse as a new layer. Then, I use the magic-wand with a decent tolerance to select all of one color (such as red) in the color-mask (Select Color Range may work as well). With all of the color selected, I then select the diffuse layer and promote the selection to a new layer - this will elevate only the selected regions of the diffuse to a new, separate layer. Because the selected region is the colored regions, this corresponds directly to the color-mask.

Once I have elevated all the color channels to their own layers, I hide the mask, and then select each layer and apply RGB tints / color adjustments as I see fit, until I finally get the color matching I want.

That’s how I do it, personally.

Been fooling around with it in photoshop and it’s definitely a workable method. Just requires some guess work and finangling.

I’ve seen some models ported to Garry’s Mod from Mass Effect with really accurate replications of the in-game tint combinations for npc outfits, so I just wonder how one gets it that close to the outfits presented in-game. I figure there must be information somewhere in the game files with the exact RGB coloration data, but as of yet I’ve been unable to crack that one- it has to do with UDK’s Material Instance Constant files I believe.