Texturing: How'd they make this diffuse map?
The image is a section of a diffuse map for a model of a tractor. Most of this detail is mapped onto flat surfaces as you'd expect for an in-game asset. Besides the reflectors, I don't understand how most of the detail for this diffuse map was generated. Especially the details of crevices and edges. I'm assuming it came from a high-poly model. However, the discussions and videos I'm finding of baking diffuse textures in Maya and Blender don't include any high-to-low poly process like I see for baking normal maps. It seems like there would be.
The closest thing I've just found is projections of high-poly details to a "remeshed" low-poly model in Zbrush, but even that only retained what appeared to be the height map, not the kind of combined lighting and height info applied to a diffuse texture. Or does this look hand painted? I'm not coming up with the right words to get search hits if this is a common process.
I'm just getting into modeling and trying to understand what a workflow would look like to update or create my own 3d assets/mods.
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Looks like a curvature map edited a little and overlayed over the top. Depending on when or where it's from it could also be some substance painter generator result that works with edges and crevices.
yep looks like some kind of "edge" render to texture overlay if edge angle is greater than 180 you render light and if less render dark. Back in the day in max you could use vertex shading script "pits and peaks" then render to texture that, IIRC there were a couple of free plugins to do the same thing (without going through the vertex coloring) though as i remember they require a lot of post processing. And before that you would paint on the texture save and check the results on the model using a uv layout render as a guide.
Thanks for the ideas, using your terms gives me way more discussions to look through. If it matters the game came out late in 2014, same year substance painter came out.
If I'm understanding your curvature overlay idea I might I found an example here that I'd be able to use in blender
I also looked into Substance and it has a "bake lighting stylized" filter that looks like it'll do the same thing as long as it'll work with the details from the normal on the low-poly. Otherwise I'll have to sort out how that works in substance. I had found a video on this site but it got removed over the weekend apparently.
You'll find plenty or ressources about baking curvature maps from high to low, as this is one of the very essential passes used for texturing and pretty much every baker supports it. There are also ways to such data directly from a normal map (since in many cases it contains all the needed slope information), either with dedicated tools or Photoshop.
However you might want to keep in mind that you might be blindsinded by assuming that the game you want to mod used that workflow in the first place. I would say that it is actually quite unlikely (but not impossible of course) for a tractor game from 2014 to even use a full-on high to low workflow, in the way it is usually done these days at least. At best it is probably using some clever trickery (typically done in 3DSMax as it has the best toolset for that, probably follows by Blender) to generate a "pseudo high" model directly from a lowpoly model. And the edge detection could be done in all kind of ways from there, like in the video about with the Pointiness output.
Now of course the beauty of modding is that you can use a much more recent workflow than the one originally used by the art team, or spending much longer on an assets thanks to not having production deadlines. So from there the sky is the limit.
If anything just knowing the name of the game and seing a few screenshots would allow people to answer your question much more precisely than merely looking at one single texture.
Personally I'd lean towards this, as this doesn't involve any highpoly modeling at all - just manipulations on a good old lowpoly model and nothiing else.
- Lowpoly model with hard edges
- bevel node to generate smooth antialiased edges
- baked to OS normalmap to store this edge information
- hard edges removed from low, so that a TS map can catch them
- baked down to TS normalmap for final game use
And from there the resulting normalmap is this, which can then be converted to a curvature map using a photoshop script, or Xnormal, or good old CrazyBump, or any more modern equivalent and most of the concave and convex edges will show (I missed one marked edges at the bottom right, that's my mistake :D)
Of course there's no way to know if this is what was used in the game in question, but this gives you smooth "highpoly like" edges, and the curvature map. A very quick way to fake a high-end look for hard surface assets imho.
This has been possible for a long time even without the bevel node BTW, as one can just bake the OS map, blur it a bit, then convert back to TS with near identical results.