easy spec map generation.
polycounter lvl 12
I know What a spec map does, but is there a good way to generate a spec map that I can work off of into a custom spec map. Is there a good tutorial beside the one here at polycount about specular maps. Thanks!
Replies
do you use any tools like ndo2?
That being said, I usually derive it from my colour map. I start by using adjustment layers, so it's non-destructive. But like I said, it takes a lot more than that, but it'll get you to a good starting point.
I pretty much make my diffuse, then duplicate that folder and start messing with layers to make the spec.
I like my spec to be higher contrast, and have much stronger edge highlighting + surface detail.
Dielectric materials should be the opposite color in specular as their diffuse.
Conductor materials should be the same - or more intense - color.
Glossiness is as important as Specularity. The right spec with the wrong gloss will look completely off. A lot of people get away with using a single value of glossiness for their entire model, but a gloss map can make things look that much better.
You can get some cool effects by making something subtle in the diffuse, but super contrasty in the specular. Or making something dark in the diffuse, but giving it a bright specular color.
Which texture is important depends a lot on what material you are working with. For something like cotton cloth, diffuse and normal are way more important than specular. For metal, specular/gloss can be as imporant as diffuse. For something like glass, or oil, specular is pretty much the most important texture. Figure out what textures are most important for your material, and spend the majority of your time getting those to look correct.
Just remember, as the author said, not to blindly follow what is written, especially when engines are involved. Most engines right now take the Gamma Correction into account during texture import, so what used to be the 'common' rule of 'Make your characters skin specular blue' isn't true anymore, and you can (and should) apply an almost white specular map to your character, if anything, with a calibrated engine, you specular is actually going to look pretty dulled out and next to non-existent with an inverted color.
Also, I have seen a great deal of rubber materials, like those of heavy duty scissors which when taken a picture of with filter on your camera, you'll actually see their specular-property is inverted as well, and yet their whole point is to not channel any current.
Also, about the cotton cloth not really have as much importance in terms of specularity as other materials, that's REALLY situational. Most cotton (especially non-natural cotton) will have Anistropic highlights on the strands, and while you won't see them head-on, it will be apparent at reflective angles (see Schlicks formula), so there is that to consider as well.
Then there is the entire mess of dealing with cloth specific sub-clothes, like Velvet and etc, which are an entire mess of their own.
As to OP, I suggest to first taking a look at what engine you're going to be using. I suggest taking some time and playing around with basic models and try to see what parameters do what and how they function to get a feel for it, because pending on your engine, you can say 'fuck that' to almost about everything in this thread, and just stick a B&W version of your Diffuse map to your model as spec and call it a day.
As to how to generate them? There are many ways, and almost all of them involve your Cavity Map at one point or another alongside your Normals +RG and -RG channels with a touch of Diffuse, but since you have nDO, that should give the results you need faster and with less layer hassle.
Thanks for the info about gamma corrected specular stuff! I'm surprised I haven't run into that info before.
It's more than a little confusing when pretty much all tutorials still tell you to make skin specular blue, and most of the people here on polycount still do (if they color their spec at all).
when texturing you should really be working on all your maps at the same time, focusing on making a good, easily readable material rather than trying to complete the diffuse first and shoehorning in specular. with some practice you start using less layers and in general do cleaner work that reads better with more contrast in less time.
I think most of the people who really know their stuff can't be assed to explain it to the rest of us, most of the time. So when someone takes the time to explain it in a way that makes sense, we tend to latch on to that...whether or not the info is outdated.
Most people just need to test and experiment on there own to figure things like this out or prove them right or wrong.
I would only do that if said person sharing the information makes shit look cool - investigate before accepting it. Talk is cheap and lots of stuff is said by people who even if they know *exactly* how something is supposed to work have no work to proove they can apply it - which is a big problem.
I want information that comes from people who know wtf they are talking about, and can apply it because it shows in their work ie Earthquakes recent thread on normal maps & material definition etc.
OP - Totally agree with Perna - spec is super important, dont skimp on it man! in most cases its the most important map. Material definition is key, and it does more for material definition than the color in general. It's also where a lot of people fall down - desaturating color map = spec map - done :poly142:
Polycount never lets me down!