Hand Painting Obsidian Texture in Photoshop. NEED HELP

Daven

Alright, I'll back it up a bit. For our game production class I had to texture one of the weapons this week.



It's supposed to be a multi-purpose tool meant for climbing, trapping animals, whatever. Right now I'm trying to paint the blade to look more like obsidian rock instead of a dark metal. As well as adjusting the specular map to include more blues, greens, and purples, and adding a gloss map, I need help making the normals look more, well, like obsidian. So far I've had no success. Here's some quick reference I picked off of google.

Any help or critique would be great.





Thanks a bunch.

Deady

It looks like you're off to a good start. There is however one major difference between your model and your reference. The blade is polished, almost completely smooth, and the cracks/forms it does have are very soft and rounded. Compare that to the chipping and very sharp edges that are present in your reference. It's not something you're going to be able to do very easily with diffuse and spec. For the best results you'll probably want to sculpt it for a normal map.

BoBo_the_seal

Heh I didn't read all of your post before doing a quick painting. Oh well this might not be what you are looking for



I thought you were asking how to do it as a hand painted texture. I didn't realize you had a normal and spec.

To truly pull off Obsidian, you have put a lot of love in the spec map and be more subtle in the diffuse map. Actually doing a spec similar to how I painted it above will start you along the right direction. Just blow it out a lot more and have a dark diffuse map that only has subtle shading.

- BoBo

killnpc

I'd start with the larger shapes sculpted out.

Then overlay the stepping and dings using CrazyBump or whatever.

I did something like this one for this one texture.


Save out an image as a gif with limited colors. Use "Save for Web" in Photoshop. This used 8 colors. It's a bit different than running a cut-out filter.

I run that image through CrazyBump and stuff.

iniside

Obsidian is purly black stone. Most of it definition going to specular maps, as that stone is very shiny even if you look at it at night.

nfrrtycmplx

Obsidian is highly refractive (i think that's right)... you'll want to either use a cube map to get the colour variation or use a brdf shader (i'd use a cube map against the normal map)

helpful thread
http://www.polycount.com/forum/showthread.php?t=49920

as for the normal map, you may do something like taking a bunch of random cubes/rectangles, putting them together in zbrush along with some elongated cubes that are bent into curves... composite them in photoshop and blammo... obsidian.

good luck

Daven

Wow, holy crap. I didn't expect a response back this quickly. Thanks a lot guys.

Deady - I'll put more sharp edges in and see how it turns out. Before I had just slapped a few custom brushes overtop just to see how it'd look lol.

BoBo - Wow, that is wonderful. That will actually really help when doing the spec values. Thanks man

killnpc - I've never tried that approach before. I'll give it a shot.

iniside - yeah, i'll fiddle with the specular highlights and see that I get.

nfrrtycmplx - I'm hoping I can just get away with a gloss map for this one, but if I need to do a reflection map it shouldn't be too hard to compensate. Zbrush might honestly be easier at this point so I can give that a shot as well.

nfrrtycmplx

having done a bunch of materials work specifically for this look, I can tell you on the real that a simple gloss map will look like bullshit...

you gotta really look at the properties of what you're trying to mimic... not on the ineternet but in your hands and move it around in the light...

anyone who's seen obsidian will look at your thing and be like , "woah, nice plastic hose...

if it's not supposed to reflect and refract light then something bobo has put up is probably one of your better options...

if you ever find yourself thinking, "i can just get away with..." while doing anything, you should reconsider your approach. cause if not, people looking at your portfolio will be like, "I could get away with not hiring this guy"

good luck

Daven

Hahaha, that's true. I'm not trying to cop out or anything, it's just trying to find the best way to do it is all. This isn't porfolio worthy anyway

nfrrtycmplx

i hear yah bro, but you have to ask yourself the question: if it's not portfolio worthy, why do it at all?

every piece you do should be portfolio worthy, otherwise you're wasting your time IMO. I think that's one of the biggest mistakes artists/"artists" can make when going to school... doing the exercises and going through the motions with no expectation of ever putting the stuff in their portfolio...

sure you'll find yourself tossing most of the shit you do... I've been doing this for a while now, and have very little stuff in my portfolio, despite the fact that I've worked on several games already. But never once did I go into a modeling/texture job thinking, "this isn't going to be worth showing anyone"... because then how can I expect anyone to pay me for it? right?

Just some food for thought.

Daven

I'm not considering this wasted or trash, I'm just saying that it wouldn't be a front showpiece. Regardless of how it turns out, it's more about what I learn from the experience if anything.

___

Alright, here's some revisions. I think I got it a little closer to what Bo Bo had. It may need a little more love though. Tell me what you think

gilesruscoe

hit the spec map up with a bit more brightness, obsidian is very shiny! i'd say youv'e got the colours right tough.

nfrrtycmplx

looks a bit soft atm. could punch up the colours of the spec with saturation and add some more hue shifts.

would be interesting to see your normal normal map... the edges of the blade look soft for obsidian or something obsidian like

mucho bettero though than what you started with

BoBo_the_seal

You are heading in the right direction! Looks a lot better. As mentioned, it's a little soft. Work on making it a bit crisper.

Oh, and you might want to fake a little highlight work in the diff on the central ridge. It's an element that you want to pop from all angles and lighting.

- BoBo

jeremiah_bigley

Nice man! It has come a long way! I would love to see the textures on it to see how you went about it in the end. I do think you need to work on the handle now... the handle feels really flat and fake.

Daven

Yeah, looking at it now it seems like a bit of the handle detail is wasted, or rather i'm eliminating the normals in the diffuse. Here's my texture maps. 1024x1024 for all of them.

Oh yeah, and I did all of the normal work by painting a height map and then using nDo.

Diffuse


Specular


Normal


Height

crazyfingers

Comin' along great dude. I think the weak point thus far is the height map on the blade, it's a bit flat, could use more gradients to get the normal popin. When you think of obsidian you think of something a bit more chiseled, with lots of geometric flat areas here and there with some cool organic ridges mixed it, right now it's just too flat. Really nail that height map, make it interesting, then you can use overlays in photoshop to increase the power of the normal in specific areas. It also helps to use separate overlays with Gaussian blurs used and then normal mapped. On top of this you can change the sample size of the xnormal generation. By using several overlays you can really fine tune a 2d normal map.

Once you have a more diversified normal (shouldn't look like a flat blue throughout most of the blade, I'd be looking for nice geometric areas of other colors) I think you can lower the gloss and let the spec really shine through to give some awesome highlights without overblowing the whole blade.

1 last thing, it'd be nice to see some hints of red in there too, i'm just looking at the below reference bobo linked. Hawt stuff.

Anyway, keep it up man, this is looking pro already just gonna get better.

Daven

Alright, well while I'm finishing up those textures, I might as well post the next item in my line-up; a ceremonial dagger. Mostly used in sacrificial rituals, it'll be found inside one of the abandoned temples on the altar. Such a pretty thing to leave lying about.

I had pretty much total freedom with this thing, so I had some fun with it. The core and blade are obsidian rock with silver and platinum detailing for some flair. The red orb at the bottom is blood from the enemy godess.

Urthrese

try applying this and see what you think





i did this in like 15 minutes but it should help get the point. i think you need to refine your maps. they have base colors laid down but no lighting information and no sharpness to them. there aren't any crisp details at the moment. you have the groundwork but now is the hard part of refining the details.

Daven

oh damn. thanks a lot. I tried a quick apply and comparison between the two maps and it made a big difference (well, disregarding the jpeg grain lol). Shouldn't be too hard to fix my originals.

Urthrese

cool, that was just a quick paintover so i can render out any area you need help with to show you an example and then you can just mimic it. just keep painting and if you find you need some more help just post again or send me a personal message or something.

i hand paint textures all day so it doesn't take me long now. those normals were also hand painted in so if you need help with that too just let me know.

Urthrese

also that paintover bobo the seal did down there, you should paint that EXACTLY how you see it there in the texture. hand painted objects can have normals and spec just like everything else but you still need to render out all the lighting and detail information. your diffuse should be your strongest map out of all of them. they should all work together but your normal map, spec, etc... and shaders should all help make your diffuse look better.

nfrrtycmplx

Diffuse = midtones
Specular = highlights
Normal = shadows

that's generally the way I look at it... it's more complicated than that of course, but... yeah.

diffuse is the natural color of the surface if everything was evenly lit... most everything should be in the same or similar value as to not compete with the lighting of the scene or light/dark information generated by the normal maps

the spec is the color modulated against the light reflected from the scene. This means if you have a white light and a blue spec map, the specular highlight will be blue...

RGB values comin at you
spec map (pixel) x light color = highlight result

XY = Z

if X = .8, .5, 0
and Y = 5, 3, 3 (this is the result of the rgb color of the light multiplied by the brightness)

then Z = 4, 1.5, 0

This means this pixel will be blown out to some kind of orange highlight... (if you have some kind of post fx on... otherwise it's just going to be a bullshit looking white pixel or depending on the renderer... clamped to 1, 1, 0 which is yellow, i think...)

anyway, the point being that the normal map and the spec maps are not in service to the diffuse, but rather, they all help each other...

your normal map is a representation of your high polygon model... those details you used to have to paint in to the model to get the depth and form you wanted, no longer have to be in the diffuse. They should be suggested... and depending on the "art direction" you could make the shadows a completely different color... or wahtever...

There are no rules really, as long as the shit looks good. But fully understand the relationships between the different maps and you will be able to come up with some pretty awesome effects...

for instance, you could get away with having only a normal map on as a texture lookup in a shader and get the diffuse by (in udk) running the same normal map through a fresnel and using that output to interpolate between differnt rgb values... making it so that the diffuse is then serving to make the normal map look better... it all depends on your art direction.

I only mention it because i find it wicked interesting and maybe to give you a few ideas...

cheers