Car: Hints on refining my textures?
BIG version Edit: Arhg! Photobucket resized my picture.
Hey guys. Guess it's a fish car. I have to refine the texture on this car by next friday. One of the several things I need to work on through thanksgiving.
I'm mainly thinking about doing some subtle highlighting, only got some ambient occlusion baked in right now. Need to define the roof of the car more. What do you guys think?
Replies
pliang: I think I'll just trow a transparent material on it.
Some hard specular highlights would help bring out some of the forms a lot, the chrome could use some color/variation too.
The line-work on the door/trunk/hood could use some hand-painted shading to bring them out and make them look a little more 3D.
Honestly right now I'm digging the 'Crazy Taxi' style of the car, I hope you don't push it too far away from this feel, but thats just me thinking out loud.
Zephir: Well, I was only thinking about doing the diffuse map. I haven't done specular maps and normal maps before. And I don't know if our teacher wants us to do it. :S It's all about doing the no-render realtime thing. Maybe I'll give it a shot though.
pliang: I think I'll just trow a transparent material on it.
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If your teacher will allow it, get an environment map on that. Environment maps are very lite on the cpu when dealing with realtime assets and it does wonders for giving the illusion for reflection to helps break up the silhouettes and have a more believable material.
it's all about doing the no-render realtime thing
[/ QUOTE ]Those are specifically for real time, they are quick hacks aimed at mimicking the longer, more CPU intensive rendering methods. A spec map is a standard weapon in the industries arsenal. If you're learning real time techniques, you'll need to learn spec maps at some point, better get started sooner rather than later.
It's not as scary as you might think. Specularity is a big word for shine. It's a fast way of faking the reflection of light. A spec map is really just a mask for that shinny highlight. Kind of like how you can use an opacity mask to make grass, you use a spec map to mask out shinny areas. Being able to define where you do and don't want the shine is important, otherwise it looks like someone coated your car in plastic. Spec is important in car paint, very important. We could be here for years if I got started on car paint shaders and rendering settings.
With a spec map you paint white the areas you want really shinny and black the areas you don't, using shades of gray for things of different shininess. So for example the main body of the car might be almost white, a grey color, and the body lines would be black because you don't want shine in the deep shadowy parts. You want to break up the shine and not have it cross over the body lines.
Left has no spec map and the spec is running right over the body line.
Right has a simple B/W spec map.
Notice the white blurred lines on the spec map and what it is doing to the shine on the sphere. Doing this helps push the shininess on those folded metal edges just a tiny bit. Which will help define the body panels more.
You can use a colored spec map which is almost the same as its B/W cousin but it also defines the color of the shine. So you could set the color of the shine to be a natural sky blue toward the top of the car (faking the sky) and a black/brown toward the bottom (faking the ground). This would help the specular color fake the reflection of the world around the car, and you might not need an environmental reflection map if your spec map is adjusted correctly. It's not a perfect fix for faking actual reflections but environmental maps can't be applied to every last little thing that has shine so faking it with a good spec map becomes important. Since you have a slightly cartoon look going already *and env maps are approached differently in almost every engine, I would stick with spec/color for now *since it will do the job fine. Reflecting just a photo on your car will only cause people to notice the style differences.
*Edited for clarity...
Doesn't have to be a photo, though, so I don't see what vig is getting at. A cleverly made cubemap could go a long way to creating a convincing cartoon car paint look.
I don't have any diff+spec only car models to reference off of so I couldn't really compare side by side, but I'd still like to think that spec is even less important in order to keep the car from looking to matte.
Here's some shots of a friend of mine who used a subtle env map for a content pack for garage games.
Vig I don't know too many engines that don't support simple environment maps, and even these were done in Torque, so I don't see where any engine from the year 2000 and newer wouldn't support such tech.
edit: Didn't see that Vig rephrased his post from when I got to read it this morning. I don't think I've had too varied of experiences with env maps on different engines, but I surely haven't tried em all.
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It's not a perfect fix for faking actual reflections but environmental maps can't be applied to every last little thing that has shine so faking it with a good spec map becomes important.
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Agreed 100% but that doesn't mean that it's useless. It all depends on the type of asset, and cars can be a good candidate for this is all.
Kovac, now imagine what your friends cars would look like had he used colored spec instead of pure white. The spec color also helps create the sub surface scattering effect since the paint underneath the clear coat will effect the spec a bit. That fake-ish looking white spec shine you get when you use pure white for a spec color, even with a colored env map, is a dead give away something is off. Especially when it cuts right across body lines and molding. Env maps alone can look abused and detract from the model which is what most people do the first time they discover env maps. When I'm looking at the environment in the reflection and not the car you've lost focus. Your friend did a good job of keeping it subtle btw.
Edit: My point is, when working with reflections, consider spec and apply a env map almost as an after thought, to polish it off. What he needs to learn can be taught better thru exploring spec then just slapping a env map on it and calling it good.
If you send me your texture I can take a look at it closer, and maybe do a paint over.
Plus I could be wrong, but you have no dirt, which means your car is one of the cleanest cars ever. Even if you were to bleach and sand blast your car clean there will still be dirt and grime, maybe even some slight scratches around movable parts like doors, hood, trunk, at the wheel base, and the chrome rims.
On top of this you have just painted detail, now it's time for texture, a car normally has a porous texture to it's gel coat, find a texture that resembles that and apply it multiplied or screened in one layer to give it some life.
Basically your model has to look lived in so give it some character.
Edit: When doing a color spec map, is it just to use different shades of one color?
When doing a color spec map, is it just to use different shades of one color?
[/ QUOTE ]It depends on the engine you're working with, but 99% of the time you can use any colors you want
Then you can play around and adjust the specular roll off etc..I keep them normally around medium.
Of course like everything else lighting should be final.
AND here's something I found on highend3d for ya...
http://www.highend3d.com/maya/tutorials/texturing/188-3.html