Other Pages:
3. Low Resolution Modeling and UVs
5. Links and More Useful Stuff
I'm going to try to stay renderer agnostic as all of these maps can be baked in a number of ways using ZBrush, XSI, XNormal, Faogen, Turtle, etc. The one thing that I will say is that hopefully you can get a baking package that gives you some flexibility. Ambient occlusion, SSS and SHarmonics are all great but it's also neat to experiment with procedural textures and different lighting techniques, baking them out and simplifying your texturing task or creating a new aesthetic you think is groovy.
For most of my baking I use Turtle. It's extremely fast, predictable, intuitive and hard targeted to do this kind of work. I'm really starting to appreciate Mental Ray. It can be beautiful but it's SLOW. To get a demo and to see every kind of tutorial you'll need to use it, head over to the web site of Illuminate Labs.
Below I'm going to go over a bunch of different textures that you can bake out and then show you screenshots of the model with those textures applied. I'll also blab a little bit about how I use each one. Note, I did not use all of these textures in the final textures for this model, I just baked them out so you could see them. For the actual model textures I used occlusion, normal, noise, selection sets, spherical harmonics and that's it. In Turtle, all of the baked images below are a simple checkbox. Once you have your sampling ranges set up, you're done. Getting all of these renders is then a simple matter of choosing what you want to bake out.
These images are big so I did reasonably sized ones for the textures on this page. If you click on them you can see them bigger.
This is the main one right? The normal map makes the low resolution model look high resolution. Keep in mind there are tons of methods for creating detail in your normal maps. You can bake from high resolution assets and then use photoshop to overlay the details of another normal map. You can also assign a procedural bump map to your high resolution model in Maya and then bake that out along with the high resolution detail. The reason this is groovy is because you will never have any seam problems this way. The only point is, it's easy to get creative with normal maps to add variety, speed up workflow and help raise the bar on art quality. The main normal map here was baked from the high resolution model. The small detail normal map (wood grain, nicks, numbers and text) was done in Photoshop. The leather guard on the stock was brought into XSI because Maya can't handle polys and I was ACCIDENTALLY careless with my poly count there. I love going overboard but I'm a game artist so know when to reign that in...)
I also included an image with no normal map here so you can see how low resolution this model is:
This is a great way to speed up texture creation. I find that baking out an occlusion map and then adding quick overlays in Photoshop gets me 80% the way there (Overlay examples below). Generally you can just multiply this over the top of your colored texture but it's well worth stating that you can also use this map as a selection mask for an adjustment layer to get some neat and varied results. For example, say you want your non-directional stuff to be a color other than black to make things interresting.
The image below looks psycho but it's really straight forward. The R, G and B channels represent a different light direction. When rendered into an RGB image it looks crazy like this. However, if you look at the following images you will see that it gives you some nifty lighting directions that can be screened or color dodged in Photoshop to help give your assets more volume. When used with high resolution geo its GREAT for adding detail.
Note: You need to be careful about this because you don't want to fight the lighting in your game engine too much. Generally it works best to sexify smaller assets. A large fountain with a strong harmonic applied might look strange in the game. But in general when used carefully, I find it gives most assets just a little something extra.
Here is the rendered image:
Here are the R, G and B channels separated out.
Here I took the SH map and screened it over gray to serve as a base texture:
There is no lighting in the image below and that's important to realize. It shows you that the SH map has a directional component, unlike occlusion.
I'll be honest. I don't use this much but I want to show it to you. Image base lighting uses a light probe or other HDR image to illuminate your object. A light probe is basically a high dynamic range environment ball (but can be LDR too). Here is a link. I find that image based lighting has a little too much character to be baked into my color texture. It's extremely environment dependent. I think it may be cool on some sort of reflective surface to add some interresting hues but in general I like the monochromatic nature of Spherical Harmonics and Occlusion. Try it. Overlay it. See if you like it. Use it if it makes you happy.
This is handy. If your baker is a plug-in for Maya you can make a shader and bake out any channel of it lit or not. That's pretty mind boggling but here's a simple example. I plugged the 3D procedural cloud texture into the color channel of a Maya shader and rendered it out with no lighting (albedo). The great thing about this is that the noise generated will not create any seams because it's...procedural 3D noise.
As a side note, I use a cloud texture for darn near everything. I use it very subtly and it just helps break up my flat textures when used as an overlay.
I don't think there is a lot of explaining to do on this one. Either your game engine will use the texture directly somehow or you can use it on characters (the color channel) to make your texture feel a little bit more luminous like skin really is. It's gnarly bizarre on a sniper rifle flesh weapon here...but you get the idea.
Here's just a trick. If you keep your Maya scene organized it's easy to select all the little bits that make up your high resolution model. If you then assign a black or white color to those bits and bake them out as albeto color, you have instant selection sets for Photoshop where painting masks would be way more complicated. Paste these bakes into the channel layers of Photoshop and use them to mask out all your parts when you paint. Great stuff.
Here are some examples of the overlays I used in Photoshop. It all depends on your surface but these worked fairly well for the sniper rifle. These are not baked out by the way. These are just textures from a "grime" library. A grime library is ver important. Actually, I can't wait to work on a game where it isn't important...)
Next Step - Texture Creation >>