Targetware: 3D Dev Guide
Texture Mapping Tutorial: Beaufighter
Pre-Mapping:
As you build your model, assign groups using 'groups', colors, layers, parts, or whatever your program allows. This will let you easily split it up later when you are ready to map it, and when you only want to work on particular sections of the model. Make sure you are happy with the 3D geometry of the model before proceeding to the mapping stage. The model should be complete, with all the parts you believe you will need already done. Control surfaces should be present and cut out. The fuselage and wings should be split up into their various parts. You do not want to have to go back and change geometry after you map something, because you'll most likely have to redo the mapping as well at that point.
Step 1: Making UVs
The geometry is set, it's time to map the parts. If this is a plane, you have 2 texture sheets to work with, so divide up your plane into what will go on the first texture sheet, and what will go on the second texture sheet. You don't have to get it exactly right the first time, you'll probably end of shifting some things from one sheet to the other later on to make everything fit. Select the polygons for the first texture sheet, and have the program make a UV map for the parts selected. How exactly this works will depend on the 3D modeler you are using. If your program has an "unfold" or "atlas" function, that is generally your best bet to start with. If it doesn't, then you'll have to be more careful, and use selective planar mapping. Later on, you may wish to use a different style of mapping, cylindrical, for example, on particular objects. But for now, just get everything onto a UV map.
Step 2: Sort & Re-assemble Parts
Most likely, you now have a whole lot of large and small polygons on your map that make no sense at all. Sort these into recognizable groups. For example, you might start by finding all the parts having to do with the landing gear, and moving them into one area. Don't worry about staying within the boundaries of the texture map right now, you can fit everything inside it later.
After you have sorted out your parts, re-assemble the parts on the texture map. For example, if you look at the texture map shown above, you'll see that the wings are not all in one piece. Carefully move the UV parts together so that they are in the shape you want them in for painting. Parts that share edges in the model should share edges on the UV map whenever possible, unless a clean color break is desirable.
Step 3: Mirror Where Possible
Move any part that can be safely mirrored onto its twins. For example, in the bottom center, there are two long narrow blobs. The top contains the end caps for the h stab and elevators, the bottom is the end caps (lengthwise ones) for the flaps, ailerons, and wing backs. Also, landing gears should be mirrored, as well as wheels: A wheel is a wheel (but tail-wheels are different). Gear bays, end caps, anything that won't need unique paint should be mirrored. Propellor blades can be mirrored, but should have separate back and front surfaces. That takes up a fraction of the space a 'disk' shaped surface would require to get the same detail, and the blades can fit into any narrow left-over spaces you have. Remember: don't mirror fuselage sides, wing surfaces, or anything that will need unique paint.
Step 4: Move Large Parts into Place
Start with the most important and largest parts—the wings, for example—begin moving parts into place on the texture map. Don't worry too much about orientation, the 2D artist can take care of most things. Rotate, flip, and scale parts in order to make the most of the space available. On the zero, where there are no wing engines to worry about, we were able to give the wing surfaces even more space than we have with the beaufighter here; and that corresponds to more 2D texture detail and a better looking airplane. On the fuse map, the first thing to layout would be the fuselage, it should run the full length of the texture sheet. When arranging fuselage parts, try to line up the two sides (and any top/bottom slices you may have) so they match each other. That makes it a lot easier to have panel lines, camouflage, and other details match up across the two sides of the fuselage.
Step 4: Big Parts in Place Step 5: Fit Remaining Pieces
Once you have your most important objects fitted, start sizing and placing the rest, with an eye to the space you have remaining, and the relative importance of each object. Some objects don't need a lot of detail, others can benefit from a bit more, proportionally. A cockpit won't require much texture space on an external model, but you might want to give the instrument panel portion a little more than the rest, so details can be made out.
Step 5: Filling in the Details Step 6: Export Texture
The next step is to create a TGA file that shows the layout of all the polygons used on the texture map. The file should be in the size allotted to your project (512 pixels by 512 pixels, most likely). The details of creating this file will differ from modeling app to modeling app. After creating the file, go back and assign the texture map you just made, and the texture file you just created, to the parts just mapped. Your template texture should now be showing on the airplane.
Step 6: Exported Texture Applied to the Model Step 7: Label Parts (semi-optional)
The final step is to open your texture template file in a paint program and add labels to describe any parts that aren't obvious from their shape. You can skip this step if you wish, but the 2D artist will probably end up coming back to you and asking about what's what anyway... Remember, he won't have the advantage of clicking on a part in the modeler and seeing what part on the map lights up.
Step 8: Wrapping Up
After you finish up both texture maps, it's time to send the polygon templates you made to the 2D artist who will be painting your plane. If you are going to paint your plane yourself, stop reading, you are done. Otherwise, pack up the template textures, some basic version of the 3D model, and an .anm and .acm file for the plane, and send it off to the 2D artist. The 3D model you send doesn't have to be animated, or even cut up, it just needs to be viewable in-game so the 2D artist can see what he's doing. In fact, you might want to wait to cut up and animate your plane until the 2D artist has finished. Chances are, you'll have to adjust some of your mapping, and it's a lot easier to do that when the model is still all in one file.
|
