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The hand is probably even more difficult than our unconventional leg because of the many fingers. Our goal is to use as much texture space as possible as efficiently as possible. With that in mind, we will try to get all four fingers to share the same UV space. To do this, you can delete three of the fingers, UV map one, and then duplicate it for the remaining fingers. You can also manually UV map every finger and match them up by hand. Neither way is easy, and both ways can be time consuming.
Figure 3.24 Auto Mapping the hand
Figure 3.25 Layouts of the four fingers
Figure 3.26 The four fingers’ UVs stacked on top of each other
Figure 3.27 The thumb UV mapped
The body is now UV mapped. You can duplicate it and mirror it (using the negative scale method or using the Mirror Geometry command under the Polygons menu). Duplicating the half will cause the UVs to be shared on both sides. Attach the two sides together as described in Chapter 2. The next step is to position the UV shells in the upper-right area of the UV Texture Editor for texture preparation (Figure 3.28). You still need to fit the armor on here, so you may need to go back and make some adjustments later.
Figure 3.28 The body’s UVs mirrored The body’s UVs mirrored
The armor is similar to the body in that we can mirror the UVs for both sides. Therefore, you can delete half of the armor’s geometry (the emblem on the chest can remain whole). You probably have noticed a bit of a pattern by now. First, we will lay out the initial UVs by using Automatic Mapping. Then, using editing commands (such as Move and Sew and Align UVs) and manual UV tweaking, you can position the UVs efficiently.
Figure 3.29 Mirroring the UVs of the shoulder pad
Figure 3.30 The final wristband UV layout
You will want to share UVs for each of the spikes. Let’s go over a new command that might help with that. First, lay out the UVs for one of the spikes using the methods that we have already discussed. Now, select the finished spike, shift-select a new spike, and use Polygons > Transfer (make sure that UV Sets is checked in the Transfer options). This will transfer the UV layout of the first spike to the second. Do this for the rest of the spikes on the wristband. Make sure you delete the spikes’ history afterward (Edit > Delete by Type > History). You can repeat the process for the shoulder pad spikes.
| Note: Polygons > Transfer works only with geometry that is identical in structure. In other words, you cannot transfer UVs from one of the spikes to a totally different object such as Silenus’s head. works only with geometry that is identical in structure. In other words, you cannot transfer UVs from one of the spikes to a totally different object such as Silenus’s head. |
Continue UV Mapping the armor using the techniques described so far. When you are finished, it will be time to lay out all the UVs of the body and armor onto one map. This can be quite challenging. Figure 3.31 shows how mine ended up.
Figure 3.31 Finished UV layout for Silenus’s body
Here are some tips and strategies to think about while positioning your UVs:
Sharing UVs Silenus is decked out in a bunch of leather straps. Each of these can obviously be very similar in texture. You can maximize the UV space by overlapping these elements and letting them use the same parts of the texture.
There are a lot of areas where you can maximize UV efficiency by stacking UV shells to share their UV space. The kilt is a prime example. Each slat of the kilt shares UV space. The spikes are another example. Each spike is a three-sided pyramid, so each triangle of an individual spike can be stacked, sharing the UV space.
UV Area Size Applicable to Model Size Small items, such as the spikes on the wristbands and shoulder pads, the jeweled emblem on the chest, etc., should be given applicable texture space. Give a small item a small UV area. On the other side of the coin, large areas, such as the character’s torso and legs, should be given as much UV area as possible, because they will be the character’s main objects of interest, aside from the head.
One of the major exceptions to this rule is a character’s eyes. Eyes are the first things a person looks at, whether it is a game model, an actor, or a person standing next to you. In order to have as much clarity in them as possible, eyes should have a bit more UV area than you would normally think.
Mipmapping Mipmapping is the process that the game engine will use to shrink textures by a Power of Two depending on how far the models are from the player’s camera view during gameplay. When a model is up close, it will use the maximum size (512 × 512 in this case). As the player’s camera view gets farther and farther from the model, the game engine will automatically switch to a smaller size (256 × 256, 128 × 128, etc.). This frees up texture memory that can be given to other objects that are closer to view. Shrinking the texture can cause the pixels to shift very slightly. With that in mind, try to keep at least a little bit of space between UV shells, allowing mipmapping a little leeway when it shrinks textures.
Texture Usage in Gameplay The hair tuft planes on the elbows and back of the legs will be put on the head texture where similar hair from the beard will be mapped. You might do something like this for gameplay. In whatever kind of game Silenus is in, he may use lots of different kinds of armor and costumes. By mapping this hair to the head (which will usually keep the same texture throughout the game), you can avoid having to put this hair in each different armor texture you make.
Use UV Snapshot to create the UV layout as an image you can use in Photoshop. Because you will be planning for a 512 × 512 texture, you will save the layout as a 1024 × 1024, one Power of Two larger.
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Created: March 27, 2003
Revised: January 10, 2005
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