tailieunhanh - CREATING GAME ART FOR 3D ENGINES- P8

CREATING GAME ART FOR 3D ENGINES- P8: Iwish to thank the editing team at Charles River Media (Emi Smith, Karen Gill, Jennifer Blaney, and Jenifer Niles) for their help in getting this book publish-ready. Thanks, too, to my technical editor, Mike Duggan. Also deserving recognition are the guys who make the Torque Game Engine available, GarageGames, who directly or indirectly made this book and the accompanying CD possible. In particular, I want to thank Joe Maruschak at GarageGames for the great articles and forum answers that have helped me and many others get a handle on this engine. I. | This page intentionally left blank CHAPTER 8 CHARACTER UNWRAPPING In This Chapter Unwrapping a Character Overview Unwrapping the Hands with a Planar Map and Adding Them to the Body Unwrapping the Body with a Normal Map Unwrapping the Character s Face Creating a Character UV Template Unwrapping the Helmet Unwrapping a Component Mesh Unwrapping with Multiple Materials IDs Saving Loading and Combining UVs Baking the Texture into the Mesh 189 190 Creating Game Art for 3D Engines Unwrapping a Character-Overview Unwrapping a character is more difficult than unwrapping weapons and pickups because the mesh is more organic. Setting up the UVs properly in the Edit UVWs dialog box can be like putting together a complex 3D puzzle where the shapes keep changing. If you have worked through Chapter 3 Unwrapping Game Art and you are patient you should see promising results with a few hours work. If you are using your own mesh try to keep it simple the first time through. Unwrapping Before You Rig the Model Unwrapping is best done before rigging your model. You can do it later but if you are using a biped skeleton and the Skin modifier is already added make sure that the biped is in Figure mode otherwise when you select faces on the model they may be slightly offset due to minor adjustments in bone position when you switch out of Figure mode. You can also make a copy of the entire character mesh from the rigged character again while the biped is in Figure mode and delete the Skin modifier from the copy. You can then unwrap this copied version of the mesh its UVs are saved and applied to the actual character. As long as the number of vertices stays the same the UVs should transfer from mesh to mesh without difficulty. If you see green lines in any of your UVs that come from an overhang or from polygons that face the wrong direction it s likely you have found some stray vertices in your mesh. Understanding the Impact of Stray Vertices Any stray vertices in your model at this stage of