Rigid Skinning and Membership Editing
Select the Body node, which should contain all the geometry to be skinned, and the root joint; then apply rigid skinning with Coloring on. Move the Child node, and you will see points shooting out. Use the Edit Membership tool or the Paint Set Membership tool to go through all the joints that are double-transforming and remove the offending CVs, as shown below (and in the Color Gallery on the CD). Hide the surfaces and meshes, and reassign the lattice points to the spine chain in the following way. There are eight rows of lattice points, but the bottom row should be influenced by the legs, so leave them alone. Assign the second row to the spine joint, the third row to spine2, and so on. The chest joint gets the two middle CVs of the seventh row and the top two middle points at the front and the back. The forearm CVs are assigned to the wrist joint, so they will twist with the cube. When you are doing the legs, if there are many incorrectly assigned points, it may help to spread the legs out a bit. Go through other parts of the body roughly because you will find when you are weighting the surfaces that younll need to reassign some points. Weighting points and editing their membership is necessarily an iterative process.
Preserve Skin Groups and Correcting Errors Oops! Wenve made a horrible mistake, as so often happens in real life. We discover when we test the arms that they are too short, and that the hand joints should be placed closer to the hand. But wenve already skinned the geometry to the skeleton, and the skeleton has the cube constraints already in place. What do you do? Mayans Preserve Skin Groups to the rescue.
LetDs correct our terrifying mistake at once. Select the skeleton group and apply Skin > Edit Rigid Skin > Preserve Skin Groups > Detach Skeleton. Select the arm IK handles and in the Attribute Editor disable the IK Solver. If youDve locked the translation attributes for the joints, you also need to unlock them. You can now translate the elbow and the wrist joints to lengthen the arm. To place the hand joint closer to the hand, use the Insert key to move only the hand joint, as shown below. Move the wrist joint as well. Before you reactivate the IK Solver, youDd also want to snap the cube to the new wrist joint position. Select the CVs of the arm and the hand and lengthen the arm, keeping the proportion of the CV positions. Make sure the fingers match the finger joint positions. Select the skeleton group and apply Reattach Skeleton.
Maya may warn you that the bind position has changed for a number of joints. Detaching and reattaching skinned objects may necessitate some reassignment of point membership. In our case, because the wrist and hand joints have moved closer to the hand, we need to update the previous set of membership of those joints and perhaps that of the thumb joint. Everything else should work just as before.
This was an easy example of correcting a mistake in the setting up stage. In a production situation, one of the most frustrating things is to discover too late that thereDs a problem with the character youDve built. So right now would be a good time to check again what you have done so far for any potential problems. Once youDve gone through weighting a character, you will not want to weight it again.
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