Modeler

Chapter 8: Map Tab 257Bones inside “branching-type” geometry, like fingers, can beproblematic when the weight map is created using a falloffcalculation without any correction. Bone deformation will likelyaffect areas you wish to be independent. This is because thefalloff calculation is performed referring to only the distancebetween a bone and a point.The Edit > Trim Branch function solves the problem by allowingyou to trim the weight for the current weight map. It first calculatesthe “primary bone” for each point (i.e., the bone closest to thepoint). If the bone is not a descendant of the current bone, theweight map value that the point holds is cleared. “A descendant”is a “bone route path” generated from one parent (see Fig.3).NOTE: If you use this command where the boneroute path branches, like at the base of a finger, itmay not deform smoothly. As such, try to use thiscommand where there is not bone branching. Also, trimmingmay not work well depending on the bone location. If youencounter this problem, try using the ERA or SUB paintingoperations to adjust the weight value.Bones on the red line represent a descendant of the current bone,and bones on the blue line represents the other descendants.Painting WeightSelect the Paint subtab on the Weight tab to “paint weight.” ThereBefore using Trim Branch. If you bend the finger using thehighlighted bone, neighbouring fingers will also bend becausethey have bone weight.After using Trim Branch. Unnecessary weight for the points onneighbouring fingers have been erased. You can now bend thefinger independently.