HELP: Weird mesh deformation

Hi all

When I animate my book opening (see, there is a weird mesh deformation taking place around frame 82/83. I have absolutely no clue where that’s coming from… Ideas anyone? Must be something really obvious to anyone but me…



For me the mesh is deformed until frame 83. The spine of the book is split in two up until that frame when it jumps into its correct shape.

How did you apply the armature? I see you have vert.groups and envelopes buttons both pressed, which isn’t usually advised but that doesn’t fix this (for me). It certainly appears you used vertex groups yet none of the groups show when the mesh is in edit mode and no weights show in weight-paint mode. Did you use bone heat or some other method?

Edit: I’m guessing you did use bone heat and maybe it still has some quirks? Try using good old vertex groups instead. VGroups are always the best solution and you know that because it’s the most painful, time consuming way of getting an armature to work for you :slight_smile:

Well, no, I use vertex groups, but the vertex groups are defined on an IK chain that is on bone layer 2 (not 1) in order to get smoother control. The bones you see on layer 1 are only used to control the bones in layer 2 which in turn control the mesh…

By now I found why it happens… Bone Cover1.R is tracking a helper bone in order to move the way I want it to… what it does however at frame 83 is roll 180°. This is what is deforming the mesh…

Is there a way to “lock” the roll of a bone? I.e. make it NOT roll ever (even if this makes “Z” point downwards)? Or is there a better way altogether?