Bone rotation scaling vertex group inwards

This is my first post so it wouldn’t let me upload the model. I have a question about rotating bones. I have a model with several vertex groups for each part of the body. It’s a rigid body so no scaling should be applied.

I have my bones named after each vertex group the are set too and at the center of each group. The problem is when I rotate a bone the close I get to the 180 degree mark the more it scales the vertices inward.

The bone is set to have a 100% influence on all vertices in the group. Not sure if that helps any.

All I’m trying to do is get the vertex group to rotate around it’s center mass which is where the bone is placed without scaling.

Uploaded file to my site if you want to give it a test. Try rotating the tank lid or the seat and you’ll see what I mean.

That sounds like vertices are not completely bound to the bone, can you check their weights individually from edit mode ? (in the N region you should have a list of all weights on selected vertices)

I uploaded the file to my site as a zip. If you want to try rotating the tank lid or seat you’ll see what I mean. It should be weighted to the whole vertex group.

Yep that was it… select all vertices that you want to correct, make sure one of them is active (clicked last), then look in “vertex weights” in the N region (sidebar), delete the irrelevant weights (click the cross), then click copy, and you should be good.

1 Like

Yeah so I’m clueless. I selected the vertices in edit mode pressed N sidebar I don’t see anything but something that says mean weight. I’m not following you at all.

Did you make sure one vertex is active ? the vertex weights panel, much like anything in Blender, displays information related to the active object, or the active vertex in this case (although that’s changing soon, but for now this is how it works). If no vertex is active the panel just won’t show (which I think is misleading design, but then again that’s how it is).

Thanks, I got it. Box selecting doesn’t work. You literally have to manually click or shift click a vertex in a group. Not very intuitive but Blender has never been know for being user friendly :slight_smile: Then I deleted the base part and copy the it works fine. I’m still not sure what the copy function is doing there.

Agreed that box/lasso selection should make a vertex active. I don’t know if there’s a good reason they don’t ?

The copy button simply copies the weights to all selected vertices (the weight list only concerns the active vertex).