Armature Mesh drags when posing bones

Question

I've been trying to get a functioning human-like mesh working for a while now and tried making a fairly rough and simplified version with the body being segmented so I don't get any deformation that might break the mesh for testing purposes (As in; one segmented part of the mesh for one bone).

The problem that came up was that on certain parts of the mesh it would sort of drag while posing it, despite me weight painting the whole segment until it's red so that it should be rotated with barely any actual changes in the overall structure of the mesh

I intended the bones to actually stay inside the mesh, but the way it kind of warps the mesh it isn't really working in some parts of the armature and I'm not sure why.

Sorry if the question is a little confusing or unspecific. I've been trying to learn blender for a while now and despite some progress I feel like I'm always just missing something that would help me, so I hope my whole methodology isn't too frustrating

Here is my file in case somebody wants to take a look at it. The problems seem to largely be in the fingers of the model. All other parts work largely as intended from what I've tested so far

Answer 1

There are actually weights of 1 that are assigned to more than one bone, specifically all of the fingers have, additional to their respective finger bones, an assigned weight for the "Hand L" bone. That is causing your problems. Since two bones have an influence of on the fingers, they keep an "average" position if you're only rotating the finger bones. I assume you assigned the weight there to make sure the fingers move with the hand. This isn't necessary, in fact that should be avoided, because the bones always move with their parent bones and have each a portion of the hand assigned to them, therefore making this obsolete.

Anyways, you can easylly recognize such problems by clicking the armature and SHIFT-Selecting the mesh, then enter Weight Paint Mode. By ALT- Clicking on the bones you can now see their respectivly assigned weights for the mesh.

To show how helpful this is, I made a picture of this while pointing out the problem:

To get rid of the problem fast, go into edit mode and select just the base of the hand (because your mesh consists of non connected parts, the fastest way is by hovering over one of it's vertices and then pressing L) now invert the selection with CTRL+I. In the "Properties" tab got to Vertex groups under the "Data"-panel and select the "Hand L" Vertex Group, just click on "remove" to remove the selected vertices from the selected Group.

The deformation of the Armature should now work exactly as you wanted it to.

I hope this helps