artifact arises during rotation in pose mode

I’m following a character animation tutorial.

While rotating the under arm in pose mode, a mesh artifact arises at the hand pointing at the original direction.

At rest the hand is horizontal and has no artifact. The artifact grows while the arm is rotated upwards. What could cause this phenomenon?


Your image isn’t displaying, but what it sounds like is that you just dont have all of the verticies parented to the hand bone or you have them parented to other bones creating an addative influence.

Weight painting is used to connect the armature bones with the mesh.
Indeed vertices are sometimes connected to more than one bone with weight painting.
However I can not find vertices that or not connected.

An easy way to make sure the problem isn’t verticies that arent parented is to go into pose mode and rotate the bone to create the artifact. Then go to the weight painting of the object and paint over the artifact. If the verticies weren’t parented, they will snap into place, fixing the artifact.
If that isn’t the problem, could you post a .blend file?

Thanks so far Asano,

I can diminish the artifact, but not completely remove it.

So I will post the blend.


loopcyclus test.blend (300 KB)

It was just addative influence. Some of the verts in the hand are weighted for the bones: shoulder.l and ruggengraat5. Select those bones, weight the hand verts to zero and that solves the problem.

Thank you very much Asano,

Problem solved!
This has increased my knowledge of weight painting.

You can also use the Edit Mode tools to completely Remove the hand verts from any vertex groups where they don’t belong. This is a step beyond putting their weights to zero, and is a good practice to follow, as it lets you be specific about which verts are influenced by which bones. Then if you use the “VGroup” option in the Weight Painting panel, you can’t add weight to verts that are not already in the selected bone’s vertex group.

Not related to your question but Antony41 do not use the file:// protocol when linking images as this points to the local filesystem either use a image hoster like and use the http:// protocol to link or better attach the images just like you attached the blend file.
You can even use the clip button after you uploaded the image to display the attachement inline.

That’s good to know, opens new options…

Chipmasque, do you mean to manually select the vertices that you want to remove, then click through each vertex group that shouldn’t have them one by one and click Remove on each? That’s what I’ve had to do sometimes when I’ve inadvertantly got vertexes assigned to wrong/several groups, but I’m wondering if you aren’t hinting that there’s an easier way to remove from ALL groups at once, or multiple groups at a time.

I didn’t know about that button! You just made my life easier. Thank you very much.

Well, that’s one way, and in answer to your question, no, I haven’t found an “easy” way to clean up vertex group population other than by using the Clean Weights script. It does take going through every vertex group to check on its membership. My Katrice model has a hundred or more VGs, so it’s a helluva task, but essential now & then just to make sure things are going to work as expected.

My usual process is to go into Edit mode, choose a vertex group, Select those vertices, and inspect by eye. If there are some strays, I’ll use the “Paint Selection” brush (BKEY-BKEY) to deselect those I want to stay in the group, then hit Remove, for any left in the selection (the strays).

If you do this after every Weight Painting session where the VGroup limiter wasn’t used, you can focus on only the VGs you painted to, and keep things clean on a session-by-session basis.

Just as a side note, I often use VGs that are quite a bit broader than the portions of them that have actual weights, in other words, many have zero-weight verts in them. That way I can paint new weights into the fringes of VGs without having to disable the VGroups limiter.

Interesting method. Thanks again!