I've been having some problems with deformities whilst posing the limbs on my T. rex model. The problem occurs on the thigh and all of the arm bones.

Not posedNot posed

Posed thighPosed thigh

Whenever I rotate the left thigh bone it causes areas of the mesh on the right side of the model to distort and follow the bone.

Leg angled to sideLeg angled to side

Rotating left arm joint distorts rightRotating left arm joint distorts right

This happens with the arms and clavicle bones. The bones are mirrored and both thigh bones are parented to the pelvis bone in between and slightly to the front.

Any help would be greatly appreciated as this problem has troubled us for weeks.

  • $\begingroup$ This is a common question here at Blender Stack Exchange (BSE). Nothing New. When you look at this web page on the right side is a [related] column which has similar questions. Please search here at BSE to find a similar question to yours. You should show images of weight painting in your image because they likely matter most. You may need a video tutorial series. The following is part of a series .... youtube.com/… . um oh .. PS I forgot to say Bienvenidos at BSE. $\endgroup$ – atomicbezierslinger May 25 '16 at 0:28
  • $\begingroup$ Make sure you have named the left and right bones correctly. Have you applied mirror modifier? Often auto-weights don't get everything perfect, just tab into weight painting mode and fix them. $\endgroup$ – kheetor May 25 '16 at 5:27
  • $\begingroup$ there is a mirror modifier in place and the model is weight painted. the problem is that the bones on the left affect both the vertz on the left and the right side of he mesh. I'll look into the links you posted $\endgroup$ – Paleop May 25 '16 at 10:35
  • $\begingroup$ ok the bones are named right however $\endgroup$ – Paleop May 25 '16 at 10:40
  • $\begingroup$ i.imgur.com/aTLtA7E.png $\endgroup$ – Paleop May 25 '16 at 10:40

This issue likely is occurring because vertices on one side have been assigned to bones on the opposite side.

When using a mirror modifier, this issue can be easily rectified by simply un-assigning all vertices from the right side—this can be done manually through the Vertex Groups area in the object data panel (just select all vertices in edit mode and click "remove" for all bone-related vertex groups whose name ends in ".r")

Another option (when using the mirror modifier) is to go through each of the right-side bones and subtract the weight from the left side. (However, when using a mirror modifier this will NOT work by selecting the left-side bones and removing weight from the right.)

If the mirror modifier is not in use, just do the second process on both sides—i.e. remove from the right bones vertices on the left, and remove from the left bones vertices on the right.


From your 3rd and 4th image I see some meshes come out with your thing bone.So You can easily do this with weight painting. just select Your Armature -> select your body with shift and then press Ctrl+Tab. In weight painting mode you can paint you modal mesh with respective bone. You can understand this with weighting tutorial. just search on google for wight painting blender 2.7.

And one more thing If you have not applied your mirror modifier to mesh then do this first. If mirror modifier not applied then when you move one side bone other side mesh will also move same.

  • $\begingroup$ there is a mirror modifier in place and the model is weight painted. the problem is that the bones on the left affect both the vertz on the left and the right side of he mesh $\endgroup$ – Paleop May 25 '16 at 10:33
  • $\begingroup$ From your image I see that your right leg move with thing. bone so check that bone name is given perfect or not like thing.l and thing.r. $\endgroup$ – hardwork May 26 '16 at 6:10
  • $\begingroup$ If this is perfect then From your image result I can say your modal is not properly weigh painted. When your two legs or hand mesh near to body mesh or near to each other meshes and you apply automatic weight painting then it also affect near other hand or leg mesh. So go to weight painting and check that all leg parent bone weight painting and also child bone weight painting for this. I hope this solve your problem. And don`t forget to apply mirror modifier before start weight painting. $\endgroup$ – hardwork May 26 '16 at 6:15

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