How do I link multiple meshes to one armature and apply Inverse Kinematics without distorting mesh?

Question

I’m trying to to rig and animate a set of meshes that are 3d scans of a horse’s leg bones. Each bone is a separate mesh. I only need the bones to rotate on one axis (y-axis in the screenshot) and move up and down along Z-axis.

The screenshot shows the 4 main positions I am attempting to achieve. I followed the Blender 2.8 fundamentals tutorials and attempted to achieve these positions following the basic IK elbow rig, but to avail. I think I’m having trouble with the fact that my objects are all separate meshes and I’m not sure who to parent to what, and which bone to reference when setting up the Inverse kinematics (or maybe this isn’t the way to do it?)

So far the closest I got was parenting all of the meshes to the uppermost leg bone mesh, then created the armature by extruding each armature bone from the last, and parenting the armature to the meshes. I duplicated and disconnected the lowest leg bone as if it were the hand, but had no luck being able to rotate the boney column with it.

The other issue I encountered was that I can’t seem to keep the mesh from distorting, when really all it needs to do is pivot at the articulations as the actual leg would. I first tried automatic weights and then found the closest I could get to no distortion was to fully weight paint each bone, but there is still some mesh distortion, and I wasn’t able to create the full range of motion I was hoping for.

If anyone has any suggestions your help would be greatly appreciated.

Answer 1

Alright, so what you want to do is first make a bone rig that follows the mesh. You then want to parent each bone to the mesh, using empty weights. If you move the armatures now, nothing happens. There are empty weight paints that are parented to each armature.

Now, you want to select the armature, go into the Object Data properties tab, go into viewport display, and select names. This will show the name of each of your bones. Then, select the horse bone, and figure out which armature bone should move it. Since you have "Show names" enabled, you should be able to see the name of the armature. THen, with the horse bone selected, go into edit mode, and press "A" to grab all vertices. Go into the object data properties with your horse bone selected, and under vertex groups you should see the name of the armature one that you what it to be parented to. Select the vertex group, (while in the horse bone's edit mode) and click assign. now if you move the armature, it should move that horse bone.