Post Thirteen

Skinning

In this post I get to skin my character, The first thing to do is to delete the turbo-smooth that I have added to my character in the modifier panel, putting a skin modifier over the top would be just stupid as there would be too many vertices to weigh and modify with the envelopes, also I have animated the control objects to move the bones so they stretch and do a simple walk cycle, this helps a bit when I test the envelopes later, as I can just run the test animation and see how the envelopes affect the mesh.
So with the mesh and the bones all ready to go, I select the skin modifier from the list and then under the parameters roll-out I click the add bones option and select all the bones making sure that only bones are selected for the skin.
The next thing to do is to select a bone from the list and click the edit envelopes option, the envelopes control which part of the mesh will be affected by the selected bone, red ares mean that 100% of the area is affected and blue areas are almost no affect, orange and yellow are somewhere in between, as you can see in the next image the spine bone envelope I have selected is affecting other ares of the spine, the arms of my character and even his neck, now there are a couple of ways I can modify the envelope to affect only the spine I have selected; I could move the evvelope but this is not the way really to do this as by moving the envelope and making is smaller, I am only making other envelopes bigger, the way to do this is to weigh each vertices and select the specific bones to affect the specific vertices, it takes some time but at least it makes sure all the vertices are being affected by the correct bone.
To weigh a vertices I must scroll down under the edit envelopes option and check the vertices box, then scroll down to the wrench like icon to open up the weigh vertices box.
In this image I have selected the vertices where the arm joins the body and as you can see from the weigh vertices box it is being affected by several bones; spine3, spine4, clavicle, upper arm and head. Now we know for instance that the head bone shouldn’t even affect this vertices, so from the box we select the head bone and click on the 0, this makes the head have 0% affect on that vertices. Now for this instance I will make the spine bones have 0% influence too, this will leave just the clavicle and the upper arm to affect the vertices. I will go 50-50 and then come out of edit envelope selection and move the wrist control object around and see how this affects the join of the arm to the body, I will add the turbo-smooth modifier back to the list of modifiers but I must remember to turn it off and select the skin and the envelopes when I want to change the weight again. The turbo-smooth was added because this is what my character will look like at the final render, it all looks ok so I move on to the next vertex. It is a long process, but all I have to do is one side of the body and then replicate the amount for the other side’s vertices. It has taken some time but I have a test animation and it all looks quite good.

Just before I post the animation I would like to point out something I have noticed, there are a few anomalies where the leg tries to poke through his shorts, and after much deliberation I have put this down to bad modelling technique, if the leg inside the shorts was lined up properly with his knee instead of up over the knee I would not be getting this problem, all I can do is try to limit the bend so it does not poke through, I have tried to fix the problem but I am so far ahead of the modelling process not much can be done about this problem and when I have tried to roll back to edit the vertices, the rig fails to work, the envelopes and the vertex weight is correct as far as I can see, so this is a shame but with clever camera angles, and limiting the bends of the knees hopefully the final animation will not show this. Without further ado here is the test render: