Armature and weight painting issues

[jujube]

(I wish there was an equivalent for sculpt mode, though... right now in sculpt mode you can't really do the eyes for instance very well, the eyelashes are in the way.)

https://wiki.blender.org/index.php/Dev: ... lpt_Hiding

I knew about alt+b but not about this. I just tested it, it works on a subdivided cube but not on the basemesh. (I hide things, nothing happens, and go to edit mode and the verts are hidden there.) Also it looks you can only hide things in a box select, which would still make it hard to grab the eyelashes. I was thinking I wanted to hide vertices by selecting them directly, through vertex groups or similar.

Also @wolgade: with that method, doesn't it apply the weight to all the vertices? so unless you can fuse two differently weighted vertex groups, (maybe you can? I don't know) it's not useful for what blindsaypatten is doing.

[blindsaypatten]

... for what blindsaypatten is doing.

It's B. Lindsay Patten so please feel free to call me Lindsay

[RobBaer]

(I wish there was an equivalent for sculpt mode, though... right now in sculpt mode you can't really do the eyes for instance very well, the eyelashes are in the way.)

[/quote]
You couldn't move the lashes to a different layer?

[wolgade]

Also @wolgade: with that method, doesn't it apply the weight to all the vertices?

It applies the weight to the selected vertices. As I'm not entirely sure whether we're talking about the same thing, I'll show what I mean.

Unweighted cube. Switch to Edit Mode, select vertices, choose weight, assign weight.

Result:

Let's repeat this with a different weight.

[punkduck]

Even if some people now think, that for a cube it is okay but for a full body ... in the past I watched an interresting video on youtube showing you that the professionals also use the manual method.

So, here is the video about the Sintel character (I'm not sure, but I guess it is Angela Guenette, who made the character, explaining):

https://www.youtube.com/watch?v=ECP92JyUwrY

[jujube]

In your screenshot I see the weight slider, but I don't see an assign weight button, just an assign vertex groups button. Or... wait.... is that what the weight does? I assumed it was a slider that affected the whole vertex group. So what's actually happening is that every time you press assign, the vertices you just assigned to the group are given whatever whatever the weight setting was at the time.

@RobBaer: I'm not sure what you mean by layers. If you mean the usual type of layers with the check boxes at the bottom of the screen, then won't moving the eyelashes to a separate mesh mess up the vertex order later when you put them back on? (Because while maketarget lets you set as base, I thought that when you use a base other than the one maketarget/makeclothes gives you, it gets messed up. )

This shows how much I still have to learn about blender... (or alternatively, I should stop assuming that the blender devs are a bunch of big meanypants who would definitely never let me do the thing, and instead ask "how do I do it?". )

[blindsaypatten]

So, as I mentioned in another thread, using my generated default weights file broke some things, including the eyes no longer moving with the head and clothes no longer moving with the body. I thought I was just changing the weights around specific joints and that everything else would stay the same but it appears not. I don't see why the connection between the eye and the head should be affected by changing the knee weights so clearly there is something else going on, quite likely the issue of painting helpers that was raised earlier.

I had a moment of clarity while looking at my (own physical) knee this morning. Movement of the skin surface is only indirectly related to the movement of the bones involved. What really determines surface movement is the muscles attached to the bones that the skin then sits on top of. In the case of the knee, the thigh muscles attach to the lower leg bone below the joint so when the knee is bent the inside (back corner) where creasing occurs is sitting on the muscle a good distance from the joint, and more importantly, at the surface so the crease is very shallow. For weight painting purposes there ought to be another "bone" that represents the muscle and its attachment, and that is what the skin should be weighted to. To complicate matters of course muscles change length so you would need drivers that adjust the bone length as the knee bent.

The skeleton model of surface position and movement is fundamentally wrong, and fiddling with the weights will never produce anything realistic, just a tad less unrealistic. I could create a new armature that incorporates "muscle bones", but MakeHuman always uses its own default skeleton internally so it won't work within MakeHuman.

So a fundamental rethink is needed.

Edit:
I think this is a more accurate model of at least the back of the knee. I'm not sure of the implementation of the armatures so I'm not sure whether the two muscle "bones" need to adjust length and/or have a joint between them. The main point here is that the distance between the intersecting skin segments and the intersection of the bones determines the depth of the crease that is formed. In real life the crease is only skin deep.

[wolgade]

For weight painting purposes there ought to be another "bone" that represents the muscle and its attachment, and that is what the skin should be weighted to. To complicate matters of course muscles change length so you would need drivers that adjust the bone length as the knee bent.

The skeleton model of surface position and movement is fundamentally wrong, and fiddling with the weights will never produce anything realistic, just a tad less unrealistic. I could create a new armature that incorporates "muscle bones", but MakeHuman always uses its own default skeleton internally so it won't work within MakeHuman.

You actually discovered the concept of having a deformation rig which is driven by a control rig. That's exactly how the MHX rig works. You might want to have a look at it.

[punkduck]

So here we are again with my extra bones I mentioned before --- and I hoped so much that I will never have to attach these bones again. I have used shape-keys also, btw. Does somebody know if these things are reusable? When I re-export my models I've to create the keys (and extra-bones) again and again ... I'm using keys for the size of the pupil in the eyes also btw.

[Mindfront]

:?

So here we are again with my extra bones I mentioned before --- and I hoped so much that I will never have to attach these bones again. I have used shape-keys also, btw. Does somebody know if these things are reusable? When I re-export my models I've to create the keys (and extra-bones) again and again ... I'm using keys for the size of the pupil in the eyes also btw.

I dont know about reusing bones but you can reuse a shape key by copy it to another mesh that have the same amount of vertices and topology. As I know you can only copy one shape key at a time.

Select the mesh, that have the desired shape key and select the shape key you want to copy.
Shift select the mesh that shall receive the shape key, then in the shape key window select "Transfer Shape Key". Unable pin.

Blender Transfer Shape Key

If the receiving mesh does not have any shape keys a "Basis" will automatically be created.