Character skinning...arrgh!

[CAAB]

Wups, sorry. The file link works now. :airguitar

[svenip]

i'll give it a try. normally you will never get a good result just by apply the smooth skinning. you have to weight etc.

[CAAB]

Thanks.

I've tried painting weights at length. Even with denormalizing the skin and holding weights to make sure nothing else changes while I'm painting.

[svenip]

i just found out a big problem. you haven't created texture coordinates. i don't have the time to do this. but it's absolutely necessary before binding.

can you do this please before ?? :)

[CAAB]

Hmm, I had no idea. I hope that's my problem.

time to read up on texture coords.

[svenip]

yep, thats definitly a problem. because smooth is working with maps which require UV's. now you didn't layout them, they are lying on top of each other and if you paint one piece of your skin it affects many parts, because their UV's lying in the same space.

[iC4]

hm, you have to create texture coordinates before binding a mesh to a skeleton ?!

[svenip]

yep, smooth skinning works with maps, as i said.

you can think of them as just black/white maps on the surface to describe the weighting. if you haven't layout your UV's (i mean for poly or subd, nurbs have already) its a big problem. it's the same issue if you would like to use the 3D Paint without laying out your UV's before. you paint on one point on the surface and you will get the same stroke on many other points, because the many UV's are lying in the same UV space.

[CAAB]

Originally posted by svenip
yep, thats definitly a problem. because smooth is working with maps which require UV's. now you didn't layout them, they are lying on top of each other and if you paint one piece of your skin it affects many parts, because their UV's lying in the same space.

That makes sense. Weird how I've never heard of that and Maya's manual made no mention of it that I can remember.

So I simply need to arrange the UV's? Is there a specific type of UV mapping that would work best for the smooth skinning?

[svenip]

doesn't matter what kind of UV Layout you're doin. just lay them out :)

you could simply do an automatic mapping. this would cut all and playe it in a few shards automaticly in UV Space. but this will be very hard to texture for you after all.

[CAAB]

I won' t be texturing, so any type of mapping is okay.

I fixed the UV's now, I think:

new file (http://www.cgocable.net/~cbecks/GI2.zip)


Should this change anything about the initial result when smooth skinning, or simply make it easier to paint weights?

[svenip]

it makes it really possible to paint :)

i will look at it tomorrow

[CAAB]

With my UV's re-arranged, I still get polys jutting out when I use the paint weights tool. I'll wait till you have a look at the UV's.

[CAAB]

And happy birthday, svenip :beer: .

[Waboflex]

The birthday might explain it... they shouldn't have let him near a computer :p

Um... I think svenip's been drinking with those deamons he's drawn... :scream:

What he's saying is good advice but you don't need good UV mapping to be able to use smooth skinning. You do need good UV's if you want to export and import weights, paint things and texture stuff. But not for skinning. That's all done on the vertices positional data, nothing to do with it's UV's. Ooo... in fact the UV data is a subset of it's vertex positional data blah blah blah... :rolleyes:

Honest. UV's don't make a toss of a difference when you're skinning a mesh.

Wabo.

[svenip]

uhhm, haven't thought of it :D sorry

[svenip]

so i'm on the run to weight the thing. i'll do this through a wrap def, to keep it animatable for you. so far nor problems.

a while ago i've posted the way i'm doin weighting. so here's the link to the thread

http://www.cgtalk.com/showthread.php?s=&threadid=12129&highlight=skinning

[ReD_MeRkIn]

I'd like to see how you handle this,
i've been using Conect Poly Shape, which when you bind it esentially works the same as a wrap deformer.

svenip :
i'd really like to hear how you solve your smooth skin weighting issues.

Red

[svenip]

as i mentioned in the thread i posted above i start out on the fingers. as he don't wanna have finger control (at least there are no bone available for that in the file) this means starting at wrist. i paint till it fits to the rotation down. normally you can't do it all just by weighting. for the different directions (the same for the elbow, shoulder etc) you may need to setup deformers driven by a SDK to deform the skin in the right way. so i start at the wrist till it fits and then toggle hold weights to keep me from destroying this weight if i paint further. so next is the radial/ulna, then elbow and shoulder. everytime i'm satisfied i hold the weights. then the same for the legs. start at the furthest point and keep goin to the inner body.

last part here is the body (he has no had). so i'm already finished with that because of the wrap deformer it goes straight forward and very fast. (just for an easy example like this without fingers etc). i have to setup a few deformers to get the right look, but that's all i do.

[CAAB]

Do you paint with normalization on, svenip?

And out of curiosity, what bind settings did you use?

[svenip]

when i "paint" i leave definitly the normalization on. from time to time i have to go into the component editor to fix some weightings per hand of some vertices. then it's time to switch it off, to have greater control. but always be aware that you've get a 1 on all weights together.

as for the binding settings i often use max 3 influences. most of the time there are no more in a character. and the less you have the less work you have. for your once i used the 3. for your purposes you have some bones in it without a use. the ribs are not necessary here. of course for a good character there are cool, but for you as a beginner they stand just in your way.

[ReD_MeRkIn]

what kind of defromers do you use, and where do you tend to use them? (elbows, knees sholders?)
thanks

[svenip]

the sculpt deformer with the flip mode and clusters of course. i use it everywhere, where the creature looses volume or it can't just be done by weighting alone.

these are indeed the knees, wrist etc. many places. but i don't put them anywhere in masses. :)

[CAAB]

I'm still having problems with the fact that the weighting of every vertex needs to amount to 1.

I understand why it has to be that way, but then how does one handle areas that just need a little influence from a joint? For instance, the area below the shoulder joint on my character needs just very light influence from the shoulder. So, with the paint weights tool, I reduce the joint's influence there. But I don't want the elbow or clavical joint, or any joint for that matter, to gain influence over the area. How do I handle this?

If I hold the weights of every joint after I'm done painting, won't there be vertices that don't have a total influence of 1? What happens then?

[Jhonus]

Originally posted by svenip
the sculpt deformer with the flip mode and clusters of course. i use it everywhere, where the creature looses volume or it can't just be done by weighting alone.


how do you overcome double transforms when you use clusters?

Sculpt deformers are essential... i've been using them to maintain the forearm shape when it is rotated.

They are also perfect for good biceps if you make the scaling of the sculpt deformer controlled by the elbow rotation.

CAAB:
I tend to have a couple of joints that don't do much, so i can dump unwanted weights onto them.

Its also good to rotate the joint to its relevant extremity and edit the weights from there until it looks proper. For this reason I use the component editor, because 1) you can see the deformations properly when its not black and white, and 2) i like seeing things mathmatically, and if i want to increase the vertices weight by .05 i can do it easily and quickly using the component editor.

Does everyone do that? (rotate the joint then weight it)

Also CAAB, you will know when a vertex doesn't have a 1 total weight (try it out). It will shoot off into space. So you'll see the problem the instant it happens and will be able to fix it.

[svenip]

in the options for the cluster is a checkbox "relativ" switch it on and then you can parent your cluster under the joint without getting double transforms.

to the extra joints for collecting weights :

you still have them in any skeleton. the last joints in every branch are always "void". mean that they do nothing. the deformation comes from rotating (at least it should) from the joints. as you don't rotate them ever you ca use them for collecting if you need.

yep sure i rotate them to the extreme positions to weight them. as i said you probably never come along with weighting alone to get everything right. that's why we have these nice deformers in maya :)

[CAAB]

Thanks...

I tend to have a couple of joints that don't do much, so i can dump unwanted weights onto them.

So is it a solution to have all the weights locked except for those joints that don't really serve a purpose? I suppose Maya would automatically dump the extra values for normalization onto those weights.

I wonder how other programs handle character skinning. I'd like to be able to complain about Maya's skinning tools, but I can't do so justifiably till I've used other packages :).

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