Problem Rigging/Skinning arm/shoulder in 3D S Max
Hello!
Today is my second try Skinning-Rigging a character in 3D Studio Max.
I'm using a biped and the skin modifier, I've edited a bit the envelopes and manually changed the weights on some vertex and also I animated the biped to test it.
This is the result:
So far there are critical ugly deformations in the shoulder that I cannot get rid, no matter what I try. I'm searching for tutorials and I cannot find anything about it. I also would like to know how do they rig/skin for animated films, and also for games( it may be different methods). I hope someone can help me find a way to get rid of these deformations.
Thank you so much in advance.
Today is my second try Skinning-Rigging a character in 3D Studio Max.
I'm using a biped and the skin modifier, I've edited a bit the envelopes and manually changed the weights on some vertex and also I animated the biped to test it.
This is the result:
So far there are critical ugly deformations in the shoulder that I cannot get rid, no matter what I try. I'm searching for tutorials and I cannot find anything about it. I also would like to know how do they rig/skin for animated films, and also for games( it may be different methods). I hope someone can help me find a way to get rid of these deformations.
Thank you so much in advance.
Replies
All of the joints that rotate on multiple axes are tough to skin, (hips, ankles, wrists, shoulders, especially shoulders). The shoulders are a little blocky (so are the elbows) but you should be able to get fairly decent deformation with what you have, at least better than what you have right now. Still if you can afford a few more polys you should add them to the joints, it will help, but won't solve your problem.
Biped has some limitations and some bonuses. One limitation is that it doesn't allow the clavicle to rotate on the X axis, that rotation can be very helpful in fixing some shoulder deformation issues in certain poses.
One bonus is that it has twist bones that can be applied to problem areas like the thighs, biceps, forearms, pretty much any joint that neighbors a multi-axis problem area . Twists help spread the wonky deformation down the rest of the joint, they aren't perfect but they do "help". To actually solve the problem you need to use some pretty advanced rigging which typically isn't used in game development, but the line between film and games is blurring.
Advanced rigging techniques to dream about:
Morph angle deformer
http://docs.autodesk.com/3DSMAX/15/ENU/3ds-Max-Help/index.html?url=files/GUID-94865877-0C04-4AC6-A01D-F0FD4BDFDD86.htm,topicNumber=d30e98377
These are part of 3dsmax's skin modifier. They are morph targets driven by the angle of the bones. This allows you to put the bones in a problem pose and then re-model the problem area to look like it should. Then as the bones near the target angle a morpher is turned on and blended in. This can really slow a lot of things down especially if you use more than a handful or have multiple running at the same time. Also this type of tool typically isn't supported by games. These can also go horribly wrong during animation when bones move in a certain way that trigger the morphs in bad ways, so not only are they slow but they can bite you in the ass and be hard to fix, still they are great when used sparingly for specific cases.
Dual Quaternion skinning
http://www.seas.upenn.edu/~ladislav/papers/sdq-i3d07/sdq-i3d07.pdf
This is supported by a handful of engines but normally under controlled circumstances, but Max currently has ZERO support for Dual Quat skinning. At least out of the box there are some scripts that you can get a hold of that do enable it but its not an easy task to get working and is even harder to export out of max. Dual Quat skinning helps combat the dreaded candy wrapper effect and helps hold volume a lot better, but it's a lot more expensive.
Bones Pro
http://www.bonespro.com/
This allows you to place helpers and deformers on the rig, these helpers can be moved, scaled and rotated to help deformation. Typically this isn't supported in games, or any other copy of max that doesn't have the plug-in, but it does REALLY help with skinning and deformation.
Muscle Simulation
http://docs.autodesk.com/3DSMAX/15/ENU/3ds-Max-Help/index.html?url=files/GUID-49276514-378F-4FDA-9B3B-E31E332DD966.htm,topicNumber=d30e285945
3dsmax has CAT Muscle and there are a handful of other muscle systems out there for max. CAT Muscle works with anything so check out the help files.
Muscles, can help with shoulder deformation and help that specific look of muscles flexing and relaxing as well as getting skin to slide over muscle and bone. This is supported by some engines but is not widely adopted, yet or even a common practice but that was mostly due to hardware limitations on the PS3 and 360, ancient tech that is about to be replaced.
Still, even without all of those techniques you should be able to do better than what you have now. Make sure you have your weights assigned properly, add a bit more geometry and check out some resources.
Resources to check out:
http://www.hippydrome.com/Shldr.html
http://www.hippydrome.com/LShldrUDOnOffTargets.html
Thanks a lot!!!
I'm going to read, right now, everything that you've suggested, specially about CAT muscles. All those rigging tecniques sound great, I didnt know about them!
I'll try to use my higher poly version of the character. I dont get why its so deformed either... and I also feel that it should not look so bad. I'll check againg the skinning.
Do you think it could be better to try and use Bones instead of Biped?(I dont know much about Bones yet, but maybe I should study that too)
Btw, What do you use when you rig something that you are going to animate later? Is it Biped or is it something else?
Thankyou very much for all this useful information Mark
They really helped me. I didnt tried CAT before but decided to do so after reading your suggestion about CATmuscle. So I did the whole rig again but using CAT instead of biped and it worked really good. Right now I'm reading about CATmuscles, it looks promising.
I'll paste here a pic of the rig, its a quick rig I did not take much time with weights (still needs more work) but it looks quite good.
So, thanks^^
ridiculously well done guide on articulation, scour this mans website!!!!
Twist bones are the answer - I'll sacrifice almost any other bone to get them in shoulders if there's budget restrictions
The cunning methods above are great provided your target platform supports them but you'll find many don't.
CAT has been horribly unreliable in my experience (haven't touched it since 2012 so they might have fixed some of the horrors but still....)
Bones are great provided you know how to attach them together
If you're not interested in making a proper rig and merely want to pose a character I suggest you stick with biped because it does the maths (properly) for you. There are alternatives (puppetshop etc.) but unless you have a specific reason for using them it's not really worth the arseache/cost