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Fasty
04-20-2003, 02:44 PM
Hi I hope someone can help me with this awful problem. I'm doing my Challenge animation and I've come across this while trying to bend his wrists.

http://www.stu-art.net.au/cgchallenges/12_whoops/1.gif
http://www.stu-art.net.au/cgchallenges/12_whoops/2.gif

I knew this would come up, so I split the forearm bone in two just in case. The problem is, even when I try to compensate using the forarm bone, it still give an ugly result. The arm twists and goes skinny :cry:

http://www.stu-art.net.au/cgchallenges/12_whoops/3.gif

Is there any way I can overcome this problem, prefferably without disrupting any existing animation if possible (I've pretty much finished all the animation and there's not long until the challenge finishes)!

Please help me!!

CIM
04-20-2003, 08:52 PM
Fix your Weight Map.

twidup
04-21-2003, 01:14 AM
yeah, fix the weight map or change the way the forearm bones are done. YOu have 2 bones in the forearm. the writst shouldnt be doing any of that rotation, and thats actually an ok setup, but there are better...IE, run 2 bones back off the wrist to the elbow like the radius and ulna, and setup a short IK chain on those. that should solve the bubble gum wrapper effect.

SplineGod
04-21-2003, 02:29 AM
Originally posted by Fasty
Hi I hope someone can help me with this awful problem. I'm doing my Challenge animation and I've come across this while trying to bend his wrists.

I knew this would come up, so I split the forearm bone in two just in case. The problem is, even when I try to compensate using the forarm bone, it still give an ugly result. The arm twists and goes skinny :cry:

Is there any way I can overcome this problem, prefferably without disrupting any existing animation if possible (I've pretty much finished all the animation and there's not long until the challenge finishes)!

Please help me!!

Heres some things you can try:
1.Set you bone falloff to ^128 .
2. Split the forearm into 3 bones rather then just two.
3. Add some more cuts in the forearm to distribute the deformations better. This works better when you have more then two forarm bones. You can ADDITIVELY twist the forearm bones by selecting them at the same time and twisting. This helps to better distribute the twisting as well.
4. Increase the REST LENGTH of the forearm bone thats actually bending the forearm until its the length of all the forearm bones. Start to increase the bone strength. Do this in the twisted position. Youll be able to see the collapsing decrease. All bones should be active while you do this.
5. Use an endomorph to increase the size of the forearm to counteract the collapsing.
6. Try using a weight maps as a last resort. The reason is that you cant just add one weight map. Youll have to add at least two weight maps; one for the forearm and one for the rest of the mesh. You will also have to go and assign every bone to a weight map. So skip this unless none of the other suggestions work.

Fasty
04-21-2003, 09:19 AM
Thanks for the suggestions, I'll give them a try :)

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