Maya for 3D Printing - Rapid Prototyping
In this course we're going to look at something a little different, creating technically accurate 3D printed parts.
# 1 08-11-2005 , 07:00 PM
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foot rig

Some of you might remember that I did a T-rex project earlier this year. I modeled the REX using Kurt's tutorial then rigged it, painted it and animated it. The animation was pretty bad but what really bothered me is that I could never come up with a good foot rig so that the toes could curl under as the beast lifted it's foot to take the next step. The leg used an IK solver and the foot used a standard type "reverse foot" rig. This kind of a set up works well if you're doing a character with shoes on or something like that but I wanted the toes to curl under like the CGI Godzilla in the movie. With a reverse foot rig it's easy to make the foot rotate from the ball but when the foot comes off the ground, there was no way that I could discover to rotate the toes in, almost like it was making a fist with its toes.

My T-rex animation

So, are there any riggers out there who could throw a clue my way?

I did build one rig that allowed the foot to do everything I just described but the problem was that it was controlled with MEL scripts. I need to find a way that is able to be key framed. The MEL scripts worked just fine for reversing the Heirarchy of the joints in the reverse foot rig so that I could have the toes bend in either direction (rotate + or _ around the X axis)but you could not rewind and play back the animation since there were no keyframes. The foot would twist and do all sorts of weird things.

Any thoughts?

user added image


Last edited by Velusion; 08-11-2005 at 07:04 PM.
# 2 09-11-2005 , 09:33 AM
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Sorry i dont know how you could do that easily, you could do it with making each little toe have its own joints, and then for each foot make a control center with an abbtribute that cruls all the toes in, sorry I cant really help cause im new too rigging, and Maya in general.

However! your animation is great!! How did you get it to look like its in that street? Its creepy as hell!


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# 3 09-11-2005 , 01:31 PM
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dylanjones,
LOL! I think you're the second person who thought the rex walking in the street looked creepy.

I made a lot of mistakes with the compositing but I have a brief explanation of how I did it
here

I wanted to raytrace the shadows but, for some reason, half way through the project the raytracing stopped working so I ended up using shadow maps. I also learned that animating is harder than I thought.

# 4 09-11-2005 , 08:05 PM
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Thats awesome! Thanks that compositing part really helped me understand how to use matte paintings in mayauser added image


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# 5 09-11-2005 , 09:09 PM
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This little icon demonstrates what it was like trying to do that composition :headbang:


Last edited by Velusion; 09-11-2005 at 09:13 PM.
# 6 09-11-2005 , 11:10 PM
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lol, that site of yours is amazing! your amazing at that modeling with clay/plastic stuffy foam.

If your still interested in getting a sweet foot rig, I could send you some stuff that could help you! If your interested, tell me your email, and I willl sendy!


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# 7 10-11-2005 , 12:54 PM
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dylanjones,

Am I interested?! Hell yeah. :attn: Thank you!!

Here's my E-mail: James@morphicmotion.com


I've been running new ideas through my brain ever since I sort of failed with my foot rig last year but now I'm ready to sit down and figure this thing out.

By the way, here's a link to a video clip that show the foot rig I came up with last year. The whole thing is based on the ability of a mel script that I wrote which reverses the hierarchy of the foot rig. Like I said before, it works well for posing and manipulating the foot but it doesn't keyframe anything so you can't play back the moves.
foot rig

# 8 10-11-2005 , 10:54 PM
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Ok I sent you email user added image

I said Toe_Rot_X, but I think it would be better if you used the ball of the foot instead of the toe, but I think you could get it working!

Best of luck!


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# 9 16-11-2005 , 10:39 AM
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Not quite sure did I catch all that you said, but I'll try to explain:

By the way sorry for bad english and bad pics...I am at work so I dont have Maya aveliable to test this idea.

So here it is:

Attached Thumbnails

ICQ:215-024-460
# 10 16-11-2005 , 01:21 PM
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The thing is, having a reverse foot rig allows you to rotate the toes on the X axis and the leg will move (through IK) but the foot will stay firmly planted on the ground. That is step one. No problem there...

The next thing is that the toes, which are being controlled by a reverse foot, now have to curl under. The reverse foot can not do that. My solution was to reverse the reverse foot with a mel script so that it becomes a forward foot. As I said; it worked fine for posing the model but the reversing of the foot rig heirarchy was not keyframable for animation.

I guess a good question would be; is a reverse rig so important? Are there other ways to keep the foot planted during a walk cycle?

Anyway, I have some new tutorials and other information to go through that will hopefully shed some light on this problem. It's not just feet we're talking about either. Think of Spiderman when he climbs up a wall. He puts his hand on the wall then moves upward but his hand doesn't move. Either the animator keyframed it very carefully or he/she had another way to make sure that it didn't move.

# 11 16-11-2005 , 02:32 PM
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Wait...when I'll get home I'll try to construct the rig and then post it here!


ICQ:215-024-460
# 12 16-11-2005 , 11:51 PM
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Ok, here's the foot rig.

Quite messy,15 IK SC and 1 RP solver, 100 unamed groups but you just click on foot control behind the heel.
You'll see attribute Foot_Thoes_Curl-->drag middle mouse button in negative to curl toes under.

The foot is not done I didnt have time to finish it-->note when you rotate Foot control around X axies it rotates the whole foot but not around the heel down to the toes.

Anyway, you shouldnt have any problems curling the thoes down.

I hope I helped, note me if you have any suggestion or a problem I would be glad to help or hear your opinion!

Attached Files
File Type: mb trexfootsetup1.mb (70.3 KB, 326 views)

ICQ:215-024-460
# 13 17-11-2005 , 12:31 PM
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OK. I'll check i t out tonight when I get home. From your description of it, I think it will do the trick. Thanks for taking the time to do this. I'll return to this thread once I check out the rig.

Thanks again...

# 14 18-11-2005 , 04:55 PM
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The rig works very well. In the next couple of months, I'll build one of my own using yours as a guide then I will attach a skin to it, create an animation cycle then post the results here.

Thanks again :bow:

# 15 19-11-2005 , 04:31 PM
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Glad I could help!

Watch joint orientatinon, mine wasnt good on the toes, and connect groups with ankle so you can have control over the rotation...a lot can be done just by grouping and moving pivots!

Bye


ICQ:215-024-460
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