CGTalk - IK solver & Point Helpers problem...

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insanelight

08-05-2002, 08:16 AM

Hi.
I'm setting up my character with bones, but I have a little/strange problem with Point Helpers for his arm: :wip:

First of all I create an IK Chain from che UpperArm Bone to the Wrist Bone, then I put a Point Helper on the LowerArm Bone and move it back to define the Elbow dynamics. After that I set the Elbow Point as TARGET for the IK Chain (Pick Target button in the IK Chain motion rollout)... and I got this problem: all the arm bones rotates of 90°! So the all bones exits from the mesh! :surprised
Someone have idea why this happen? Please help me! :shrug:

Thanks

DanielWichterich

08-05-2002, 11:11 AM

i am not so sure about this stuff but: does the Elbow Point have the same local orientation as the arm bones?

insanelight

08-05-2002, 12:42 PM

Mh... I can't understand what you mean...
I'll post 2 shot of the wired scene as soon as possible, so we can better understand the problem and solve it (I HOPE) :bounce:

Thanks, if someone have opinion... I'm here.

insanelight

08-05-2002, 05:57 PM

Ok, I made 2 shots to show you my problem:
As soon as I set the Elbow Point as IK Chain Target the arm bones flips of 90°!

HELP HELP !!! my god, my brain is smoking... :surprised

http://www.insanelight.com/images/gallery/wip/mascotte/Capture_IK_1.jpg

http://www.insanelight.com/images/gallery/wip/mascotte/Capture_IK_2.jpg

Triadis

08-05-2002, 07:18 PM

It looks like the arm bones are too straight. Try bending the arm at the elbow before creating the IKchain(Animation > HI Solver). You can bend the arm at the elbow by grabbing the wrist bone and moving it forward a little.

Then go ahead and pick the point helper for the swivel control.

This seems to be the problem. Hope this helps.

-Alex

insanelight

08-05-2002, 08:47 PM

Hey!
Many thanks Triadis, You solved my problem! :thumbsup:
The bones are so straight because my model have the arms straight... at this point I have to come back again and modify the angle at the elbow level... :wip:

Many thanks again man! :beer:

Triadis

08-05-2002, 09:30 PM

Cool. :D I'm glad I could help.

Keep in mind that you don't have to bend the elbow too much. Just enough that there is a little kink. So I always make the model's arm so that it's slightly bent. This gives a more natural flow to the arm also.

:)

-Alex

pete

08-07-2002, 02:48 AM

Hey,

I had that problem as well, but I figured out why....
If you create a point object in any view but TOP it will actually be rotated 90 deg on one or more axis. You can see this down the bottom of the max screen when you are in rotate mode (where it says X,Y,Z).

Either set it to 0 there before you link or create the point helper in TOP view.

Good Luck

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