CGTalk - Problem with backhoe ik setup

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TeKnO

01-15-2005, 05:09 PM

Hello everybody!

I'm modelling a backhoe loader, but i'm having quite some problems to setup the IK/constraints, since i'm not that experienced with the latter.

As for now, i've managed to get most of the stuff done (aire pressured cylinders on both 'arms' with look-at constraints, etc.). I'm not sure if that's the best way to do it though.

The part where i'm having problems is the last one in the hierarchy (within the red circle). The black "scoop" is 'physically' attached to 2 different parts, and the proper behavior it should have is faked in the top right picture. I haven't managed to make it rotate and respond to both joints at the same time :(

I'm also posting a link to the max file.

I'd be very grateful if any of you guys could help me on this, since i'm in a big hurry :(

Thank you in advance :)

http://www.teknoart.com/stuff/backhoe/backhoe.gif
http://www.teknoart.com/stuff/backhoe/backhoe.max

3dRaven

01-16-2005, 07:44 PM

Ok I've fixed it. I'll throw a couple of gifs to explain how it's done

3dRaven

01-16-2005, 08:32 PM

http://members.lycos.co.uk/krajczyk/scoop.gif
http://members.lycos.co.uk/krajczyk/schematicview.gif
http://members.lycos.co.uk/krajczyk/backhoe06.max
The file is for max 7

SkullboX

01-16-2005, 08:57 PM

Raven's solution will work, but it's pretty complicated compared to what I had come up with.

The only alteration I made was move the pivot point of the scoop to the other joint (check pic), that wrongly placed pivot point was the reason you had problems figuring it out. Raven also placed the pivot there but didn't mention it. I added the two bones because the when I assigned an HI IK solver to the linked geometry the orientation got all weird, and I didn't feel like figuring that out. If you do, you don't need any bones.

Then I just linked everything to the appropriate bones and objects and added Look-at constraints to the pistons. Everything works and the file I uploaded has a little 'animation' to demonstrate.

3dRaven

01-16-2005, 09:04 PM

Yup sorry bout the pivot....tired haven't slept well for days. Wow SkullboX nice fixup. It beats mine hands down :thumbsup:

TeKnO

01-16-2005, 09:20 PM

Thank you so much guys! :thumbsup:

I was really stuck with this problem. As i've already told, i'm not that familiar with *advanced* ik/constraints setups.

I owe you a beer :)
:beer:

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