Subject:
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Re: Rotation of Systems
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Newsgroups:
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lugnet.cad.dev
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Date:
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Fri, 20 Sep 2002 20:49:39 GMT
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Viewed:
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507 times
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In lugnet.cad.dev, Orion Pobursky writes:
> Here's a clarification of my question:
>
> I'm creating a minifig generator plugin for LDDesignPad (possibly a stand
> alone version as well). I'm having trouble rotating the arm,hand,tool
> assembly about the origin of the arm. Using an inline procedure might work
> but I'm not quite sure how to do this. The problem is that I can rotate the
> hand and tool correctly but my procedure for determining the new position is
> faulty. Any help would be greatly appreciated.
Lets try it with vectors.
Calculate the vector V from the arm origin to the hand origin.
Rotate this vector about the arm origin (by angle A) to generate vector W.
Subtract V from W to generate displacement vector X.
Add the displacement vector X to the origin of the hand.
Rotate the hand about it's own origin (by angle A).
Rotate the the arm about its own origin (by angle A).
Everything should be in the right place?
Alternatively, this is pretty standard stuff. Just about every 3D
graphics book has an example of matrix concatenation for modeling a
robot arm. You can also find the same content all over the internet.
Does this help?
http://www.gamasutra.com/features/20020510/johnson_pfv.htm
If not, I suppose you could post the code you're working on (or put
it somewhere accessable) and we could point out what's wrong. You
could also examine the source for LDAO or Leocad, both of which already
include some sort of minifig modeler.
Good luck,
Don
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Message has 1 Reply:
 | | Re: Rotation of Systems
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| (...) Actually, if I remember right, the Minifig Modeler in LDAO uses LDLite statements for placement and rotation. Of course, it's been awhile since I was in that code, so I could be hallucinating... 0 TRANSLATE <to end of arm> 0 ROTATE <wrist into (...) (22 years ago, 26-Sep-02, to lugnet.cad.dev)
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Message is in Reply To:
| | Re: Rotation of Systems
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| Here's a clarification of my question: I'm creating a minifig generator plugin for LDDesignPad (possibly a stand alone version as well). I'm having trouble rotating the arm,hand,tool assembly about the origin of the arm. Using an inline procedure (...) (22 years ago, 20-Sep-02, to lugnet.cad.dev)
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