 | | Re: Mathematical assistance please
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In lugnet.cad.dev, Ross Crawford wrote: <snip> (...) know how to come up with the rotation angle needed to twist the 4-4cyls.dat into the right position. One reason to push forward on my original solution is because the same knowledge can be used to (...) (20 years ago, 6-Jan-05, to lugnet.cad.dev)
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| | Re: Mathematical assistance please
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(...) Could you transform the co-ordinate system so that one of it's axes is along the centre-line of the 4-4cyls (in the plane S0-S1-S2), rotate it about that axis so that the longest sise is in the plane, then transform the co-ord system back? (...) (20 years ago, 6-Jan-05, to lugnet.cad.dev)
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| | Re: Mathematical assistance please
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(...) Or maybe another way to look at it (got this from old lecture notes): Goal: rotate about arbitrary vector A by alpha Idea: we know how to rotate about X,Y,Z So, rotate about Y by beta until A lies in the YZ plane Then rotate about X by gamma (...) (20 years ago, 6-Jan-05, to lugnet.cad.dev)
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| | Re: Mathematical assistance please
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(...) Ooooops, I see now I was totally barking up the wrong tree, you need to WORK OUT the alpha angle, sorry. But transforming the co-ordinate system should still work. ROSCO (20 years ago, 6-Jan-05, to lugnet.cad.dev)
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| | Re: Mathematical assistance please
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(...) OK, here's my VERY LAST word on the subject: Transforming both 4-4cyls S0-S1 and vector S1-S2: Rotate about Y by beta until S0-S1 lies in the YZ plane Rotate about X by gamma until S0-S1 coincides with +Z Rotate about Z by delta until S1-S2 (...) (20 years ago, 7-Jan-05, to lugnet.cad.dev, FTX)
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