 | | Math Problem Again
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| You are given three 3d cooridates. This makes a triangle in 3d space. The z values may all be three different, so it may be rotated in almost*) any direction. I am just interested of the plane; the surface it makes. Now, we have a forth point, with (...) (21 years ago, 13-Nov-03, to lugnet.cad.dev)
| | | | | Re: Math Problem Again
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| (...) (URL) you how to derive the equation of a plane passing thru the three points (x1,y1,z1) (x2,y2,z2) (x3,y3,z3) The standard equation of a plane in 3 space is A.x + B.y + C.z + D = 0 (where the "." means times) So given three points in space (...) (21 years ago, 14-Nov-03, to lugnet.cad.dev)
| | | | | Re: Math Problem Again
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| In lugnet.cad.dev, Ronan Webb wrote: 8<------ (...) Yes, it's very late. I'd better get myself some sleep first, and have a look at it tomorrow. Thanks a lot! /Tore (21 years ago, 14-Nov-03, to lugnet.cad.dev)
| | | | | Re: Math Problem Again
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| (...) Hey! cool! where was this info when I wrote my calculator program? It would have made it alot easier. The calculator grew into a slightly different purpose though. it was for helping determine where to trim lines and quads at intersection (...) (21 years ago, 14-Nov-03, to lugnet.cad.dev)
| | | | | Re: Math Problem Again
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| (...) Yes, I saw that, too. (...) Thanks for the offer, but I have already made a working spreadsheet. :) Now, all I have to do is try to automate it with some VBS. /Tore (21 years ago, 14-Nov-03, to lugnet.cad.dev)
| | | | | calc_z4.c (Was: Math Problem Again)
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| (...) Sorry guys, just wanted to store this function in a safer place than my hard drive. :) I just don't want to remake it again...! Feel free to copy/paste/edit/port if you need it! /Tore // calc_z4 by Tore Eriksson // credits to Ronan Webb for (...) (15 years ago, 22-Oct-09, to lugnet.cad.dev)
| | | | | Re: calc_z4.c (Was: Math Problem Again)
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| (...) You also need a touch of code to catch when c=0 so that z4 is undefined ;) Tim (15 years ago, 23-Oct-09, to lugnet.cad.dev)
| | | | | Re: calc_z4.c (Was: Math Problem Again)
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| In lugnet.cad.dev, Timothy Gould wrote: // calc_z4 by Tore Eriksson // credits to Ronan Webb for the superb formula double calc_z4(double x1,double y1,double z1, double x2,double y2,double z2, double x3,double y3,double z3, double x4,double y4) { (...) (15 years ago, 23-Oct-09, to lugnet.cad.dev)
| | | | | Re: calc_z4.c (Was: Math Problem Again)
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| (...) Actually, if the original triangle is (for example) in the Y-Z plane, then just passing in an x4 that's different from x1, x2, and x3 will result in a failure. The equivalent goes for an initial triangle in the X-Z plane. --Travis (15 years ago, 25-Oct-09, to lugnet.cad.dev)
| | | | | Re: calc_z4.c (Was: Math Problem Again)
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| (...) True, but such triangles will not be visible in the 2-D front view of the UI and therefor not clickable - unless the program is buggy. And if you can't click on them, the function never has to encounter data from them. Hopefully... /Tore (15 years ago, 26-Oct-09, to lugnet.cad.dev)
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