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Myles
Posts:
11
Registered:
6/14/12


Reposition 3D plane slice
Posted:
Jun 14, 2012 2:14 PM


"Matt J" wrote in message <jrd7ph$a7s$1@newscl01ah.mathworks.com>... > "Myles" wrote in message <jrd713$67g$1@newscl01ah.mathworks.com>... > > Hey  so I'm having troubles with what I think is a linear algebra related problem. > > I have a set of points taken from the intersection of a 3D model and 3D plane, I have replotted only the 3D intersection points and have them separated in a specific cell. Anyways, what I would like to do is take this angled plane in 3D and simply reposition the points so that they all lie in the xy plane  but as they would look when viewed from the normal of the plane. Almost like rotating every point a certain amount so they all lie in the xy plane and are no longer a 3D set. I'm not sure how to do this, I've been reading up through linear algebra textbooks and thought that transition matrices might work  but I'm not sure how basis vectors for the xy plane could be used to represent a 3D image with a z component. Any help would be greatly appreciated! Thanks. > ================== > > Using this FEX file > > http://www.mathworks.com/matlabcentral/fileexchange/308643drotationaboutshiftedaxis > > you can rotate all the points into the xyplane as follows > > u=cross(Ztilt, [0 0 1]); > deg=asind(norm(u)); > > NewPoints = AxelRot(YourPoints, deg, u);
All of that seems like it would perfectly  only one thing I don't understand, what do you mean by Ztilt? I get that all of that code is to find the angle between my plane and the xy plane  but I'm not exactly sure how you're meaning to do it. Either way, I appreciate the fast and helpful response!



