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Topic: Reposition 3D plane slice
Replies: 16   Last Post: Jun 15, 2012 5:22 PM

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Myles

Posts: 11
Registered: 6/14/12
Reposition 3D plane slice
Posted: Jun 14, 2012 2:14 PM
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"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 x-y 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 x-y 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/30864-3d-rotation-about-shifted-axis
>
> you can rotate all the points into the xy-plane 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!



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