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3D plotting normal displacement on surfaces

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When doing a 3-D plot, I want to illustrate how a c-library function I wrote, designed to generate rough surfaces via the Deformed Geometry (dg) module. I want to plot contours of the normal component of the displacement.

The displacement, defined over volumes, is : dg.dxx, dg.dyy, dg.dzz
The normal unit vector, defined (of course) over surfaces, is: dg.nXg, dg.nYg, dg.nZg

What's wanted is the dot product... but this requires sampling dg.dxx, etc, on the surface, where at present it is undefined.

Any hints?

Here's a plot of my surface, showing only dg.dxx, which is what I want only on faces normal to x-hat:
i.imgur.com/7EAVI4Z.png



2 Replies Last Post Sep 16, 2016, 3:10 p.m. EDT

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Posted: 8 years ago Sep 8, 2016, 5:01 p.m. EDT
For purposed of my present paper, I'm probably just going to plot the x-compnent, and put the x-normal face facing the "viewer". This has the advantage of maintaining color continuity around corners, something that would be lost if I involved the unit normal vector. Actually, since the surface must be continuous, my proposed normal component approach is in any case only an approximation.
For purposed of my present paper, I'm probably just going to plot the x-compnent, and put the x-normal face facing the "viewer". This has the advantage of maintaining color continuity around corners, something that would be lost if I involved the unit normal vector. Actually, since the surface must be continuous, my proposed normal component approach is in any case only an approximation.

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Posted: 8 years ago Sep 16, 2016, 3:10 p.m. EDT
I never got a reply to this question, and am happy for thus publication with just using the x-component of the distortion, although I'm still interested in how to select volume fields at surfaces.
I never got a reply to this question, and am happy for thus publication with just using the x-component of the distortion, although I'm still interested in how to select volume fields at surfaces.

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