Sectioning Gizmo Drawing Objects

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I would like to section geometric objects, e.g. a sphere or more generally, polyhedra. I thought I could do this by generating drawing objects and then reducing the viewing box to very small zNear/zFar values, so I would look at a thin slice:

NewGizmo/I
AppendToGizmo/D sphere = {1, 100, 100}
ModifyGizmo operation = ortho, data={-1,1,-1,1,-0.1,0.1}


It turns out that drawing objects are "hollow", so instead of getting a disk, I get a ring. Can I "fill" 3D drawing objects or can I use a different method?
Hello ChrLie,

With few exceptions (e.g., points, lines), objects in Gizmo are represented by their exterior surface. If you have data for the interior of objects, you can attempt to draw it by painting the data on the clipping planes. For arbitrary "clipping" you will need to perform a lot of computation to draw and paint the appropriate surfaces (usually a parametric surface with color wave). That can be accomplished as you can see from the spherical brain example on the left.

Also, you may want to check the Clipping Demo Experiment under File Menu->Example Experiments->Visualization->Advanced.

A.G.
WaveMetrics, Inc.

June 4, 2014 at 05:17 pm - Permalink


Hi A.G.,

Igor wrote:
…. For arbitrary "clipping" you will need to perform a lot of computation to draw and paint the appropriate surfaces….


Unfortunately, arbitrary clipping/sectioning is the idea behind it ….I hoped, I could get around any geometric calculations that way.

Well, thanks anyway!
C

June 5, 2014 at 01:39 am - Permalink