RE: Drawing outline of 3D shape
- To: mathgroup at smc.vnet.net
- Subject: [mg67646] RE: [mg67628] Drawing outline of 3D shape
- From: "David Park" <djmp at earthlink.net>
- Date: Mon, 3 Jul 2006 06:38:07 -0400 (EDT)
- Sender: owner-wri-mathgroup at wolfram.com
Mark,
With DrawGraphics, from my web site, I would do it as follows:
Needs["DrawGraphics`DrawingMaster`"]
sphere[r_, t_, p_] := r{Cos[p]Sin[t], Sin[p]Sin[t], Cos[t]}
The following draws the outline around the equator and an upper half great
circle going through the North pole. I got that by drawing half of the
equator and then rotating it with the RotateShape routine.
Draw3DItems[
{ParametricDraw3D[sphere[1, Pi/2, p], {p, 0, 2Pi}],
ParametricDraw3D[sphere[1, Pi/2, p], {p, Pi, 2Pi}] //
UseRotateShape[0, Pi/2, Pi/2]},
Boxed -> False
];
The following is a variation where the equatorial plane is drawn as a solid
surface and a single upper arc is drawn in a light gray and the grid lines
faintly indicated.
Draw3DItems[
{SurfaceColor[Gainsboro], EdgeForm[ColorMix[Gainsboro, Black][0.2]],
ParametricDraw3D[sphere[r, Pi/2, p], {r, 0, 1}, {p, 0, 2Pi},
PlotPoints -> {5, 32}],
ParametricDraw3D[sphere[1, Pi/2, p], {p, Pi, 2Pi}] //
UseRotateShape[0, Pi/2, Pi/2]},
NeutralLighting[0.3, 0.5, 0],
Boxed -> False,
Background -> Linen
];
David Park
djmp at earthlink.net
http://home.earthlink.net/~djmp/
From: MS [mailto:mark.stankus at gmail.com]
To: mathgroup at smc.vnet.net
Hello,
Is there a program to draw the outline of a 3D shape.
So a sphere would be drawn as a circle.
A half sphere would be drawn as a arc (where the round
part goes from visible to not visible) and a circle (highlighting
the flat part of the half sphere.
Mark Stankus