Re: Projective Geometry in a CAD Program

From: Bathsheba Grossman (
Date: Wed Apr 09 2003 - 04:11:53 EEST

On Tue, 8 Apr 2003, Jonathan Chertok wrote:
> A. Does anyone know of a CAD program within which one can conveniently do
> "projective geometry".
> I am hoping for a 3D program within which I can set up a couple of "planes"
> in order to project lines to create a 3D object from a series of elevations -
> or to create a series of elevations from a 3D object. I suppose an ability to
> snap to a plane and to create a perpendicular to this line would be useful.

Rhinoceros would work.

> B. Similarly, I am wondering if there is a program within which one might
> have a command "Project Outline" or "Find Points in this Section" which would
> yield information in the form of points or lines from which I could construct
> additional drawings.

> Here I am hoping for a 3D program which would allow me to construct a 3D
> shape - take sections or elevations of it - and then construct additional
> drawings using this "section" or "outline" information.

I am not really understanding what you want here, but Rhino has a
Project command which takes curves to a plane; it also has Intersect
and Contour commands for taking cross-sections through objects. It
does not easily produce 2D drawings, but I should think it would solve
the 3D part of the problem.


Bathsheba Grossman                 phone (831)429-8224, fax (831)460-1242
Sculpting geometry                                
Solidscape prototyping                           

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