MathGroup Archive 1999

[Date Index] [Thread Index] [Author Index]

Search the Archive

Graphics3D and polygons

  • To: mathgroup at smc.vnet.net
  • Subject: [mg15802] Graphics3D and polygons
  • From: "Dr. Christopher J. Purcell" <purcell at drea.dnd.ca>
  • Date: Sun, 7 Feb 1999 02:04:17 -0500 (EST)
  • Organization: DREA
  • Sender: owner-wri-mathgroup at wolfram.com

This may just be finger trouble but I can't get nonconvex polygons to
plot correctly under Graphics3D with either V2.2 or V3.0. The only
reference I can find is
http://www.mathsource.com/Content/Applications/Graphics/2D/0209-854 but
it causes an unacceptable performance hit. Any faster fixes known? Here
is an example of the problem...

(2D polygon works fine - gives a red bow tie *)

Show[Graphics[{RGBColor[1, 0, 0],
Polygon[{{0,0},{50,25},{100,0},
{100, 100},{50,80},{0, 100},{0, 0}
}]}],AspectRatio->Automatic];

(* same polygon as above in 3D is drawn wrong *)

Show[Graphics3D[{RGBColor[1, 0, 0],
Polygon[{{0,0},{50,25},{100,0},
{100, 100},{50,80},{0, 100},{0, 0}
}/.{a_,b_}->{a,b,0}]},
ViewPoint->{0,0,10},Boxed->False,
RenderAll->True,
AspectRatio->Automatic]];



  • Prev by Date: Ploting Colored Error Bars
  • Next by Date: Re: List Position
  • Previous by thread: Ploting Colored Error Bars
  • Next by thread: Re: Graphics3D and polygons