Re: Mathematica bug in Graphics3D ??

• To: mathgroup at smc.vnet.net
• Subject: [mg22269] Re: Mathematica bug in Graphics3D ??
• From: "Allan Hayes" <hay at haystack.demon.co.uk>
• Date: Sat, 19 Feb 2000 23:50:57 -0500 (EST)
• References: <88juec\$9o3@smc.vnet.net>
• Sender: owner-wri-mathgroup at wolfram.com

```Axel:

Show[Graphics3D[
Polygon[{{2.5, Sqrt[3]/2, 0}, {3.5, Sqrt[3]/2, 0}, {4, Sqrt[3], 0}, {3,
2*Sqrt[3], 0}, {2, 2*Sqrt[3], 0}, {3, Sqrt[3], 0}}]], Axes -> True
]

Show the vertices  in  order  by numbers (change the z coordinate of the
last point sightly to get a better view)

Show[Graphics3D[{Text[1, {2.5, Sqrt[3]/2, 0}], Text[2, {3.5, Sqrt[3]/2, 0}],
Text[3, {4, Sqrt[3], 0}],
Text[4, {3, 2*Sqrt[3], 0}],
Text[5, {2, 2*Sqrt[3], 0}],
Text[6, {3, Sqrt[3], 0.1}]}], Axes -> True,
Ticks -> False,
TextStyle -> {FontSize -> 24}
]

In 3D Mathematica draws the triangles  {1,2,3},{1,3,4},{1,4,5},{1,5,6}.
I have not sorted out the rule for when edges are shown, but compare the
original picture with

Show[Graphics3D[
Polygon[{{2.5, Sqrt[3]/2, 0}, {3.5, Sqrt[3]/2, 0}, {4, Sqrt[3], 0}, {3,
2*Sqrt[3], 0}, {2, 2*Sqrt[3], 0}, {5, Sqrt[3], 0}}]], Axes -> True
]

Allan
---------------------
Allan Hayes
Mathematica Training and Consulting
Leicester UK
www.haystack.demon.co.uk
hay at haystack.demon.co.uk
Voice: +44 (0)116 271 4198
Fax: +44 (0)870 164 0565

"Axel Kowald" <axel at itb.biologie.hu-berlin.de> wrote in message
news:88juec\$9o3 at smc.vnet.net...
> Hello,
>
> I'm using Mathematica 4.0.1.0 under NT4 and when I try:
>
> Show[Graphics3D[Polygon[{{2.5, Sqrt[3]/2, 0}, {3.5, Sqrt[3]/2, 0},
> {4, Sqrt[3], 0}, {3, 2*Sqrt[3], 0}, {2, 2*Sqrt[3], 0},
> {3, Sqrt[3], 0}} ]], Axes -> True]
>
> Mathematica draws a polygon with only 5 corners where the last point
> {3,Sqrt[3],0} is missing. Am I doing something wrong here or what is
> going on ?
>
> Many thanks
>
> Axel
>
> --
> -----------------------------------------------------------------
> Dr. A. Kowald
> Innovationskolleg Theoretische Biologie
> Humboldt University Berlin
> Invalidenstr. 43
> 10115 Berlin
> Germany
>
> Email: a.kowald at itb.biologie.hu-berlin.de
> Phone: +49 30 2093 9105
> Fax:   +49 30 2093 8801
> -----------------------------------------------------------------
>

```

• Prev by Date: Saving as HTML -- Page width problems
• Next by Date: Re: Re: export graphics
• Previous by thread: Re: Mathematica bug in Graphics3D ??
• Next by thread: Re: Mathematica bug in Graphics3D ??