Re: Q: Graphics3D
- To: mathgroup at smc.vnet.net
- Subject: [mg13441] Re: Q: Graphics3D
- From: "Allan Hayes" <hay at haystack.demon.cc.uk>
- Date: Fri, 24 Jul 1998 01:45:30 -0400
- References: <6p6p5s$5fs@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
Jens,
Just a little extra to your suggestion:
>Show[Graphics3D[
> {{SurfaceColor[RGBColor[1,0,0]],TranslateShape[Sphere[],{1,0,0}]},
> {SurfaceColor[RGBColor[0,1,0]],TranslateShape[Sphere[],{-1,0,0}]}}
> ]]
To avoid the spheres showing that the different colors are coming from
lights at different positions (defaults, LightSources
-> {{{1.,0.,1.},RGBColor[1,0,0]},{{1.,1.,1.},
RGBColor[0,1,0]},{{0.,1.,1.},RGBColor[0,0,1]}} )
We can, for example,can get the effect of a white light at {1.,1.,1.} by
placing all the light sources at this point:
Show[Graphics3D[
{{SurfaceColor[RGBColor[1,0,0]],TranslateShape[Sphere[],{1,0,0}]},
{SurfaceColor[RGBColor[0,1,0]],TranslateShape[Sphere[],{-1,0,0}]}}
], LightSources
-> {{{1.,1.,1.},RGBColor[1,0,0]},{{1.,1.,1.},
RGBColor[0,1,0]},{{1.,1.,1.},RGBColor[0,0,1]}}]
Allan,
-------------------------------------------------------------
Allan Hayes
Training and Consulting
Leicester UK
http://www.haystack.demon.co.uk
hay at haystack.demon.co.uk
voice: +44 (0)116 271 4198
fax: +44(0)116 271 8642
Jens-Peer Kuska wrote in message <6p6p5s$5fs at smc.vnet.net>...
>Hi Ulf,
>
>general to color surfaces You must use the SurfaceColor[] primitive. The
>following shows Your colored spheres:
>
>Show[Graphics3D[
> {{SurfaceColor[RGBColor[1,0,0]],TranslateShape[Sphere[],{1,0,0}]},
> {SurfaceColor[RGBColor[0,1,0]],TranslateShape[Sphere[],{-1,0,0}]}}
> ]]
>
>
>To question (1)
>The default surface color of Mathematica objects is white. AmbientLight
>is a undirected enviroment light, and if You look onto a white body
>with a red light it looks red. If You look at a white body with green
>light it looks green. Thats why You see a red and a green sphere in
>Your a and b graphics. If You combine two graphics objects the options
>for display are taken from the first graphics object. So the
>combination uses the red ambient light of graphics a and the two white
>spheres look red.
>
>Hope that helps
> Jens
>-----Original Message-----
>From: Ulf Saalmann <us at mpipks-dresden.mpg.de> To: mathgroup at smc.vnet.net
To: mathgroup at smc.vnet.net
>Subject: [mg13441] [mg13320] Q: Graphics3D
>
>
>>Hello,
>>
>>using the following functions
>>
>>-------------------------------------------------
>>Needs["Graphics`Shapes`"];
>>
>>SetOptions[Graphics3D,LightSources->{}];
>>
>>a=Graphics3D[TranslateShape[Sphere[],{+1,0,0}],
>> AmbientLight->RGBColor[1,0,0]];
>>b=Graphics3D[TranslateShape[Sphere[],{-1,0,0}],
>> AmbientLight->RGBColor[0,1,0]];
>>
>>Show[{a,b}];
>>-------------------------------------------------
>>
>>Mathematica shows two red spheres.
>>
>>
>>(1) Why I don't get a red and green one?
>>
>>(2) How to obtain a red and green one (with Lightning->True)?
>>
>>
>>Thanks for any help. Ulf (us at mpipks-dresden.mpg.de)
>>
>>
>
>