Re: Q: Graphics3D

*To*: mathgroup at smc.vnet.net*Subject*: [mg13396] Re: [mg13320] Q: Graphics3D*From*: "Jens-Peer Kuska" <kuska at linmpi.mpg.de>*Date*: Thu, 23 Jul 1998 03:32:39 -0400*Sender*: owner-wri-mathgroup at wolfram.com

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 Subject: [mg13396] [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) > >