Re: Light and surface colors
- To: mathgroup at smc.vnet.net
- Subject: [mg58692] Re: Light and surface colors
- From: "Jens-Peer Kuska" <kuska at informatik.uni-leipzig.de>
- Date: Fri, 15 Jul 2005 03:02:09 -0400 (EDT)
- Organization: Uni Leipzig
- References: <db57t5$4vl$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
Hi, you have need a half-day for With[{a = 1, b = 2, c = 1/2}, ParametricPlot3D[ {a*Cos[phi]*Sin[th], b*Sin[phi]*Sin[th], c*Cos[th], Hue[phi/(2Pi)]}, {th, 0, Pi}, {phi, 0, 2Pi}, Lighting -> False] ] but wish With[{a = 1, b = 2, c = 1/2}, ParametricPlot3D[ {a*Cos[phi]*Sin[th], b*Sin[phi]*Sin[th], c*Cos[th], SurfaceColor[Hue[phi/(2Pi)]]}, {th, 0, Pi}, {phi, 0, 2Pi}] ] You can't have shadows in Mathematica. Even when you would be able to produce shadows, your scene has no floor or wall to show you the shadow You can try MathGL3d form http://phong.informatik.uni-leipzig.de/~kuska/mathgl3dv3/ and save the graphics to POVRay or Renderman and use these render engines to obtain light sources with shadows but you should add a floor or a box with solid walls in the back of the object. Regards Jens "Daniele Lupo" <danwolf_no_spam_please_ at libero.it> schrieb im Newsbeitrag news:db57t5$4vl$1 at smc.vnet.net... | Hi to everyone. | | I've just obtained a Student License of Mathematica, and I'm working in | graphics... | | I've created, after a half-day of work, an image representing an ellipsoid, | with a colored surface | | When I try to represent it, I must put Ligthing->False to see surface | colors. | | I'd like to know if there's a way to obtain a rendered image, in which I | can have both light and surface color, to give a shadow to the figure and | create a more 3D effect. | | Thanks for replies. | | Below there's the code... | | | Daniele | | | -------------------------- | | << Graphics`ContourPlot3D`; | | a = 7; b = 5; c = 4; r = 1; | | ellipsoid = ContourPlot3D[ | (x/a)^2 + (y/b)^2 + (z/c)^2 - r, { | x, -10, 10}, {y, -10, 10}, {z, -10, 10}, | PlotPoints -> 12, | AspectRatio -> Automatic | ]; | | (*It finds the median point of vertices of a list of a 3D coordinates*) | midpoint[l_] := Apply[Plus, Transpose[l], 2]/Length[l]; | | | (*Function to map in the ellipsoid surface*) | pressure[x_, y_, z_] := x^2 + y^2 + Sin[4z]; | | (*Color Function*) | color[x_] := Hue[pressure @@ midpoint[x]/50]; | | (*Rule to change original graphic object*) | colorpolygon = Polygon[coord_] :> | {color[coord],EdgeForm[{}],Polygon[coord]}; | | (*creation of new, colored ellipsoid*) | coloredellipse = ellipsoid /. colorpolygon; | | (*Visualization of the shape*) | (*I'd like to have also the light...*) | Show[coloredellipse, Lighting -> False]; |