RE: tracing lines on surface-graphics

*To*: mathgroup at smc.vnet.net*Subject*: [mg25600] RE: [mg25593] tracing lines on surface-graphics*From*: "David Park" <djmp at earthlink.net>*Date*: Wed, 11 Oct 2000 03:50:39 -0400 (EDT)*Sender*: owner-wri-mathgroup at wolfram.com

Dear Alan, Here is a sample f[x,y]: f[x_, y_] := 1/(0.2 + (x/8)^2 + (y/8)^2) Here is your curve on the surface. I have raised the curve slightly so it won't intersect the surface. curve[x_] := {x, 1 + x/2, f[x, 1 + x/2] + 0.02} This is how to plot the two objects using the regular Mathematica plotting paradigm. g1 = First[ Graphics3D[ Plot3D[Evaluate[f[x, y]], {x, -10, 10}, {y, -10, 10}, PlotPoints -> 51, Mesh -> False, DisplayFunction -> Identity]]]; g2 = First[ ParametricPlot3D[Evaluate[curve[x]], {x, -10, 10}, DisplayFunction -> Identity]]; Show[Graphics3D[{g1, g2}, DisplayFunction -> $DisplayFunction]]; This is how to do it using the DrawingCube packages available at my web site. Needs["Graphics`DrawingCube`"] Needs["Graphics`ParametricDrawing3D`"] Show[Graphics3D[ {Draw3D[Evaluate[f[x, y]], {x, -10, 10}, {y, -10, 10}, PlotPoints -> 51, Mesh -> False], ParametricDraw3D[Evaluate[curve[x]], {x, -10, 10}]}]]; David Park djmp at earthlink.net http://home.earthlink.net/~djmp/ > -----Original Message----- > From: Alan Wetherby [mailto:roommate222 at my-deja.com] To: mathgroup at smc.vnet.net > > Hi - I can't find an obvious way to trace a line on a surface-graphics > object. I've plotted f(x,y) and got the surface I want, and now I want > to add a curve, say: x varies according to the plotted range, y=1+x/2, > z=f(x,y) --so it lies on the surface I've plotted. I've turned the mesh > off because it's too dense, given the number of points I'm plotting, > but I want to add a couple of such lines - another option would be to > trace every 20th mesh-line or something like that, but that doesn't > seem to be possible either. > > Thanks for any help -- Alan