Revealing HiddenSurfaces

*To*: mathgroup at smc.vnet.net*Subject*: [mg4479] Revealing HiddenSurfaces*From*: dsmith at psy.ucsd.edu (David Smith)*Date*: Mon, 29 Jul 1996 02:37:30 -0400*Organization*: Univ. of California, San Diego*Sender*: owner-wri-mathgroup at wolfram.com

(I'm not sure whether this message made it to the group when I sent it first, so I'm reposting it. Cheers.) Could someone help on this? Thanks. I want to plot two things in a single 3D graph. One thing is just a surface which I can do easily enough as ... model = Plot3D[(x + y)/2, {x,0,25},{y,0,25}, PlotPoints -> 2, Shading -> False, HiddenSurface -> False] where I can see the hidden surface. Superimposed on this I wanted data points (where the `error` distance between each data point and the model surface is shown by a vertical line). I did this in two steps. First make the error lines with the example set ... data = Show[Graphics3D[{Line[{{0,1.97,0.98},{0,1.97,0.99}}], Line[{{0,8.72,4.02},{0,8.72,4.36}}], Line[{{0,22.1,8.38},{0,22.1,11.05}}]}, Axes -> True]] Finally plot everything together. Show[data, model, Shading -> False] The problem is that I`m unable to make the model surface transparent so that I can see the error lines of the data points behind the surface. Unfortunately Graphics3D doesn`t have a HiddenSurface option (Plot3D and Show do). Is there some way of doing this (maybe converting data to some other kind of graphics object)? This has been bugging me and I would really appreciate some pointers. Thanks. David dsmith at psy.ucsd.edu ==== [MESSAGE SEPARATOR] ====