http://grasshopper3d.googlegroups.com/web/extruder-test.3dm?hl=en&gda=MWYZ7kMAAAC19Ve3i4OoV9kZmG4Q4msc28Jgji3aggNflWX_hTxcJT2oLcM8Wl_0v2CvF1CNsIoytiJ-HdGYYcPi_09pl8N7FWLveOaWjzbYnpnkpmxcWg&gsc=-GSVMRYAAABMcOonFMD9x6vH0RzfJQjlg-kXU5InE09W2o0GCSVgCQ
http://grasshopper3d.googlegroups.com/web/extruder-test.ghx?hl=en&gda=XL8_nEMAAAC19Ve3i4OoV9kZmG4Q4msc28Jgji3aggNflWX_hTxcJf65xSx52VJD_6EgtgZubWYytiJ-HdGYYcPi_09pl8N7FWLveOaWjzbYnpnkpmxcWg&gsc=-GSVMRYAAABMcOonFMD9x6vH0RzfJQjlg-kXU5InE09W2o0GCSVgCQ Please take a look at the definition and rhino model I have provided. It is quite a simple definition but I am having some problems with the surface analysis. I am trying to use the surface as a guide for rotating extruded geometry. Here's the concept: I have a wireframe model and a surface that was used to generate the triangulations. 1) I make a plane perpendicular to each line at the start point. 2) I take the start point of every line and find the closest corresponding point on the surface. 3) I find the normal of the surface at that point and use the resulting vector to orient my original plane. 4) On that plane I create a rectangular section (16cm x 8cm), which should be oriented properly tangent to the surface. I can get everything to work except for the surface analysis. When I create a plane perpendicular to the resulting normal vectors, I expect to see a plane tangent to the surface. Instead they all appear to be perfectly horizontal. Therefore my alignments do not work properly and I cannot get the proper structural result (i.e., the deep part of the steel section should be seated perpendicular to the surface at my sample point. Can someone explain what I'm doing wrong? Thanks, Marc S.
