End Effector Notes: STL, VRML, and Colors
I’ve been having major problems importing my end effector into Denso WINCAPS III and maintaining my desired colors.
WINCAPS III can only import Direct-3D (*.X) or VRML Ver 2 (*.WRL) files.Â On the other hand, most MCAD software won’t export VRML files.
I used DesignSpark Mechanical (DSM) to create my design.Â DSM can export 5 3-D file formats: STL, OBJ, 3D PDF, SKP (Sketchup), and XAML.Â Â I was frustrated trying to set the colors I wanted in DSM; help (including blogs and forums) is still very limited, and I couldn’t figure out how to change the color of imported STEP files.Â I was able to get to this:
Since I choose to export to STL, the next step was to convert from STL to VRML using meshconv, but when I imported the resulting VRML file into WINCAPS III I got this:
Yuck!Â All my color is gone, and my part is white hot and glowing purple.Â I’m pretty sure part of the problem is that the WINCAPS simulator has a bright light, which as far as I can tell can’t be adjusted; when the part is rotated, the bright spots change.Â But the major problem, which took me a while to figure out, is that STL files normally do not retain any color information.Â After all, it’s not needed by most 3D printers, and STL was invented for 3D printers.
I did a little more research on the DSM export formats.Â I am using two conversion tools, meshconv (a command line converter) and MeshLab (which includes a viewer and much more).Â Of the 5 DSM 3D export formats, meshconv and MeshLab are only able to import STL and OBJ.Â While OBJ may be able to contain color information, it wasn’t retained when I tested exporting from DSM to OBJ and then importing in meshconv or MeshLab.
I tried using SketchUp.Â I was able to color the parts with a bit of effort (see below for an example), and export to VRML using a add-on, but WINCAPS III didn’t like the resulting VRML file.
So I ended up using MeshLab: I exported from DSM to a STL file, imported the STL file into MeshLab, colored using MeshLab (pretty easy), exported from MeshLab to VRML, and finally imported the VRML file into WINCAPS III.Â The colors in WINCAPS are pretty different from MeshLab’s colors, but they’re much better than my first attempt.