Every CAD conversion is different and depends on the user's requirements for the geometry and how accurate the materials need to look.
1. Remove spaces from the names of files.
2. Create just one material, UV map, and texture per model.
3. If your model does not require articulating parts, all geometry can be collapsed into one layer providing the polygon count doesn't exceed 100,000.
4. If the model does not require textures, then only one material is needed.
The attached tutorial covers converting CAD models for use in STK via a free 3D modeling program called Blender.
Sample files are included.
The tutorial includes:
1. Preparing the CAD file for export
2. Setup of Blender interface and plug-ins for importing .STL files
3. Importing the .STL files
4. Scaling objects
5. Object Parenting
6. Smooth Shading
7. Assigning Materials
8. Solar Panel Groups
9. Assigning UV maps
10. Assigning Textures
11. Sensor or Effect attach points
12. Axis alignment
13. Articulation Setup
14. Exporting to .DAE (Collada)
15. Ancillary file creation
16. Notes on Modeler
17. Texture paths in Collada files
18. Current Collada Limitations
19. STK Implementation
The file can also be obtained via this DropBox link:
If you feel that you need any clarification about this tutorial or if you simple have additional questions, please don't hesitate to ask.