Q: How do I get AutoCAD solid models into Photopia?

A: Solids within AutoCAD can quickly be converted into Polyline Mesh surfaces (which Photopia accepts) by following these steps:

1. Put each part onto a unique layer. This will facilitate assigning materials in Photopia since materials are assigned to each layer in the model.
2. Set the mesh resolution with the FACETRES system variable. The default value of 0.5 is very low and results in a course polygon mesh approximating the shape of your model. We recommend you set the value to a higher level to create a more accurate part shape. If you are using Photopia 1.5, then a value between 5 and 8 is recommended. If you are using Photopia 2.0, then use the maximum setting of 10.
3. Export the solids to a 3D Studio files using the 3DSOUT command or by selecting File / Export from main menu and setting 3D Studio as the file type. If you have AutoCAD 2007 or later, please follow these directions to enable the 3DSOUT command. Keep the default settings on the 3D Studio File Export Options screen. Note: If the mesh contains too many vertices, then AutoCAD will not export the part. The 3DSOUT command will give an error message if this occurs. If you encounter this problem, then try one of the following options:

   a. Reduce the FACETRES variable to a lower value and try again. If the 3DSOUT command continues to fail or if the facet resolution is not acceptable at the level AutoCAD will support, then try the next option.

   b. Use the EXPLODE command on the solid to convert it to a set of regions and/or bodies. Then create several new layers and put a portion of the regions and bodies onto each of the new layers. Now try and export the set of regions and bodies from each layer individually using the 3DSOUT command. If it still fails, then reduce the amount of geometry on each layer until it succeeds.

4. Import the 3D Studio file into a new AutoCAD drawing using the 3DSIN command or by selecting Insert / 3D Studio from the main menu. Click the Add All button in the Available Objects section of the Import 3D Studio File Options screen and keep the rest of the settings at their default values.
5. Save the meshed parts to a 2000 DWG file. This .DWG file can then be imported into Photopia.