For pieces to be accessed as separate, editable pieces in Element, they need to have separate materials mapped to the polygons. In most 3d applications you can drag a new material to the pieces you need to be separate in Element.
Giving each object it's own material in the full 3d app then importing to Element as an .obj or C4D file, allows them to be adjusted and separated in Element. You can turn off pieces with the blue buttons next to each material.
Importing Objects and Building Materials
Exporting 3D objects for Element 3D
Exporting from Blender & 3D Max (and other software)
Tips for working with C4D files in Element
Objects need to be exported as an .obj file
Element auto-triangulates models that aren’t already triangulated. Performance will be increased with the model Pre-Triangulated.
Make sure that all polygon normals are facing the correct way. If the Polygon Normals are backwards they will appear as invisible.
Make sure that the UVW Coordinate information is being saved out with your obj. This is usually a checkbox in the export settings. This is the information telling the program how to map materials.
Make sure that the smoothing groups information is being saved out with your obj. This is usually a checkbox in the export settings. Without this, the model might look blocky.
Auto Normals & Edge Threshold
If your program can’t export the
smoothing groups correctly, you
might want to try using Auto
Normals and Edge Threshold to
try to get a smoother look.
See 3D Object Troubleshooting if
your model is not looking correct.