Export the Bounding Box Only
In some cases, you may want to use different geometry for certain scene objects in 3ds Max than you do in Unreal Engine. For example, you may want to replace highly complex or very dense geometry that you use in offline rendering in 3ds Max with lighter versions that perform more efficiently in realtime.
In these cases, you still need these objects to be included in your scene, so that you can replace the objects in the Unreal Editor at their correct locations. However, translating the full geometry of complex objects makes the export and import process take longer. It also leaves you with large, unnecessary Static Mesh Assets in your Project content.
You can get the best of both worlds by using the Datasmith Attributes modifier to mark certain objects for special handling during the export process. Instead of exporting the full geometry, you can have Datasmith create a new, lightweight geometric representation of the object based on the object's 3D bounding box. The objects are still included in the Datasmith scene, with their original names, at their original locations, but with their geometry aggressively reduced to a simple bounding volume.
- Select the object or objects in your scene that you want to replace in the Unreal Engine physics simulation with a different object, and apply the Datasmith Attributes modifier. See Applying the Datasmith Attributes Modifier.
- Under the Export Geometry As section of the Datasmith Attributes modifier settings, select Bounding Geometry.
After you use Datasmith to import your scene into Unreal Editor, you should see that the scene objects you marked with the Datasmith Attributes modifier don't show up in your Level with their original geometry. Their geometry is replaced by simple grey bounding volumes.
For example, in the image below, the lift objects in the center of the 3ds Max scene have been marked for export as bounding boxes only. In the Unreal Engine Level after import, they appear only as simplified volumes with default Materials.