Imported surfaces
Imported surfaces must be promoted to the part environment before you can use them in parametric operations, or see the data in assemblies.
To analyze and promote surfaces to the part environment automatically upon import, select Auto Stitch and Promote on the Import Options dialog box (Construction Group Mapping must also be selected), or select Composite Feature Mapping as the import destination.
When Auto Stitch and Promote is turned on, Autodesk Inventor attempts to stitch surfaces into a quilt or solid. If the surfaces can be stitched into a single quilt or body, they are then promoted to the part environment. If surfaces cannot be stitched into a single quilt or solid body, they are left in the construction environment.
Workflows in construction environment
When Construction group mapping is chosen for import, and Auto Stitch and Promote is off, imported surfaces and wireframe are always placed in the construction environment.
In the part browser, double-click the Construction folder to enter the construction environment. In the construction environment, specialized commands help you analyze errors in imported surfaces and repair the data. You can stitch and unstitch surfaces, reverse the normal direction, extend a face, and break or trim intersecting faces.
Later, you can use Stitch and Copy Object commands in the construction environment to promote selected surfaces or solid bodies to the part environment. Even if the surface or solid has errors, you may still be able to use the data in some operations.