The new ACS Plane Snap has replaced the Depth Lock which was used in 3D files to keep elements placed as planar. In V8i the new way of placing elements as planar is to use the ACS Plane Snap lock. The Auxiliary Coordinates dialog has moved to the Primary toolbar for easy access the whole process can be done in 3 easy steps.

1. From the Primary Toolbar open the Auxiliary Coordinates dialog.
   
2. In the View 1 row under the Origin Z column type your active depth in the field.
   
3. In the Snap Lock flyout or dialog check ON ACS Plane Snap.
   
   Now when you place elements in the 3D file even when you are snapping to varying elevations the element will be planar at the desired elevation.

Additional Notes

• The Key-in AZ= could still be used to define the active depth of the view.
• Remember the active depth can’t be set outside the view clipping plane.