View Full Version : I wish for negative dimensions so I can offset a secondary extrusion in any direction relative to the primary extrusion.

2011-10-10, 05:27 PM
Summary: I wish to be able to create negative dimension values in the family editor.

Description: I create a lot of MEP families which often have connectors attached to small extrusions. Typically the connector is centered on a face of the larger extruion that is the body of the object, but sometimes it will need to be moved to the left or to the right, or upwards or downwards, on an instance basis. Offsetting to the right or upwards (in the postive direction) is no problem, but there is no way to move the extrusion to the left or down (in the negative direction) relative to a reference plane that is stationary, if the default location of the connector is at the center of the body of the object.

Product & Feature: Revit MEP

Submitted: Mon, 10 Oct 2011

2011-10-10, 05:52 PM
A work around I have used is that I lock a reference plane to the left of the center plane, usually 4 feet. I then lock the element that need move to the left to a separate plane. Next use a instance parameter to control the distance from the Left plane to the element plane. The center default would be 4 feet, 0 would be 4 feet to the left and 8 would be 4 feet to the right.

2011-10-10, 06:03 PM
Thanks for the idea. I did consider doing this but the family in question has several types of varying sizes, so keeping the center alignment as a default for all sizes is important. I suppose I could construct some parameters with conditional statements to control the placement of the smaller extrusion, but I'd really rather just type "-3" into my Offset from Center parameter and have Revit do the rest. That's my wish!