If you are not using Behavioral Modeling, then create a Parameter that is assigned the value of the Evaluate Feature.

Write it so (the names used below are for example only)

1.Create an Evaluate Feature and name it SURFACE (example only: this is the feature name).
2.Enter the name of the dimension as AREA (example only: this is the measurement name).
3.Create the Evalaute Feature.
4.In the Model Tree, the feature item SURFACE will appear.
5.Create a relation that calls the evaluate feature value to a parameter (create one called TOTAL_SURFACE).
TOTAL_SURFACE = area:fid_surface

In the Model Tree, the evaluate feature is shown as below:

<measurement_name>:<FID_featurename>

Now simply add the part or assembly parameter to your Model Tree columns.

Good luck.

http://www.3dlogix.xom

Thanks for the info!
Your explanation was clear and very accurate.
I first got the idea from a printed article. The problem was though, the author made a lot of assumptions. This is the first time that I have wanted (or needed) to drive a parameter off of a relation.

Thanks again,

JW

Tactex Controls Inc.

Glad I could help.

http://www.3dlogix.com