Brian Fitzpatrick

It's been explained to me that 2.5D refers to a terrain that has z data for the ground elevations but won't allow you to go to a higher Z to represent items above ground.

The breaklines are in a cell, if you drop it you should be able to add the breaklines to your terrain.

I noticed that the file was saved with OpenRoads Designer 10.07.01.32, this version has some defects and I'd recommend to install the last one, 10.07…

A terrain Model (I used the word element above - as it is a MicroStation element) is not equal to a STM. They are different element types - you cannot add breaklines to a STM.