I tried placing the BridgeOverhead.obj from the library into the scenery that I'm working on, but I cannot change the height that it is placed using Set MSL. I also tried to make a post sink down into the ground with no success. Any help would be appreciated.

How do you position (height) of the Bridge light in WED?  I tried to enable MSL, but I'm not sure 1) how MSL works and 2) if I need it at all.  Thanks for the help!

MSL stands for Mean Sea Level, the altitude that the sea is, aka 0. When you are using it, X-Plane will put an object in that height you set, computed from sea level (0 ft), So if the airport is at 2,000 ft, and you want the object to be 10 ft above the ground, you must set 2,010 ft. Exact placement/height requires a lot of "trial and error".

3 hours ago, Airfighter said:

MSL stands for Mean Sea Level, the altitude that the sea is, aka 0. When you are using it, X-Plane will put an object in that height you set, computed from sea level (0 ft), So if the airport is at 2,000 ft, and you want the object to be 10 ft above the ground, you must set 2,010 ft. Exact placement/height requires a lot of "trial and error".

Thank you @Airfighter - I kind of thought that's the way MSL works, but when I tried it, I could never get it visible.  Maybe I was using feet instead of meters.  I wasn't sure what unit to use.  Thanks again for your assistance.

6 hours ago, SmokeDiddy said:

Thank you @Airfighter - I kind of thought that's the way MSL works, but when I tried it, I could never get it visible.  Maybe I was using feet instead of meters.  I wasn't sure what unit to use.  Thanks again for your assistance.

In WED go to View and you will find the selection feet or meters.

Not to mention it's also very difficult to get an exact MSL when users can use different meshes. What might fit snuggly on the ground in HD Mesh v3 might be floating or sunk in Ortho4XP, etc...