Project Preferences - Reference Level

[Anonymous]

I'm having trouble understanding how to setup a terrain using a Reference Level (AHD).

The attached survey shows the FFL of the building will be at RL 38.29, and the lowest spot level on the SS is at RL 36.58

In the Project Preferences/Reference Levels, what do I need to set my AHD Elevation to, -36000? being roughly 500 below my lowest RL??

[David Shorter]

Yes consistency is the critical issue. Currently there also seems to be and issue with exporting to IFC
Getting this checked out as we speak.

[David Shorter]

If you are collaborating with consultants via IFC do not use reference levels or altitude in your project as these levels are not passed though to the IFC file. When working with IFC you must use real levels

[Anonymous]

Same here.

When coordinating with IFC or any other format I find it very important, if not mandatory to set the project origin to match an agreed common origin for all files. I have worked on some projects where this was not the case and it is a big (and risky) pain in the butt.

[Anonymous]

Thanks Barry Kelly this worked for me.

[KeesW]

I am drawing a large site for proposed apartments and am having trouble using levels in a useful way. We have surveyor's DXF and DWG drawings indicating that site levels range from about 166 to 172m above the the AHD (Australian height datum). Following David Shorter's advise, I've set my story levels with AHD=0 on the bottom and the buildings will then be located about 162m above this. My mesh 3D shows a very long vertical tube under the site (just as well we aren't building om Mt Everest!) which is ungainly. I know that we can control this in elevations and sections by selecting the appropriate vertical extensions for the views, but how does one control it for the 3D views?

[Barry Kelly]

Try setting a negative height to your mesh height (skirt).
Oddly a positive height will lower the base of the mesh below the base level.
So try say -161m to raise the bottom of the mesh.

Barry.