Project Base Point elevation conversion to number gives different value

In one building I noticed that Elevation output from the Level Identity component is different by 10 mm when converted to numbers. I can’t share a piece of the Revit file now, but a screenshot may be enough to communicate this problem.

I’m using RiR 1.9.8326 and Revit 2022.1

That’s odd. Not seeing it here, but i’m currently in the daily release. I’ll see if i can replicate.

Is the building far from origin or have any shared coordinates being used?

Yes, shared coordinates are in use. Among multiple buildings, there is one that causes trouble.

In one building survey and base points look like this.

Where in other files looks like this:

Hi @Czaja.

This is because your ‘Project Base Point’ is at 10 mm. from the world coordinate system or ‘Internal Origin’ in Revit.

Keep in mind that Grasshopper works in World coordinate system so any value is converted back when used in Grasshopper.

If you change your Level Style to report Elevations from ‘Survey Point’ conversion to string will reflect this and will say

  • ‘Survey Point’ + 10
  • ‘Survey Point’ + 4010
  • ‘Survey Point’ + 510

In this case.

But no matter how the style is formatting the Elevation, Grasshopper needs a stable coordinate system and it uses the world coordinate system called ‘Internal Origin’.

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