I have trouble interpreting how values in WorldCoordinateSystem will move&rotate objects in IFC when combined with IfcMapConversion. To visualise, I made a diagram showing the relations. Assuming my interpretation of WorldCoordinateSystem is correct, should RefLatitude/RefLongitude point to (A) or…

https://thinkmoult.com/ifc-coordinate-reference-systems-and-revit.html @Moult made a good explanation. There is some redundancy between having a mapping and also storing the Lat/Long mostly for backward compatibility.

in addition to the great explanations by @Moult , and to come back to your actual questions - the answer should be “C”. The RefLatitude and RefLongitute shall be used (as documented for IfcSite ) If asserted, the Longitude , Latitude and Elevation establish the point in WGS84 where the point 0.,0.,…

Also take a look at this post: [image] Coordinates of the IfcLocalPlacement/IfcCartesianPoint IFC do you know what is best practice on defining the coordinates of components in the IFC Structure, respectively the IfcLocalPlacement/IfcCartesianPoint? Depending whether the…

[image] TLiebich: 0.,0.,0. of the LocalPlacement of IfcSite Yes, and this is the reason for my post. “0.,0.,0. of the LocalPlacement of IfcSite”: Does this mean point B) or C) in the diagram where IfcSite (C ) is located at [196.0, 387.0, 0.0]? #8=IFCSITE('<guid>',#2,'Site',$,$,#34,$,$,.ELE…

good point, the sentence of “0.,0.,0. of the LocalPlacement of IfcSite” can indeed be misinterpreted. But what is meant is: 0., 0. ,0. (the origin) within the object coordination system of IfcSite, that is established by IfcLocalPlacement with an offest/rotation relative to the project coordinate s…

Dear gentlemen, The industry needs a proper guideline for this puzzle so everyone knows that the answer is “C”. The best would be to see this as an ISO Standard, but until this happens an official bsI guideline would do just fine. The reason is that we will see more and more issues concerning the c…

Thanks for the explanation @TLiebich ! I absolutely agree that it is confusing. I am sorry to say that I am not working with anyone on this currently. However, it is on my to-do list to build a little utility which will do things like: Report coordinates Replace coordinates Convert coordinates I…

Dion, there is one initiative from the dutch academic university that could be of interest. In civil design we have many challenges (on projects) for aligning ifc files to national grid or even project grids. Tools that make things easier have high demands! [image] tudelft3d/IfcLocator C…

Thanks Hans, It sounds interesting, especially when I see “Cesium”

Dion, When i use Blender i get this error messages. I tried 2.80 but it said “needs updating” This message i get when 2.78 is installed. I want to test your tools with some of my CAD models/geometry from Inventor and DWG. / step. Geometry made to IFC in various ways with various aspects like CRS / …

WorldCoordinateSystem, IfcMapConversion and IfcSite

Developers

ReD_CoDE October 19, 2019, 10:38am 4

Also take a look at this post:

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IfcSite does not reference the EPSG code for WGS84 and further inconsistencies with georef Developers	6	763	April 9, 2021
Coordinates of the IfcLocalPlacement/IfcCartesianPoint IFC	23	10202	October 2, 2019
How is the real world placement stored in a IFC file? Uncategorized	2	1328	October 18, 2023
Can WorldCoordinateSystem be removed? Developers	2	411	April 14, 2021
Offset stored in IFC file, how and where? Users	8	4014	July 15, 2020

WorldCoordinateSystem, IfcMapConversion and IfcSite

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