{"id":457386,"date":"2023-09-04T17:11:20","date_gmt":"2023-09-04T15:11:20","guid":{"rendered":"https:\/\/bim-me-up.com\/?p=457386"},"modified":"2023-09-08T10:31:11","modified_gmt":"2023-09-08T08:31:11","slug":"revit-ifc-and-coordinate-systems","status":"publish","type":"post","link":"https:\/\/bim-me-up.com\/en\/revit-ifc-and-coordinate-systems\/","title":{"rendered":"Revit, IFC and coordinate systems"},"content":{"rendered":"

The most frequently asked question about Revit IFC definitely has to do with coordinates - so why is it so complicated? <\/p>\n\n\n\n

Both Revit and IFC have their own concept of coordinate systems and the handling of local and world coordinates, which will be briefly introduced in this article. <\/p>\n\n\n\n

Coordinate systems in Revit<\/h2>\n\n\n\n

Revit has 4 reference points, which are all superimposed in a new project in the standard template - we are talking about the internal Revit origin (Revit Internal), the project base point (Project Base Point), survey point (Survey Point) and the shared coordinates (Shared Site), whose origin is not visible, but is displayed as a reference in the project base point or survey point: <\/p>\n\n\n\n

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The points can be made visible in any view via Visibility \/ Graphics under Property (Site). <\/p>\n\n\n\n

There are different ways and possibilities to work with these points, so here are a few best practices from my point of view: <\/p>\n\n\n\n

Internal Revit origin<\/h2>\n\n\n\n

This point is fixed and cannot be moved. <\/p>\n\n\n\n

All model contents must be located within a radius of 16 km \/ 10 miles, otherwise the geometry of Revit can no longer be calculated and displayed correctly. This is not really a problem, as buildings of this size are not processed in a Revit file anyway. Problems only occur if content is linked that lies outside this radius (often happens with CAD files from the surveyor, for example). <\/p>\n\n\n\n

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Project base point<\/h2>\n\n\n\n

Defines the project coordinate system and is usually placed on a building ceiling or axis intersection. In principle, the point can be moved, but if possible it should be left at its original location, as this simplifies other workflows (e.g. IFC export). <\/p>\n\n\n\n

Survey point<\/h2>\n\n\n\n

Usually placed at a known point on the property, e.g. at the intersection of property lines, and often serves as the common coordination point for the surveyor. <\/p>\n\n\n\n

The survey point can also be moved, either in a fixed or unfixed state, as it also establishes a reference between the shared coordinate system. The bracket on the survey point symbolizes whether the survey point is currently fixed to the shared coordinate system or detached from it:<\/p>\n\n\n\n