IFC handedness/coordinate system

Hi,

Does IFC always use the same coordinate system? I.e. y is up, z is forward.

Or does it depend on the modeling tool (Revit, Rhino, …) that makes the file?

If IFC always uses the same coordinate system, do modeling tools generally use the same one?

Extract from docs:

4.8.1 Product Placement

Product occurrences are placed in a right handed Cartesian coordinate system.

… and …

4.8.1.1 Product Local Placement

Product occurrences can be placed in 3D space relative to where they are contained. Placement is defined by a relative position (X, Y, Z coordinates), a horizontal reference direction, and a vertical axis direction. At the outermost level, relative directions are defined according to representation context; for example, +X may point east, +Y may point north, and +Z may point up.

The IfcAxis2Placement3D diagram further confirms this.

image

2 Likes