Legacy Intersection Mode for Older-Version Projects

If you open an older-version project in ArchiCAD 17, the Legacy Mode for element intersections will be turned on by default to maintain the appearance of your model!

In Legacy Mode, the automatic and Building Material priority-based intersections implemented as of ArchiCAD 17 will not take effect in 3D. Connection methods used in ArchiCAD 16 and earlier versions will be used. You may prefer this when working on an older project, to ensure that your existing intersections remain intact.

Legacy Mode is controlled in Options > Project Preferences > Construction Elements.

If Legacy Mode is on, your model element intersections will work as they did in ArchiCAD 16 and before. Note that the Building Material attribute is used in Legacy Mode as well – but the priority-based connections will not take effect in 3D (except for Walls, where they will work as in ArchiCAD 16 and earlier versions). Also, in Legacy Mode, the Surfaces assigned to Building Materials are not displayed. Only element-level surfaces can be shown.

For specifics on how this checkbox affects intersections of the different construction elements in Legacy Mode, click the Info button in the dialog box.

When turning legacy mode OFF, modeled connections that do not involve collision will not clean up automatically. However, any newly placed elements whose collisions are modeled using the new modeling methods described above will clean up as expected for ArchiCAD 17. This way, even when you migrate an older-version project, you will be able to enjoy the benefits of the new intersections features, while maintaining the existing model as it was.