Import FBX Revit models into 3ds max

Importing FBX Revit models into 3ds max

Although Autodesk advertises with the interoperability of their specific products, in practice, exchanging files between one app and another can be a cumbersome and painstaking task.

It can take days of work to discover certain workarounds for problems that Autodesk really never solved (and should solve). One of those problems is the import of Revit FBX models in to 3ds max.

And in general there are just a few minor details you have to take in account. But if nobody tells you, and you have to figure it out yourself it can become a real headache! Here are the pointers:

Unit size

First thing you have to do when importing fbx models into 3ds Max is to make sure that your system units of your scene (under customize > unit setup) are set to feet! Although you can indicate the system units in Revit, for example metric unit size, apparently Revit's system units internally still work with feet (damn Americans). This is also indicated by Autodesk in this post in the "Area".

If you do not import your FBX model into a file setup in feet, you will notice that you will have problems applying UVW maps to objects coming from Revit. The scaling of the uwv map will not be correct and you will have to recalculate the scaling from feet to your unit size for every uvw map you apply.   

If you have set up the file in feet and you still prefer to work with the metric system, no problem, then just set your viewing display to mm or meters. If you have other files (xref’s) setup in another unit size then you can easily xref the file setup in feet into a file setup in another unit size and it will scale correctly.

FBX file linking

The best way to connect or import Revit FBX models is by linking the fbx file with 3ds max through the file link manager. Although the file link manager has a few options, the following details need attention.

Firstly setup a preset. In the preset specify the following items:

Combine entities:

You can choose to combine entities by material, by category, by familie type, as one object or do not combine. If you have followed the pointers for exporting fbx models from Revit then, if correct, you will already have separate files with building elements. We will choose the option combine by category. This option will combine geometry based on building elements (for example, doors, windows, mullions, floors, etc.).

Although the help in 3ds max indicates that Revit categories will be imported as a separate layer, this is not true.  They will be imported as separate objects within one layer! The layer will be named after the fbx file name that you have linked. Therefore it is useful to break up the fbx model in to chunks (read more here) and give them corresponding names because your layers in 3ds max will be named after the file that you link. So now your layers will be organized according to the building elements chunks that have been exported from Revit. 

Objetcs:

• Uncheck lights, daylights and cameras because we will be placing these in 3ds max

Materials:

• Check  use scene material definitions as we will be applying the materials in 3ds max.
• Check use scene material assignments on reload so if we reload the linked model it will keep the materials that we have applied in 3ds max.

Now you are ready to select a fbx file and attach it with your setup preset.

If you like to make changes to your mesh you can drop an edit poly modifier on top of it. You can always choose to merge your fbx model into your scene, but by doing so you will not be able to update your model.