FBX file size issues

Issue

You want to know why the size of an FBX file exported from Revit® is larger than the original Revit RVT file.

Solution

The original Revit file does not contain the same data as the FBX file. Revit scene file information is based on Revit-specific construction information obtained from the Revit software and is more view-specific in nature. 

When this data is exported as an FBX file, it is converted to complex FBX scene information based on geometric data, such as vertex coordinates, UVs, and material data, which is embedded in the FBX file. This means FBX files must contain every Revit texture that is used for materials so that you can import the FBX file into 3ds Max. A Revit scene file does not need to contain any texture files because the textures reside in the Revit software, where the scene file can reference them.

The exported FBX file contains the actual geometric data in an uncompressed format, so it can be read in any software that supports the FBX file format.

The FBX file format will import all objects at the element level of a particular view. You can control the export data by adjusting the Visibility settings in your 3D view or camera view. Before you export an FBX file from Revit, you can optimize the view in the following ways:

1.  In the Visibility Graphic Overrides dialog box, clear the Visibility check box to turn off the unwanted categories and worksets:

2. Export only a part of your drawing or section detail by using a Section Box in your 3D view or camera view: 

3. When importing the FBX file into 3ds Max, follow these steps:
1. In 3ds Max, click Customize menu > Preferences.
2. On the Files tab of the Preferences dialog box, under File Handling, select the “Compress On Save” check box.
3. Save this file to your drive with a name such as BB.max. This will compress the file size.  

4. Click File menu > Reset and open the last saved 3ds Max file (i.e. BB.max) in your Final/Master project.