Although we cannot currently use two patterns at the moment, this is a trick to doing it when really needed. Simply combine the two patterns in the text file, creating a new pattern!
Notice, in the sample text file (Test.pat) below I copied the "Concrete" pattern from the Revit.Pat file (comes with Revit) and the "ANSI31" pattern from the Acad.Pat (comes with AutoCAD). I then created a new pattern by simply combining those two patterns to make a third option.
Here is the result in Revit for the sample pattern file and the three options...
- Revit's Revit.pat file is located here: C:\Program Files\Autodesk\Revit 2018\Data
- AutoCAD's Acad.pat file is located here: C:\Users\User\AppData\Roaming\Autodesk\AutoCAD 201?\R22.0\enu\Support
The Import Scale option can be used to create a new pattern without the need to edit the text file. For example, the Revit.pat file comes with a Block 8x8 pattern. If you need a 6.25" x 6.25" running bond tile pattern, just import the block pattern at the scale factor of 0.78125.
It would be nice if the Import Scale option offered and X and Y scale, rather than a just proportional. That would allow almost any tile size to be created quickly. Even better, a built-in feature to graphically edit and create fill patterns within Revit would be wonderful! I am not a big fan of editing text and xml files.