Converting ACAD Hatch Patterns into Revit Hatch Patterns

If you want to create hatch patterns from scratch you need to read the revit.pat file, this is a txt file that will walk you through the process. Search for this file under the Revit Architecture program file.

The only real difference between a Revit hatch and a ACAD hatch is a small piece of script that is added to the pat script.

Revit reads hatch patterns a little differently than Autocad. If you add the script as outlined in the above mentioned file (you can copy clip it in) to a copy of your ACAD hatch patterns you can then import the pat filers into Revit.

you will need to add a line or two to AutoCAD patterns to get Revit to recognize them.
add
%TYPE=MODEL
the line after the pattern description if you want to use it as a model pattern. add
%TYPE=DRAFTING
the line after the pattern description if you want to use it when something is cut.

This file contains the standard set of custom fill patterns distributed with Autodesk Revit. Since it is part of the standard installation, do not change it. Any changes you make may be lost when you update Revit. To define custom patterns, create a new file using this file as a template. Fill patterns are also known as hatches and fills.

Model vs. Drafting patterns

There are two types of fill patterns in Revit: model and drafting. Model patterns are used to depict real-world elements, such as bricks, shingles, tiles, etc. They are defined and display in model units. An 8x16 inch brick pattern will show exactly 12 courses on an 8-foot-tall wall. A 2-meter-tall wall with a 200x400 mm brick pattern will have 10 courses. Model patterns appear denser at coarser view scales and sparser at finer ones.

Drafting patterns are defined in paper units. If you import the pattern at scale 1 and print at 100% zoom, the pattern's dimensions on paper will be exactly as specified in the file, regardless of view scale. Drafting patterns are used to symbolically denote materials such as  steel, concrete, sand, etc.

Drafting patterns are typically defined with smaller numbers than model patterns. Drafting patterns usually contain sizes from 0.04 to 1 inch (1 - 25 mm); model patterns usually contain sizes from 2 to 20 inches (50 - 500 mm). These are guidelines only, not enforced by Revit.