Revit Fill Patterns

In Autodesk Revit, Fill Patterns help define materials on an element's surface and when it is cut; in elevations, 3D views and sections. This post will cover a few thoughts related to this functionality within the software. Specifically, I want to talk about model versus drafting patterns, custom patterns and then a related and "accepted" Revit Idea.

Definition from the Revit.PAT file

• Model vs. Drafting patternsThere 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. Revit's existing restrictions limit the maximum size and density of the patterns, and a review of these restrictions is planned for a future release.

Fill patterns are used to represent materials on a surface. Any AutoCAD hatch pattern can be used by Revit. If you want an AutoCAD pattern to be used as a Model filled region (versus Drafting which changes scale with the View Scale) you have to add ;%TYPE=MODEL to the PAT file as shown below. The “;” symbol at the front rem’s out the line so even AutoCAD could still use the file… however it might be best to copy the ACAD.PAT file to another location specifically for Revit use.

Text used to define a model pattern

You may also see some patterns with ;%TYPE=DRAFTING as shown below, but Revit will assume “drafting: if nothing is specified.

Text used to define a drafting pattern

When creating a “model” pattern, if you try to use the AutoCAD ACAD.PAT file without making any changes, you will get this error.

Error when PAT file contains no model patterns

There are tons of hatch patterns for AutoCAD one can find via the web. If you need something custom you can either edit the PAT text file, or use a Revit add-in like Hatch22 or HatchKit to create it. Or Hatch Manager by GlobalCAD, which requires AutoCAD, but it makes the process very easy. You just draw the hatch pattern you want (see carpet squares example below) and then use this add-in to automatically generate the PAT file. This file can then be imported into Revit.

Update: Dmitry Chubrik, from the Russian BIM2B site, provided another option in the comments: Pattern Maker. Thanks Dmitry! If anyone knows of others, please share.

Custom pattern drawn in AutoCAD

Over in Revit Ideas, there is an idea about fill patterns that received a lot of votes (353 so far); Double patterns. This is a great idea which I voted for and added to the discussion. Even better, this post highlights the value of this mechanism to find out what we, as users, want. Notice Harlan Brumm, Revit Product Manager, replied, indicating this idea was under review. Later Sasha Crotty, Revit Core Product Manager, posted that the idea was accepted, meaning it will be added to the software in a future release (see image below)! I was even contacted by Autodesk to answer a few questions on this topic. Power to the people, go Autodesk!