When manufacturers are considering having content developed for the design community, some manufacturers may be well served by having pattern files created for their products. Pattern Files, or PAT files, are CAD files with a .pat extension. These files are used by CAD software and contain hatch patterns that provide information about pattern or texture. We sat down with Tyler Webster, Senior BIM Developer at CADdetails, to talk about PAT files, learn what they are, and what type of building and landscape product manufacturers can benefit from providing these to the design community.

The Use of PAT Files in AutoCAD and Revit

PAT files instruct AutoCAD and Revit how to draw the lines that make up the patterns, also referred to as hatch patterns.  AutoCAD and Revit have different compatibility issues since Revit hatch patterns can work in AutoCAD but AutoCAD hatch patterns may struggle to work in Revit.

Revit includes two PAT file types: model pattern files and drafting pattern files.  Drafting patterns change with scale, whereas model patterns keep proportions when changing scales.  Model patterns remain a fixed size relative to the model, and drafting patterns remain a fixed size relative to the sheet.
PAT files are written in text format and can be edited with a standard text editor. Plug-ins such as pyRevit provide a more user-friendly interface for creating and using PAT files.

What Types of Products and Systems Work Best for PAT Files

PAT files are ideal for showcasing different pattern layouts. Examples of systems that benefit from different pattern layouts include stone, brick, stucco, wall patterns, tile systems, and various roofing including shingles. Using PAT files allows for consistent standards for representing standards.

What Limitations Exist for the Application of PAT Files?

There are a few limitations to the textures and patterns that can be depicted with PAT files, but the files themselves are 2D black and white representations of patterns. Thus for organic patterns such as the surface of water, rendering software does a better job of illustrating the texture of objects.

What Should Building Product Manufacturers Know About PAT Files?

Stone and tile manufacturers particularly should consider having PAT files developed. These files would be helpful to designers using these products in their projects. Designers benefit from these files by being able to have textures and patterns line up properly in their designs. Regardless of which view is shown, textures and patterns line up allowing architects to specify a fairly accurate representation of the pattern of a system based on the manufacturer's supplied images.

What Information Can Designers Obtain from Using PAT Files?

There are some patterns that make calculating the amount of required materials difficult. For example, there is no way to automatically calculate a chevron pattern for an entire floor. By employing a PAT file, visual calculations can be made to determine the amount of flooring materials required. Proper pattern files for your system allow for fairly precise calculations.

What Are Other Benefits of PAT Files for Designers?

PAT files allow a design team to adjust the scale of a pattern.  Scale can be adjusted to match textures in JPG image files.  While it may seem desirable to work with realistic textures, PAT files use much less resources to illustrate a pattern than a rendered texture requires.  Working on large models with textures can slow a designer’s computer.

PAT files also provide a line representation of what the pattern should be.  This is useful for showing patterns in 2D CAD.  Working drawings and blueprints are not printing full color texture but they may still need to indicate patterns. There are trade-offs to this as texture provides depth that patterns cannot. 
Are you a building or landscape product manufacturer that may benefit from having hatch patterns or PAT files available for the design community?  If you would like to learn more about how to have these files created for your products and shared with architects, engineers, and designers, reach out to us at CADdetails through our BIM information page for manufacturers.

Author: Elinor Hutcherson