AutoCAD Hatch Pattern Generator: About 1,000 Patterns as .pat Files

⬇ Open Hatchy and get a .pat file

Hatchy is the largest library of parametric hatch patterns: ~1000 patterns, each with adjustable sizes. It turns a pattern into a hatch pattern (.pat) file. Pick a pattern (herringbone, running bond, stack bond, basketweave, chevron, fish scale, cobblestone and more), set its sizes, rotation and joints, check the preview and download the file. The Software select picks the file: AutoCAD (.pat), Revit model or Revit drafting. This guide has a section for each program, with its own way to load the file: AutoCAD, Rhino, ZWCAD, Inventor, SketchUp, Revit model pattern and Revit drafting pattern. The preview draws the same lines the file contains. One .pat download per UTC day needs no licence; further downloads need Hatchy Pro, a lifetime licence, and a 3dshouse account is asked for at the first download (see Availability and terms below).

What a hatch pattern file is

A hatch pattern is stored in a .pat file: plain text where every line after the name describes one family of parallel lines. Autodesk gives the line format as angle, x-origin, y-origin, delta-x, delta-y, dash-1, dash-2, …: the angle of the line, the point the first line passes through, the displacement between family members along the line (used only for dashed lines), the spacing between family members measured perpendicular to the lines, and the dash lengths. The file starts with a header line that begins with an asterisk and holds the pattern name.

A layout of straight, repeating tiles gives a short file. A pattern with curves gives more lines, because each curve is drawn as a run of straight chords (see Arc segments below).

What Hatchy does

• ~1000 patterns. The all-patterns page has a search box and Layout and Shape filters, and every pattern opens in the editor, for example herringbone or running bond.
• The pattern’s own parameters (tile sizes and the like) and a Rotation field that turns the whole hatch.
• Units: mm or in. The switch at the top sets the unit of the numbers you type and of the numbers written in the file.
• Horizontal joint and Vertical joint for tile layouts, and Arc segments for patterns with curves, explained below.
• A preview that is the file. What you see is drawn from the lines the .pat contains, so it shows the lines the file describes.
• Software select and Download .pat. Pick the file, then press the button. The file is named after the pattern, for example herringbone.pat for AutoCAD.
• The same pattern as a texture. For a pattern made of tiles, a link in the editor opens it in Texturic, at 3dshouse.com/textures/, as a seamless texture.

How to make a hatch pattern file

1. Open Hatchy and pick a pattern.
2. Set the pattern’s sizes and the Rotation.
3. Pick mm or in to match your drawing.
4. For a tile layout set Horizontal joint and Vertical joint; for a pattern with curves set Arc segments.
5. Pick the file in the Software select: AutoCAD (.pat), Revit model or Revit drafting. Each program section below says which entry it uses.
6. Look at the preview: it is the file.
7. Press Download .pat. At your first download Hatchy asks you to sign in with a 3dshouse account; the first download of each UTC day needs no licence.

Joints: one line or two

Tile layouts have two rows: Horizontal joint, the gap between rows, and Vertical joint, the gap between the tiles of a row. A joint of 0 draws one line along each joint, the plain outline of the tiles; a joint shared by two tiles is one line, not two. Above 0 Hatchy draws both edges of the joint, so every tile is drawn smaller by half the width on each side and the gap between neighbours is the width you typed. Tile layouts start at 5 mm; use 0 for a light hatch, and a width above 0 when you want the joints to read as gaps in the drawing. Patterns made only of lines or open motifs have no joints and the section is not shown. The header line of the file records the joint widths that were drawn.

Curved edges and Arc segments

A .pat file is built from straight lines that repeat, so a curve, such as the arcs of a fish scale, is drawn as straight chords. Arc segments is shown for a pattern that has an arc, and its hint in the editor says it plainly: the number of straight segments in a full circle, as SketchUp’s 24, with 0 as smooth as possible. More segments follow the curve more closely and make the file larger.

A .pat can only repeat along fixed line directions, so each chord of a curve is snapped onto one of the directions the pattern repeats along; that is why the hatch repeats with no gaps. The snap moves the end of a chord by a small distance, and a shorter chord moves less. More Arc segments therefore means shorter chords, a smaller move and a larger file. A pattern whose edges are all parallel to its repeat directions, such as stack bond, has nothing to snap and is written exactly.

Units and scale

AutoCAD reads the numbers of a .pat file as drawing units: Autodesk’s own example measures its ANSI31 hatch in “0.125 drawing units”. So pick the unit your drawing uses before you download. The numbers in the file are in the unit you picked, and the first line of the file records it as a comment (AutoCAD ignores text after a semicolon). In AutoCAD the hatch can still be expanded or contracted with Scale, which Autodesk describes as available for a Predefined or Custom pattern, and turned with Angle.

Install the .pat file in AutoCAD

Pick AutoCAD (.pat) in the Software select; it is the file AutoCAD reads.

1. Keep the file name Hatchy gave it. Autodesk: “Each custom hatch pattern is stored in a separate PAT file that has the same name as the custom hatch pattern”, so the pattern “WATER” goes in water.pat.
2. Put the file in a folder listed in AutoCAD’s Support File Search Path (add the folder to that setting if it is not there yet).
3. Run HATCH. If the ribbon opens instead of the Hatch and Gradient dialog, set the system variable HPDLGMODE to 1: Autodesk says that if you prefer the dialog, you set it to 1.
4. In the dialog set Type to Custom. The Custom Pattern list shows the custom patterns, the most recently used at the top. Pick the pattern.
5. Pick the area to fill, and use Angle and Scale to adjust the hatch.

If you would rather not keep separate files, Autodesk also allows adding the pattern to the User Defined Hatch Patterns section of the standard acad.pat or acadiso.pat.

If AutoCAD does not list the pattern

Autodesk’s own checklist for a custom PAT file that does not work: the pattern name is 31 characters or fewer, there is a blank line after the last definition (otherwise the last pattern is not accessible), the file is in a folder of the Support File Search Path, and the file is named after the pattern. Each line of a pattern definition can hold up to 80 characters. Hatchy files follow the first two and the last; if the pattern is missing, check the folder first.

Rhino: load the .pat file

Rhino reads the same .pat file as AutoCAD, so pick AutoCAD (.pat) in the Software select; McNeel’s wiki says Rhino uses the same format as AutoCAD.

1. Download the file with AutoCAD (.pat) selected.
2. In Rhino open Options, then Document Properties, then Hatch.
3. Press Load and pick the .pat file.

ZWCAD: load the .pat file

ZWCAD reads the same .pat file as the AutoCAD entry, so pick AutoCAD (.pat) in the Software select.

1. Download the file with AutoCAD (.pat) selected and keep it in a folder of its own or a folder you already use for support files.
2. In ZWCAD open OPTIONS, then File, then Support File Search Path, and add that folder.
3. Run HATCH and pick the pattern in the hatch pattern list, as ZWSOFT’s user guide describes.

Inventor: load the .pat file

Inventor reads the same .pat file as the AutoCAD entry, so pick AutoCAD (.pat) in the Software select.

1. Download the file with AutoCAD (.pat) selected.
2. In the hatch dialog open the Pattern list, choose Other, then Load, and pick the file.
3. Set the loaded pattern to Offered, as Autodesk’s Inventor help describes.

SketchUp: import the .pat file

SketchUp reads the same .pat file as the AutoCAD entry, so pick AutoCAD (.pat) in the Software select; SketchUp’s help describes one pattern per .pat file, which is what Hatchy writes.

1. Download the file with AutoCAD (.pat) selected.
2. In SketchUp open Window, then Default Tray, then Hatch Patterns.
3. Press the + button and pick the .pat file.

Revit model pattern: import the .pat file

Revit has its own model file, so pick Revit model in the Software select; it is a .pat file like the others, made for Revit’s model patterns.

1. Download the file with Revit model selected.
2. In Revit open Manage, then Additional Settings, then Fill Patterns, choose New, pick Custom and browse to the file.
3. When Revit asks whether the pattern is Drafting or Model, choose Model.

Autodesk describes a model pattern as one that scales with the view: it keeps its size on the model, so it grows and shrinks on screen with the view scale. Use it when the pattern should keep its real size on the building.

Revit drafting pattern: import the .pat file

Revit has its own drafting file, so pick Revit drafting in the Software select; it is a .pat file like the others, made for Revit’s drafting patterns.

1. Download the file with Revit drafting selected.
2. In Revit open Manage, then Additional Settings, then Fill Patterns, choose New, pick Custom and browse to the file.
3. When Revit asks whether the pattern is Drafting or Model, choose Drafting.

Autodesk describes a drafting pattern as one that keeps its size on the sheet whatever the view scale. Use it when the pattern should look the same at every scale.

Limits

• Long names are cut. A pattern name is limited to 31 characters, so a longer pattern name is cut to 31 characters, in the file name too.
• Very dense hatches. Autodesk notes that AutoCAD may reject a very dense pattern, with a message about hatch scale or dash length, and gives the HPMAXLINES system variable (0 to 10,000,000) as the limit to change in AutoCAD 2008-based products and later. More Arc segments make a denser file.
• Straight lines only. Curved edges are straight chords, as explained above.

Availability and terms

Hatchy includes one .pat download per UTC day, whichever software you picked; the count resets at 00:00 UTC. Further downloads that day need Hatchy Pro, a lifetime licence. A 3dshouse account is asked for at the first download: a sign-in card appears when you press Download .pat, and the download then goes ahead. Opening the editor, browsing patterns, changing settings, rotating, switching units and looking at the preview are never counted. These are the terms in force when this page was last updated and they may change.

The same pattern as a texture

Patterns made of tiles are also Texturic patterns, so the pattern you hatch in a CAD program can become a seamless texture with PBR maps for a render or a SketchUp material. Open it at 3dshouse.com/textures/<pattern>/, for example herringbone, or read about Texturic. Patterns made only of hatch lines exist in Hatchy only.

FAQ

What is a hatch pattern (.pat) file?
A plain text file that tells a CAD program how to draw a hatch: each line of the file describes one family of parallel lines by its angle, origin, spacing and dashes. Hatchy writes that file from a pattern such as herringbone, running bond or fish scale.

Which software does Hatchy make a file for?
The Software select next to Download .pat has three entries: AutoCAD (.pat), Revit model and Revit drafting. Each program has its own section and FAQ answer with its own load route: AutoCAD, Rhino, ZWCAD, Inventor, SketchUp, Revit model pattern and Revit drafting pattern. The button stays Download .pat whichever entry you pick.

How do I use a .pat file in Rhino?
Rhino reads the same .pat file as AutoCAD, so download it with AutoCAD (.pat) selected. In Rhino open Options, Document Properties, Hatch, press Load and pick the file. McNeel’s wiki says Rhino uses the same format as AutoCAD.

How do I use a .pat file in ZWCAD?
ZWCAD reads the same .pat file as the AutoCAD entry, so download it with AutoCAD (.pat) selected. Add its folder under OPTIONS, File, Support File Search Path, then run HATCH and pick the pattern in the hatch pattern list, as ZWSOFT’s user guide describes.

How do I use a .pat file in Inventor?
Inventor reads the same .pat file as the AutoCAD entry, so download it with AutoCAD (.pat) selected. In the hatch dialog open the Pattern list, choose Other, then Load, pick the file and set the pattern to Offered, as Autodesk’s Inventor help describes.

How do I use a .pat file in SketchUp?
SketchUp reads the same .pat file as the AutoCAD entry, so download it with AutoCAD (.pat) selected. In SketchUp open Window, Default Tray, Hatch Patterns, press the + button and pick the file. SketchUp’s help describes one pattern per .pat file, which is what Hatchy writes.

How do I use a Revit model pattern?
Download with Revit model selected, which is the file made for Revit’s model patterns. In Revit open Manage, Additional Settings, Fill Patterns, choose New, pick Custom and browse to the file; when Revit asks Drafting or Model, choose Model. A model pattern scales with the view.

How do I use a Revit drafting pattern?
Download with Revit drafting selected, which is the file made for Revit’s drafting patterns. In Revit open Manage, Additional Settings, Fill Patterns, choose New, pick Custom and browse to the file; when Revit asks Drafting or Model, choose Drafting. A drafting pattern keeps its size whatever the view scale.

How do I use a .pat file in AutoCAD?
Save the file in a folder listed in AutoCAD’s Support File Search Path, keeping the file name Hatchy gave it. Then run HATCH, open the Hatch and Gradient dialog (set HPDLGMODE to 1 if the ribbon opens instead), set Type to Custom and pick the pattern in the Custom Pattern list.

Why must the .pat file name match the pattern name?
Autodesk’s rule: each custom hatch pattern is stored in a separate PAT file that has the same name as the custom hatch pattern, so the pattern “WATER” must be in water.pat. Hatchy names the file after the pattern for that reason, so do not rename it.

Why does my hatch not show up in AutoCAD?
Autodesk lists four checks: the pattern name is 31 characters or fewer, the file ends with a blank line after the last definition, the file is in a folder of the Support File Search Path, and the file is named after the pattern. Hatchy files meet the first two; check the folder and the file name.

What do Horizontal joint and Vertical joint do?
They set the gap between the tiles of a tile layout, between rows and between the tiles of a row. At 0 the hatch has one line along each joint. Above 0 it has both edges of the joint, with the width you typed between them. Patterns made only of lines or open motifs have no joints, so the section is not shown for them.

What is Arc segments?
A .pat file is made of straight lines, so a curve is drawn as straight chords. Arc segments, shown for a pattern that has an arc, is the number of straight segments in a full circle: more segments follow the curve more closely and make the file larger. A .pat can only repeat along fixed line directions, so each chord is snapped onto one of the directions the pattern repeats along, which moves a chord end by a small distance; shorter chords (more segments) move less. A pattern whose edges are all parallel to its repeat directions, such as stack bond, is not snapped.

Should I download in millimetres or inches?
In the unit your drawing uses. The numbers in the file are in the unit you pick at the top of the page (mm or in), and the first line of the file records it. If the hatch comes out too big or too small, change the Scale in AutoCAD’s hatch settings.

What does it cost to use Hatchy?
One .pat download per UTC day needs no licence; a 3dshouse account is asked for at that first download. Further downloads that day need Hatchy Pro, a lifetime licence. Browsing patterns, editing and looking at the preview are never counted. This page states the terms in force when it was last updated.

Can I get the same pattern as a texture?
Yes, for patterns made of tiles. They are in the Texturic editor at 3dshouse.com/textures/, where a pattern becomes a seamless texture with PBR maps. Patterns made only of hatch lines have no texture.