PLINEGEN Explained: Linetype Patterns Across Polyline Vertices

PLINEGEN controls whether a non-continuous linetype is generated separately on each segment of a 2D polyline or continuously along the polyline as one object. It does not change the definition stored in the LIN file and it is not a replacement for the drawing-scale variables.

This distinction matters whenever a route contains many vertices. A dashed utility line can look almost continuous when every short segment restarts its own pattern, while the same polyline can show a clear, uninterrupted sequence when linetype generation is enabled.

What PLINEGEN Controls

The system variable establishes the default linetype-generation behavior for new 2D polylines. A value of 0 generates the pattern from vertex to vertex. A value of 1 treats the polyline length as a continuous path.

PLINEGEN does not normally rewrite existing polylines. Each existing object keeps its own Linetype generation property until that property is changed through Properties or PEDIT.

How Linetypes Normally Behave on Polylines

Separate Pattern on Each Segment

With segment-based generation, AutoCAD starts a fresh pattern at the beginning of every straight or arc segment. The endpoint treatment is therefore repeated at every vertex. Long segments can look acceptable, but short segments may show only a solid dash.

Continuous Pattern Across Vertices

With continuous generation, the pattern advances along the accumulated path length. A dash can pass through a vertex, and the next gap begins where the previous segment left off. This usually gives a more natural result for long routes and boundaries.

PLINEGEN Set to 0

Pattern Restarts at Every Vertex

Set PLINEGEN to 0 before creating a polyline when each segment should receive its own complete pattern. This can make vertices visually clear because AutoCAD places drawn portions near segment ends.

Effects on Short Polyline Segments

If a segment is shorter than a useful pattern cycle, there may not be enough room for a gap, dot, text label, or SHX symbol. Several short segments can therefore merge visually into a continuous line. This is a geometry problem described in the guide to linetypes on short lines, not proof that the LIN definition is missing.

PLINEGEN Set to 1

Pattern Continues Across Vertices

Set PLINEGEN to 1 before drawing a polyline when the route should display one continuous pattern. The setting is particularly useful for gas, water, electrical, fence, and boundary lines composed of many surveyed or designed vertices.

Effects at Corners

The pattern does not automatically rotate a text or shape to make every corner perfect. A long dash can cross a sharp corner, and a complex symbol can land close to a vertex. Test tight bends and adjust the pattern design when readability is more important than strict continuity.

System Variable vs. Polyline Property

Behavior for Newly Created Polylines

PLINEGEN is a creation default. After changing the variable, draw a new test polyline and assign the intended linetype. Existing objects are not a reliable test unless their object property is also changed.

Changing Existing Polylines

Select an existing polyline and change Linetype generation from Disabled to Enabled, or the reverse. This object-level setting remains with the polyline when it is copied to another drawing.

Change Linetype Generation in the Properties Palette

  1. Select one or more 2D polylines.
  2. Open Properties with Ctrl+1 or the platform-equivalent command.
  3. Locate Linetype generation.
  4. Choose Enabled for continuous generation or Disabled for segment-based generation.
  5. Run REGEN if the display does not update immediately.

If the property does not appear, confirm that the selected object is a supported 2D polyline rather than a collection of lines, a spline, or a 3D polyline.

Change Linetype Generation with PEDIT

Use PEDIT, select the polyline, and choose the Ltype gen option. Set it to On for continuous generation or Off for generation at each vertex. The Multiple option is useful when a project contains many polylines requiring the same correction.

PLINEGEN on Open and Closed Polylines

An open polyline has a clear start and end, so the pattern progresses in the polyline’s drawing direction. A closed polyline must also join at its closing vertex. The total perimeter may not contain an exact whole number of cycles, so the meeting point can show a shortened or visually uneven pattern.

For a closed property boundary, place the start vertex in a less prominent location when the pattern seam matters.

PLINEGEN on Polylines with Arc Segments

Continuous generation can pass from a straight segment into a polyline arc segment, but the pattern follows path length rather than chord length. Complex text and shapes can crowd on tight curves. The broader behavior of curved objects is covered in linetypes on arcs, circles, ellipses, and splines.

When PLINEGEN Improves the Drawing

Utility Lines

Text labels and symbols remain distributed along the full service route instead of restarting at every survey point or design vertex.

Boundaries

Fence, easement, and property patterns usually read more consistently when small directional changes do not reset the sequence.

Long Multi-Segment Routes

Road edges, cable paths, and alignment-like drafting polylines gain a uniform visual rhythm, particularly when vertices are close together.

When Segment-Based Patterns Are Better

Keep generation disabled when each segment represents a distinct component, when a dash must begin and end at every corner, or when symbols must not cross vertices. Segment-based generation can also make short, orthogonal detail geometry easier to interpret.

Common PLINEGEN Problems and Fixes

Symptom Likely cause Action
Changing PLINEGEN has no effect The polyline already existed. Change its Linetype generation property.
Property is unavailable The object is not a supported 2D polyline. Inspect or convert the geometry.
Symbols overlap at corners Pattern elements are too long for the bend. Use a compact variant or segment generation.
Pattern still looks solid Segments or the complete polyline are too short. Use the short-geometry diagnostic.
Model and layout differ Viewport scale variables are involved. Review PSLTSCALE and MSLTSCALE.

PLINEGEN Testing Checklist

  • Use the same linetype on two identical test polylines.
  • Disable generation on one and enable it on the other.
  • Include long, short, straight, and arc segments.
  • Test open and closed versions.
  • Reverse one polyline to evaluate complex text orientation.
  • Run REGEN and check model space, layouts, and PDF output.
  • Document the preferred setting in the company template or tool palette.

Related Linetype Guides