AutoLISP Routines

You have inherited a drawing full of blocks whose contents were drawn on named layers in explicit colours. Every time you insert one it ignores the layer you put it on and appears in whatever colour it was built with. The correct fix is to have the block's contents on layer 0 with colour BYLAYER, so the block takes on the properties of wherever you insert it — but doing … [Read more...] about UPDBLOCK LISP: Change Layer or Colour Inside AutoCAD Blocks

Sometimes you need to trim a group of lines back to somewhere there is nothing to trim to. A line of columns cut off at a grid line that is not drawn, a set of hatching stopped at an imaginary edge, a bundle of services trimmed to a boundary you do not want in the drawing. The usual method is to draw a construction line, trim to it, then erase it. Three operations plus the … [Read more...] about TRX LISP: Trim to a Construction Line You Never Draw

Traverse reduces survey field notes into drawn points. You set up the instrument position and a backsight, then work through the observations, and it plots each point and numbers it — the arithmetic that turns a page of angles and distances into geometry, done for you. A second program then extracts the point numbers and coordinates back out, to screen, to a file or to a … [Read more...] about Traverse LISP: Reduce Survey Notes to Points in AutoCAD

Name: The 90 LISP Routine Collection Description: A heap of simple LISP routines. Get some programming ideas from this lot! Type: AutoCAD AutoLISP Routine Author: Various, see files for credits File Size: 192 Kb Cost: Free Worked on: AutoCAD Download File: 90lsp.zip … [Read more...] about The 90 LISP routine collection

Text on a drawing has to be sized for the plot, not for the model. Write 2.5 high text on a plan you intend to plot at 1:100 and it comes out at a fortieth of a millimetre on paper. The arithmetic is not hard — plotted height times scale factor — but doing it in your head every time you change scale is how drawings end up with four different text sizes on … [Read more...] about TEXTSIZE LISP: Work Out AutoCAD Text Height from Scale

TXP is a free routine for AutoCAD that explodes single-line TEXT entities into polylines. Its author, Ken, describes it as eliminating font garbage and overlapping or duplicate lines, and outputting clean open and closed polylines rather than a loose pile of segments: it eliminates font garbage and overlapping or duplicate lines, and outputs clean open and closed polylines … [Read more...] about TXP LISP Routine: Explode AutoCAD Text to Polylines