New 3DSolid TRIM and SPLIT commands.

The AutoCAD Visual LISP CheckInterference method can have many uses besides that of checking for possible interferences. The tutorial in section 18.9 of my book "AutoCAD expert's Visual LISP" adds two new 3DSolid editing commands to AutoCAD. These will reproduce the functionality of the Solid modeling tools TRIM and SPLIT introduced in Sketchup PRO version 8.

The TRIM tool allows picking 3DSolids as the trimming objects and a set of overlapping 3DSolids from which the overlapping portion will be removed without deleting the trimming solid as would be the case if a SUBTRACTION operation was performed.

The SPLIT command is more elaborate, as it will create separate 3DSolids wherever the solids overlap.

In both cases the trick will be to use the Interference solid, as this way none of the Solids on which the command operates will be lost, they will be modified applying Boolean operations using the Interference solid.

This App is available at AutoCAD Exchange. More info in my blog lispexpert.blogspot.com

i was expecting a LISP or summat to load.

no idea what to do with that and nothing happened when i clicked the unzipped files. i hope it wasn't a virus

Assuming for the moment that the unzipped file yield one or two lisp or vlx files did you attempt to load them using the APPLOAD command?

I am not on my CAD computer at the moment and have not downloaded the zip file.

i got 1 x .fas file 3k in size

off to google what .fas is, but i was hoping for a LISP - looked handy

i got 1 x .fas file 3k in size

 

off to google what .fas is, but i was hoping for a LISP - looked handy

A fas file is a "protected" lisp file that you can not edit, load it like any other lsp file.

Hi, don't worry it's not a virus... just a FASt-loading AutoLISP file. Try simply dragging it to your graphic window. An alert window will open showing the new command names: STRIM and SSPLIT. Try them on several overlapping 3DSolids.

With STRIM, you must select a group of solids as trimming objects and a different set as solids to be trimmed. They should overlap somehow.

Without this command you would have to make a copy of the trimming solids so when using the SUBTRACT operation these solids would not be lost. This new command for which I took the Idea from Sketchup 8 just saves you time.

The other one, SSPLIT is does something that might be more unusual, given a set of overlapping 3D Solids it will create different solids for each overlapping section. It also reproduces the behavior of a new Sketchup solid editing command.

My intention in the book is only to demonstrate ways of using the CheckInterference method, but I realize they might come in handy when working with 3D Solids.