CSG Editor, Version 2.1

DN Staff

October 20, 1997

4 Min Read
CSG Editor, Version 2.1

Although AutoCAD R13 offers a wealth of advantages over R12, I've noticed the reluctance of some to upgrade. One reason for this reluctance seems the most pervasive. R13 doesn't provide editing tools to modify solid models created using constructive solid geometry (CSG) techniques--a particularly bothersome deficiency since R12's AME had this capability.

CSG Editor efficiently solves this problem at a reasonable price. An AutoCAD Runtime Extension (ARX) application, CSG Editor blends easily into the R13 environment, trapping solid modeling commands and saving the data needed to modify primitives at a later time.

CSG Editor can modify any parameter of R13's solid primitives (box, cone, cylinder, sphere, torus, and wedge) at any level of a CSG construction tree.

Solids created by extruding or revolving 2-D profiles may be edited, changing profile, path or height, and draft angle for extrusions, and changing profile, axis, and angle for revolutions.

Once a solid is selected for editing, a primitive may be selected directly, or selection may be cycled through the primitives until the desired one is reached. In addition to editing primitive parameters, a primitive may be copied, deleted, moved, replaced, or changed in color. The CSG Editor move command is powerful, permitting redefinition of the current UCS, and then rotating or translating in this temporary UCS.

CSG Editor modifies standard R13 chamfers and fillets, and provides its own versions of chamfer and fillet commands to simplify the editing process. Although chamfers and fillets in a CSG modeler can often be difficult to edit (the reference edges can move during other edits), CSG Editor makes these editing operations as simple as possible. If a reference edge has moved, the Editor permits reselection of the edge to complete the chamfer or fillet.

I found the CSG Array command particularly useful. It simplifies the construction and editing of hole patterns and other repeated geometry. A pattern created with this command can be edited as a single entity, for example, you can change the number of holes in a pattern; or all repeated features can be edited with a single modification of the parent solid (a cylinder, say, for a hole pattern). Patterns can be generated from a complex solid, making this tool very flexible.

The Editor offers two means of separating the primitives of a complex solid. The first totally decomposes a solid, extracting all primitives and deleting the original solid. The second extracts primitives, one at a time, beginning with the most recently added.

For those with an existing database of R12 AME solids, CSG Editor offers a translator which generates editable R13 solids from the old models.

Documentation is well written and complete. A short tutorial provides sufficient instruction to use CSG Editor efficiently. Menu text is included to easily integrate the new CSG Editor commands into the existing AutoCAD menu structure. CSG construction alternates are available as LISP commands.

CSG Editor adds a solid's construction trail as extended entity data. This data can be stripped by exporting a solid to a SAT file, then importing the SAT file.

CSG Editor is an elegant solution to an important need. With its addition, R13 is clearly superior to R12, and the only viable objection to upgrading is eliminated. Anyone creating AutoCAD R13 solids with CSG techniques will benefit from CSG Editor.

Note: CSG Editor Version 3 for AutoCAD R14 became available as of press time. It offers the same advantages the earlier version brought to R13 with the addition of very easy installation, toolbar icons, and clear dialogs. The new version fits well with R14's improved user interface, and makes the combination an easy-to-use, powerful solid modeler.


Spec Box

CSG Editor

This AutoCAD add-on provides extensive editing capability for solids created using constructive solid geometry (CSG) techniques. It is compatible with AutoCAD R13, C4 or higher, and R14. CSG Editor integrates transparently into the AutoCAD environment, offering new solids editing commands when needed. Solids created with CSG Editor installed can be processed by any AutoCAD command accepting solid entities.

List Price: $295

Context CAD, Inc.
103 Lincoln Dr.
Sausalito, CA 94965
ph: 800-840-8050.

A similar product: AutoCAD R12 AME Solids Editor
Autodesk Inc.
111 McInnis Pkwy.
San Rafael, CA 94903
ph. (415) 517-5000

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