4. Computer-Aided Design and Drafting (CADD) Profile

Intended Use --

The purpose of a generic CADD profile to SDTS is to support the exchange, transfer, and archive of CADD spatial data. It is intended for CADD users who are doing GIS-type activities. It is not needed for CADD data which does not have geospatial data requirements.

The CADD profile may require the use of SDTS arcs (i.e., mathematically defined curves such as circles and splines) in addition to other vector elements. Topological relationships may not be required. 3-D volume elements and other unique CADD elements may be required.

Primary Sponsors, Interested Groups, and Contacts --

The FGDC Facilities Working Group and the U.S. Army Corps of Engineers through the DOD Tri-Service CADD/GIS Technology Center are the primary sponsors of the CADD Profile. The Tri-Service Center is working with Cordant, Application Software Technologies (AST), and Intergraph on initial investigations of a CADD Profile. Additional interest in a CADD profile has come from AutoDesk.

Documents --

"Scope of Work" contracts for the SDTS CADD Profile were awarded by the Tri-Service group to Cordant and to Intergraph in late 1995. The 1996 reports "Development of a Spatial Data Transfer Standard (SDTS) Profile for the Translation of MicroStation CADD Elements" from Intergraph and "Development of a Spatial Data Transfer Standard (SDTS) Profile for Translation of AutoCAD CADD Elements" from AST are available on the FGDC Facilities Working Group data standards site at

http:/ /corps_geo1.usace.army.mil/FGDC/data_standards.html

The October 1996 proposal for a CADD profile is available at

http://www.fgdc.gov/pub/standards/CADD/procadd.txt

The CADD Profile has passed the first 3 of the 12 steps for formal FGDC approval, and a project to develop the profile has been endorsed by the FGDC Standards Working Group (SWG). Information on the status the CADD Profile is available from the FGDC SWG site at

http://www.fgdc.gov/SWG

The August 1997 document "SDTS CADD Profile: for Tri-Service CADD/GIS Center" from Aztech Corp. is available at

http://corps_geo1.usace.army.mil/FGDC/Facility/sdtscadd.pdf.

This document will be sent to the FGDC Standards Working Group from the FGDC Facilities Working Group to begin the review process.

Future Plans --

ANSI approval will be considered after FGDC approval.

The role of an SDTS CADD Profile in relationship to ANSI IGES, PDES/STEP, and ISO 10303 should be investigated. A CADD profile to SDTS should have an easy translation to PDES-STEP/CADD. The extension of PDES to accommodate GIS through an ISO 10303 application protocol for GIS has been mentioned. The DWG graphics file format has also been mentioned as a possible industry standard for geospatial and CAD data.

A January 1996 A/E/C Systems article indicates that an object-based model is recommended for CAD data exchange. Additional investigation is needed to determine how the proposed CADD profile may be similar to the proposed SDTS object-based profile and nontopological vector profile.