Browse Prior Art Database

Extraction and Reuse of Partial Forms on 3D Solid Models Generated with Geometric Constraints

IP.com Disclosure Number: IPCOM000114568D
Original Publication Date: 1995-Jan-01
Included in the Prior Art Database: 2005-Mar-29
Document File: 2 page(s) / 52K

Publishing Venue

IBM

Related People

Numao, M: AUTHOR [+3]

Abstract

A system is disclosed that extracts and reuses partial forms on 3D solid modeler that has Constructive Solid Geometry (CSG) and geometric constraints as its form description. Extracted form data are stored at two levels: abstract level to reuse flexibly, and precise level to minimize the calculation on reuse.

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Extraction and Reuse of Partial Forms on 3D Solid Models Generated
with Geometric Constraints

      A system is disclosed that extracts and reuses partial forms on
3D solid modeler that has Constructive Solid Geometry (CSG) and
geometric constraints as its form description.  Extracted form data
are stored at two levels: abstract level to reuse flexibly, and
precise level to minimize the calculation on reuse.

      A solid model has a CSG tree and geometric constraints.  By
regarding the geometric constraints as links, and geometric elements
that constitute the solid primitives for CSG as nodes, the solid
model is described as a graph structure.

      To extract the form to be reused, users define it by simply
specifying the part in the current model.  The system first extracts
the CSG sub-tree and relevant geometric constraints.  Next, it
maintains constraints between the original model and the extracted
part as the interface, and encapsulates the rest.  Then, it holds the
data as a reusable component as shown in the Figure.  The system also
maintains the solid model data of the extracted form, and the data of
the geometric elements of the original model that have links with the
interface, to minimize the calculation for restoring as follows.

To restore the form, users respecify as the interface the geometric
constraints that are visible.

      The system first checks if the relative positions among the
geometric elements which are connected with th...