Browse Prior Art Database

Interactive Simplification of Solid Models

IP.com Disclosure Number: IPCOM000111869D
Original Publication Date: 1994-Apr-01
Included in the Prior Art Database: 2005-Mar-26
Document File: 4 page(s) / 114K

Publishing Venue

IBM

Related People

Masuda, H: AUTHOR [+2]

Abstract

This article describes a method to change a complicated solid model into a relatively simple solid model by ignoring detail.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 52% of the total text.

Interactive Simplification of Solid Models

      This article describes a method to change a complicated solid
model into a relatively simple solid model by ignoring detail.

      Solid models are useful to support design activities, process
planing, and so on.  Especially, solid models are known as the most
powerful input data for engineering analysis systems, which need 3D
shaped data of products.  However, it is also known that solid models
created in design phase are often too complicated for analysis.
Solid models define geometric shapes of products in detail, but
analysis systems do not always need detailed information.  In
addition, if solid models are very complicated, analysis may fail
because of numerical errors, and it takes a lot of time to get the
result of the analysis.  Therefore, it is necessary to simplify
complicated solid models for engineering analysis and simulation.

      The new idea enables the designer to simplify complicated solid
models by trial-and-error.  To realize this trial-and-error
simplification, the following techniques are introduced.

o   Representation of solids by means of cell decomposition models.

o   Quick extraction of simplified solid models from the cell
    decomposition model.

o   Selection of form-features by using the attributes or geometric
    characteristics.

      Fig. 1 shows the system structure.  Fig. 1 (a) shows a
feature-based geometric modeling system, which defines solid models
by means of form-features such as grooves, steps, holes, and so on.
Examples of form-features are shown in Fig. 2.  In form-feature
modeling, designers create solid shapes by specifying the types and
location of features.  Specified form-features are embedded in a
modeling space and subdivide the space into cells.  Fig. 3(a) shows
three cells, C1, C2, and C3 subdivided by form-features.  An
important merit of the use of decomposition models is that various
solid models are easily created by selecting some of the
form-features.  Fig. 3 shows two solid models generated from a cell
decomposition model.  In Fig. 3(b), C1, C2, and C3 are selected to
define a solid, and in Fig.  3(c), C1 and C3 are selected.  Since
solid models consist of faces that are adjacent to only one selected
cell, they can be very quickly generated by searching adjacent
relationships between cel...