Construction of Freeform Feature Models With Attachments

2004 ◽  
Author(s):  
Eelco van den Berg ◽  
Rafael Bidarra ◽  
Willem F. Bronsvoort
Keyword(s):  
Feature Modeling ◽  
Geometric Constraints ◽  
Feature Model ◽  
Feature Models ◽  
Construction Methods ◽  
Modeling Systems ◽  
Model Geometry ◽  
New Feature ◽  
Current Feature

In freeform feature modeling, the shape domain of current feature modeling systems is extended with freeform shapes. A challenging task in this context is to develop a method for constructing a feature model in an intuitive, yet unambiguous manner, comparable to the construction methods for regular-shaped feature models. This paper describes a framework in which it is possible to attach a face of a new freeform, volumetric feature instance to a face of a feature instance already in the model. In this framework, features are represented by configurations of freeform definition points, from which the shape is generated. By using geometric constraints on these definition points and other geometric entities within the model, freeform attachments can be realized. Apparent problems that emerge in this context are positioning of the new feature instance on the freeform attach face, fitting the geometry of the new feature instance to the existing model geometry, and maintenance of valid feature model geometry. The framework accommodates for these issues. Two types of attachment, for a freeform extrusion feature respectively a freeform wrap feature, are elaborated. With the attachments presented here, freeform feature models can be constructed in a fully parametrized, constraint-based way, just like regular-shaped feature models.

History-Independent Boundary Evaluation for Feature Modeling

1999 ◽  
Author(s):  
Rafael Bidarra ◽  
Willem F. Bronsvoort
Keyword(s):  
Geometric Modeling ◽  
Geometric Model ◽  
Computational Cost ◽  
Feature Modeling ◽  
Boundary Representation ◽  
Feature Model ◽  
Cellular Model ◽  
Boundary Evaluation ◽  
Modeling Systems ◽  
Current Feature

Abstract Most current feature modeling systems strongly rely on a history-based interpretation of the feature model, in order to maintain its evaluated boundary representation. This dependency on the model history is undesirable, as it forces the user of the modeling system to reason in terms of a strict chronological feature creation order. Moreover, re-evaluation of the boundary representation, as performed in such systems, has a computational cost proportional to the size of the model history. Such drawbacks suggest that current feature modeling systems are still too tied to conventional geometric modeling techniques. In this paper, it is argued that to overcome the drawbacks mentioned above, a declarative feature model is required, whose structure is dynamically adapted as modeling operations create or modify relations among its features. Operations performed on this feature model can then be efficiently propagated to an evaluated non-manifold geometric representation, without invoking model history considerations. The paper describes how such a geometric model — the so-called Cellular Model — can be maintained throughout model evolution. For each modeling operation, this is achieved in two phases. First, the Cellular Model is incrementally re-evaluated. Second, the Cellular Model is interpreted, according to the feature information stored in its cellular entities and the current dependencies among the features. The advantages of the use of this history-independent boundary evaluation, implemented within the semantic feature modeling approach, are illustrated with some modeling examples.

An Interactive Graphical Approach to Feature Modeling Using Halfspaces and Geometric Constraints

1990 ◽  
Author(s):  
Maarten J. G. M. van Emmerik
Keyword(s):  
Spatial Relations ◽  
Feature Modeling ◽  
Geometric Constraints ◽  
Boolean Combination ◽  
Graphical Approach ◽  
Geometric Characteristics ◽  
Feature Based ◽  
New Feature ◽  
High Level ◽  
And Control

Abstract Feature modeling enables the specification of a model with standardized high-level shape aspects that have a functional meaning for design or manufacturing. In this paper an interactive graphical approach to feature-based modeling is presented. The user can represent features as new CSG primitives, specified as a Boolean combination of halfspaces. Constraints between halfspaces specify the geometric characteristics of a feature and control feature validity. Once a new feature is defined and stored in a library, it can be used in other objects and positioned, oriented and dimensioned by direct manipulation with a graphics cursor. Constraints between features prevent feature interference and specify spatial relations between features.

A Collaborative Feature Modeling System

2002 ◽  
Vol 2 (3) ◽  
pp. 192-198 ◽  
Author(s):  
Rafael Bidarra ◽  
Eelco van den Berg ◽  
Willem F. Bronsvoort
Keyword(s):  
Feature Modeling ◽  
Feature Model ◽  
Model Specification ◽  
Web Based ◽  
Collaborative Modeling ◽  
Multiple User ◽  
Modeling Systems ◽  
The One ◽  
Research Challenge ◽  
Server Architecture

Collaborative systems are distributed multiple-user systems that are both concurrent and synchronized. An interesting research challenge is to develop a collaborative modeling system that offers all facilities of advanced modeling systems to its users, while at the same time providing them with the necessary coordination mechanisms that guarantee effective collaboration. To achieve this, a web-based collaborative feature modeling system, webSpiff, has been developed. It has a client-server architecture, with an advanced feature modeling system as a basis for the server, providing feature validation, multiple views and sophisticated visualization facilities. A careful distribution of the functionality between the server and the clients has resulted in a well-balanced system. On the one hand, the server offers all the functionality of the original feature modeling system. On the other hand, all desirable interactive modeling functionality is offered by the clients, ranging from display of feature model images to interactive model specification facilities. The architecture of webSpiff, the distribution of model data, the functionality of the server and the clients, and the communication mechanisms are described. It is shown that a good compromise between interactivity and network load has been achieved, and that indeed advanced feature modeling with a collaborative system is feasible.

Feature Validation in a Multiple-View Modeling System

1996 ◽  
Author(s):  
Maurice Dohmen ◽  
Klaas Jan de Kraker ◽  
Willem F. Bronsvoort
Keyword(s):  
Object Oriented ◽  
Feature Modeling ◽  
Feature Model ◽  
Feature Models ◽  
New Approach ◽  
Multiple View ◽  
Feature Parameters ◽  
Constraint Graph ◽  
Geometry Feature ◽  
Model Features

Abstract A new approach to specification and maintenance of feature validity conditions in a multiple-view feature modeling system is presented. Each view of a product contains a feature model. Features are specified declaratively in an object-oriented language, using constraints to specify feature validity conditions. Constraints are also used to specify relations between features. Validation of the feature models is done by a constraint manager that integrates different solving techniques. The constraint graph is mapped by the constraint manager onto constraints that are handled by dedicated solvers. If views are consistent, i.e. their feature models represent the same geometry, feature parameters can be changed. Changes are propagated through link constraints between different views.

Collaborative Modeling With Features

2001 ◽  
Author(s):  
Rafael Bidarra ◽  
Eelco van den Berg ◽  
Willem F. Bronsvoort
Keyword(s):  
Feature Modeling ◽  
Feature Model ◽  
Model Specification ◽  
Web Based ◽  
Collaborative Modeling ◽  
Multiple User ◽  
Modeling Systems ◽  
The One ◽  
Research Challenge ◽  
Server Architecture

Abstract Collaborative systems are distributed multiple-user systems that are both concurrent and synchronized. An interesting research challenge is to develop a collaborative modeling system that offers all facilities of advanced modeling systems to its users, while at the same time providing them with the necessary coordination mechanisms that guarantee an effective collaboration. To achieve this, a web-based collaborative feature modeling system, webSPIFF, has been developed. It has a client-server architecture, with an advanced feature modeling system as a basis for the server, providing feature validation, multiple views and sophisticated visualization facilities. A good distribution of the functionality between the server and the clients has resulted in a well-balanced system. On the one hand, the server offers all the functionality of the original feature modeling system. On the other hand, all desirable interactive modeling functionality is offered by the clients, ranging from display of sophisticated feature model images to interactive model specification facilities. The architecture of webSPIFF, the distribution of model data, the functionality of the server and the clients, and the communication mechanisms are described. It is shown that a good compromise between interactivity and network load has been achieved, and that indeed advanced modeling with a collaborative system is feasible.

An Interactive Graphical Approach to Feature Modeling Using Halfspaces and Geometric Constraints

1990 ◽  
Author(s):  
Maarten J. G. M. van Emmerik
Keyword(s):  
Spatial Relations ◽  
Feature Modeling ◽  
Geometric Constraints ◽  
Boolean Combination ◽  
Graphical Approach ◽  
Geometric Characteristics ◽  
Feature Based ◽  
New Feature ◽  
High Level ◽  
And Control

Abstract Feature modeling enables the specification of a model with standardized high-level shape aspects that have a functional meaning for design or manufacturing. In this paper an interactive graphical approach to feature-based modeling is presented. The user can represent features as new CSG primitives, specified as a Boolean combination of halfspaces. Constraints between halfspaces specify the geometric characteristics of a feature and control feature validity. Once a new feature is defined and stored in a library, it can be used in other objects and positioned, oriented and dimensioned by direct manipulation with a graphics cursor. Constraints between features prevent feature interference and specify spatial relations between features.

Automatic Detection of Interactions in Feature Models

1997 ◽  
Author(s):  
Rafael Bidarra ◽  
Maurice Dohmen ◽  
Willem F. Bronsvoort
Keyword(s):  
Feature Interaction ◽  
Feature Models ◽  
New Approach ◽  
Feature Interactions ◽  
Modeling Process ◽  
Modeling Systems ◽  
Feature Based ◽  
Interaction Constraints ◽  
Current Feature ◽  
Interaction Management

Abstract Current feature-based modeling systems fail to adequately maintain feature semantics. This is partly due to inappropriate specification of validity conditions in feature classes, but mainly due to a lack of effective validity maintenance mechanisms throughout the modeling process. A critical aspect in this is feature interaction management. This paper presents a new approach to the detection of feature interactions, which uses semantic and interaction constraints in feature class specification. Validity maintenance is automatically performed after each modeling operation by checking these constraints, thus being able to detect a variety of interaction types. Such interactions are then analyzed, and their causes identified and reported to the user.

Enforcing Model Validity by Automatic Adjustment

2001 ◽  
Vol 1 (4) ◽  
pp. 311-319 ◽  
Author(s):  
Alex Noort ◽  
Willem F. Bronsvoort
Keyword(s):  
Feature Modeling ◽  
Feature Model ◽  
Constraint Solving ◽  
Critical Dimensions ◽  
Model Validity ◽  
Modeling Systems ◽  
Different Types ◽  
Model Adjustment ◽  
Adjustment Strategies ◽  
Feature Conversion

In current modeling systems, all dimensions in a model have to be fully specified by the user. It is desirable that systems become more flexible in this respect, i.e. that non-critical dimensions in a model can be declared variant, and that the model can be automatically adjusted to enforce its validity when it is invalid. A method to realize this in feature modeling systems is described. The underlying feature model definition and validation approach are introduced. Validation is done by a collection of constraint solvers. An overview of invalid situations in which automatic model adjustment can be applied is given. The constraint solving scheme and, in particular, the automatic model adjustment strategies for different types of constraints are elaborated. Applications to enforce model validity are given for the areas of design by features, creating a member of a family of products, and feature conversion. These illustrate that automatic model adjustment is a very useful concept.

scholarly journals Context modeling based on feature models expressed as views on ontologies via mappings

2015 ◽  
Vol 12 (3) ◽  
pp. 961-977 ◽  
Author(s):  
Sinisa Neskovic ◽  
Rade Matic
Keyword(s):  
Contextual Information ◽  
Product Line ◽  
Feature Model ◽  
Local Context ◽  
Context Modeling ◽  
Feature Models ◽  
Context Model ◽  
Global Context ◽  
Software Product ◽  
Global And Local

This paper presents an approach for context modeling in complex self adapted systems consisting of many independent context-aware applications. The contextual information used for adaptation of all system applications is described by an ontology treated as a global context model. A local context model tailored to the specific needs of a particular application is defined as a view over the global context in the form of a feature model. Feature models and their configurations derived from the global context state are then used by a specific dynamic software product line in order to adapt applications at runtime. The main focus of the paper is on the realization of mappings between global and local contexts. The paper describes an overall model architecture and provides corresponding metamodels as well as rules for a mapping between feature models and ontologies.

Sign in / Sign up

Export Citation Format

Share Document