This paper presents a methodology to create 3D visualization from discrete event simulation for simulation of electronics assembly processes. The methodology connects discrete event simulation directly to 3D animation with its novel methods of converting discrete simulation results into animation events to trigger 3D animation. It also develops a 3D animation framework for the visualization of discrete simulation results. This framework supports the reuse of both the existing 3D animation objects and behaviour components, and allows the rapid development of new 3D animation objects by users with no special knowledge in computer graphics. This methodology has been implemented with the software component technology. Examples are presented to demonstrate the efficiency of the proposed methodology.

This paper presents a vision-based approach for valid assessment of surface roughness in both micro-scale and nano-scale regions. To enable data comparisons, three sets of surface data in the micro and nano regions are acquired by using a CCD camera, a video-based optical microscope and a stylus instrument. Data filtering and analysis procedures are applied to the acquired data. Results for computation of roughness parameters by using vision data provide adequate values for assessment of surface roughness in the manner as similar as stylus based technique. No obvious changes in the computed roughness parameter values are resulted from the micro and nano regions. In the nano region, a cavity graphs technique provides distinguishable forms of graphs that tend to more gradual increase of the cavity percentage to denote the collection of the macro surface details. In addition, an auto correlation technique applied in the nano region succeeds to discriminate the surface irregularities relationship with respect to their periodicity and randomness. The overall acquired results indicate that vision systems are a valid source of data for reliable surface roughness evaluation in both micro/nano-scale regions. The results are very useful in achieving commercial 3D vision based micro-nano roughness measurement systems for industrial applications.

This paper presents a new methodology to simulate soft object deformation by drawing an analogy between a cellular neural network (CNN) and elastic deformation. The potential energy stored in an elastic body as a result of a deformation caused by an external force is propagated among mass points by a nonlinear CNN. The novelty of the methodology is that: 1) CNN techniques are established to describe the potential energy distribution of the deformation for extrapolating internal forces and 2) nonlinear materials are modeled with nonlinear CNNs rather than geometric nonlinearity. Integration with a haptic device has been achieved for deformable object simulation with force feedback. The proposed methodology not only predicts the typical behaviors of living tissues, but it also accommodates isotropic, anisotropic, and inhomogeneous materials, as well as local and large-range deformation.

This paper presents a new methodology for the deformation of soft objects by drawing an analogy between heat conduction and elastic deformation. The potential energy stored in an elastic body as a result of a deformation caused by an external force is propagated among mass points by the principle of heat conduction. An improved heat conduction model is developed for propagating the energy generated by the external force in a natural manner. A method is presented to derive the internal forces from the potential energy distribution. This methodology not only deals with large-range deformation, but also accommodates both isotropic and anisotropic materials by simply changing thermal conductivity constants. Examples are presented to demonstrate the efficiency of the proposed methodology.

This paper presents a methodology to create 3D visualization of discrete event simulation. This methodology connects discrete event simulation directly to 3D animation with its novel methods of analyzing and converting discrete simulation results into animation events to trigger 3D animation. Discrete simulation results are analyzed and displayed in a graph structure that reveals all possible sequences of simulation events. In addition, a 3D animation framework is constructed for the visualization of discrete simulation results. This framework supports the reuse of both the existing 3D animation objects and behavior components, and allows the rapid development of new 3D animation objects by users with no special knowledge in computer graphics. This methodology has been implemented with the software component technology. Results in an electronics assembly factory are also provided in the paper to demonstrate the feasibility of this approach.

A hierarchically structured constraint-based data model for solid modelling in a virtual reality environment is presented. The data model integrates a high-level constraint-based model for precise object definition, a mid-level CSG/Brep hybrid solid model for supporting hierarchical geometry abstractions and object creation, and a low-level polygon model for real-time visualization and interaction in the virtual reality environment. Constraints are embedded in the solid model and organized at different levels to reflect the entire solid modelling process from features and parts, to assemblies. This model not only provides precise object definition, but also supports real-time visualization and interaction in the VR environment. Furthermore, it has the potential to obtain precise 3D interactions and precise constraint-based manipulations can be deduced from the data model to carry out precise solid modelling in the VR environment.

The absence of constraints is one of the major limitations in current Virtual Reality (VR) environments. Without constraints, it is difficult to perform precise 3D interactive manipulations in VR environments and precise solid modelling in VR environments cannot be guaranteed. In this paper, constraints are incorporated into the VR environment for intuitive and precise solid modelling. A hierarchically structured constraint-based data model is developed to support solid modelling in the VR environment. Solid modelling in the VR environment is precisely performed in an intuitive manner through constraint-based manipulations. Constraint-based manipulations are accompanied with automatic constraint recognition and precise constraint satisfaction to establish the hierarchically structured constraint-based data model and are realized by allowable motions for precise 3D interactions in the VR environment. The allowable motions are represented as a mathematical matrix for conveniently deriving allowable motions from constraints. A procedure-based degree-of-freedom incorporation approach for 3D constraint solving is presented for deriving the allowable motions. A rule-based constraint recognition engine is developed for both constraint-based manipulations and implicitly incorporating constraints into the VR environment. A prototype system has been implemented for precise solid modelling in an intuitive manner through constraint-based manipulations in the VR environment.

With today's virtual reality systems, it is difficult to directly and precisely create and modify complex objects in a virtual reality environment. One of the most important reasons is the absence of a suitable model representation that can efficiently support solid modelling in a virtual reality environment. A hierarchically structured constraint-based data model for solid modelling in the virtual reality environment is presented in this paper. The data model integrates a high-level constraint-based model for precise object definition, a mid-level CSG/B rep hybrid solid model for supporting hierarchical geometry abstractions and object creation, and a low-level polygon model for real-time visualization and interaction in the virtual reality environment. Constraints are embedded in the solid model and are organized at different levels to reflect the process of solid modelling. This data model not only provides precise object definition, but also supports real-time visualization and interaction in the virtual reality environment.