Surface Reconstruction From Triple Dexel Model for Virtual Sculpting

2007 ◽  
Author(s):  
Weihan Zhang ◽  
Ming C. Leu
Keyword(s):  
Differential Equation ◽  
Surface Reconstruction ◽  
Boundary Surface ◽  
Solid Modeling ◽  
Haptic Interface ◽  
Solid Model ◽  
Virtual Sculpting ◽  
Novel Method ◽  
Swept Volume ◽  
Differential Equation Method

This paper presents a novel method for surface reconstruction from triple dexel data for virtual sculpting. A triple dexel based virtual sculpting system is developed to provide the capability of interactive solid modeling with haptic interface. A solid model is converted to triple dexel data, which depicts the intersections of the solid with rays cast in three orthogonal directions, and modified during the virtual sculpting process. The boundary of the tool swept volume is computed based on the Sweep Differential Equation method. Contour generation and combination algorithms convert the triple dexel data to three sets of orthogonal slices of contours. A tiling algorithm then generates the solid’s boundary surface in triangular facets from these contours. Examples are given to demonstrate the ability of the developed method and software to realistically simulate the physical sculpting process and to allow viewing the sculpted models in any directions.

Surface Reconstruction From Dexel Data for Virtual Sculpting

2004 ◽  
Author(s):  
Xiaobo Peng ◽  
Weihan Zhang ◽  
Sai-Gowthami Asam ◽  
Ming C. Leu
Keyword(s):  
Surface Reconstruction ◽  
Cross Sections ◽  
Geometric Modeling ◽  
Ray Casting ◽  
Virtual Sculpting ◽  
Shortest Distance ◽  
Branching Problem ◽  
Volume Ray Casting ◽  
Swept Volume ◽  
Differential Equation Method

This paper presents a new method for surface reconstruction from dexel data for virtual sculpting. We are in the midst of developing a dexel model based sculpting system having the capability of interactive solid modeling with haptics interface. The geometric modeling of our sculpting system is based on the Sweep Differential Equation method to compute the boundary of the tool swept volume. Ray casting is used to perform Boolean operations between the tool swept volume and the virtual stock in dexel models to simulate the sculpting process. The dexel data are converted to a series of planar contours in parallel slices (i.e. cross sections). The overlapping ratio between two contour areas is used as the criterion for deciding on the corresponding contours in two adjacent slices. The tiling problem is tackled by using the rule of the shortest distance between points on two corresponding contours. The branching problem is solved by adding one line segment between two contours to form one composite contour. Examples are given to demonstrate the ability of the developed code to convert from dexel data to triangular meshes for the viewing of a sculpted model in different directions.

Solid Modeling of In-Process Workpiece Geometry for Hole Milling

2012 ◽  
Author(s):  
Jue Wang ◽  
Derek Yip-Hoi
Keyword(s):  
Cutting Forces ◽  
Tool Path ◽  
Solid Modeling ◽  
Solid Model ◽  
Virtual Machining ◽  
Solid Models ◽  
Milling Operation ◽  
Swept Volumes ◽  
Swept Volume ◽  
Physics Based Simulation

Capturing the in-process workpiece geometry generated during machining is an important part of tool path verification and increasingly the physics-based simulation of cutting forces used in Virtual Machining. Swept volume generation is a key supporting methodology that is necessary for generating these in-process states. Hole milling is representative of one class of milling operation where the swept volume is continuously intersecting. Due to this it is impossible to decompose the tool path into non-intersecting regions which is typically the approach used in solid model based swept volume generation. In this paper an approach to generating NURBS based solid models for self-intersecting swept volumes generated during hole milling is presented. NURB surfaces are generated that compactly represent the surfaces of the swept volume. This utilizes the geometry of the helical curve as opposed to a linearly interpolated tool path that is used for more generic approaches to generating swept volumes. Examples applying the approach to various types of cutter geometries used in milling are presented.

Surface Reconstruction Using Dexel Data From Three Sets of Orthogonal Rays

2009 ◽  
Vol 9 (1) ◽  
Author(s):  
Weihan Zhang ◽  
Ming C. Leu
Keyword(s):  
Surface Reconstruction ◽  
Boundary Surface ◽  
Numerical Control ◽  
Surface Model ◽  
Reconstruction Method ◽  
Virtual Sculpting ◽  
Marching Cube Algorithm ◽  
Voxel Representation ◽  
Reconstructed Surface ◽  
Representation Method

Triple-dexel modeling is a geometric representation method, which depicts the intersection of a solid with rays cast in three orthogonal directions. Due to its fast Boolean operations, simple data structure, and easy implementation, triple-dexel modeling is highly suitable for real-time graphics-based simulation applications such as numerical control (NC) machining verification and virtual sculpting. This paper presents a novel surface reconstruction method from triple-dexel data by first converting the triple-dexel data into contours on three sets of orthogonal slices and then generating the solid’s boundary surface in triangular facets from these contours. The developed method is faster than the voxel-based method, and the reconstructed surface model is more accurate than the surface reconstructed from voxel representation using the marching cube algorithm. Examples are given to demonstrate the ability of surface reconstruction from the triple-dexel model in virtual sculpting.

scholarly journals A Novel Method for Solving Nonlinear Volterra Integro-Differential Equation Systems

2018 ◽  
Vol 2018 ◽  
pp. 1-6 ◽  
Author(s):  
Mohammad Hossein Daliri Birjandi ◽  
Jafar Saberi-Nadjafi ◽  
Asghar Ghorbani
Keyword(s):  
Differential Equation ◽  
Differential Equations ◽  
Exact Solutions ◽  
Iteration Method ◽  
Spectral Collocation ◽  
Numerical Examples ◽  
Integro Differential Equation ◽  
Collocation Technique ◽  
Computational Work ◽  
Novel Method

An efficient iteration method is introduced and used for solving a type of system of nonlinear Volterra integro-differential equations. The scheme is based on a combination of the spectral collocation technique and the parametric iteration method. This method is easy to implement and requires no tedious computational work. Some numerical examples are presented to show the validity and efficiency of the proposed method in comparison with the corresponding exact solutions.

Disparity Surface Reconstruction Based on a Stereo Light Microscope and Laser Fringes

2018 ◽  
Vol 24 (5) ◽  
pp. 503-516
Author(s):  
Yuezong Wang
Keyword(s):  
Surface Reconstruction ◽  
Light Microscope ◽  
Stereo Matching ◽  
Block Matching ◽  
Stereo Image ◽  
Reference Plane ◽  
Motion Direction ◽  
Measuring Techniques ◽  
Novel Method ◽  
Disparity Contours

AbstractMicroscopic vision systems based on a stereo light microscope (SLM) are used in microscopic measuring fields. Conventional measuring methods output the disparity surface based on stereo matching methods; however, these methods require that stereo images contain sufficient distinguishing features. Moreover, matching results typically contain many mismatched points. This paper presents a novel method for disparity surface reconstruction by combining an SLM and laser measuring techniques. The surfaces of small objects are scanned by a laser fringe, and a stereo image sequence containing laser stripes is obtained. The central contours of the laser stripes are extracted, and central contours are derived for alignment. A disparity coordinate system is then defined and used to analyze the relationship between the motion direction and reference plane. Next, the method of aligning disparity contours is proposed. The results show that our method can achieve a precision of ±0.5 pixels and that the real and measured shapes described by the disparity surface are consistent based on our method. Our method is confirmed to perform much better than the conventional block-matching method. The disparity surface output obtained by our method can be used to measure the surface profiles of microscopic objects accurately.

scholarly journals Visualization of potential sink marks using thickness analysis of finely tessellated solid model

2018 ◽  
Vol 5 (4) ◽  
pp. 409-418
Author(s):  
Masatomo Inui ◽  
Shunsuke Onishi ◽  
Nobuyuki Umezu
Keyword(s):  
Thickness Distribution ◽  
Solid Model ◽  
Aesthetic Quality ◽  
Plastic Surface ◽  
Part Surface ◽  
Novel Method ◽  
Sink Marks ◽  
Automated Technique ◽  
The Aesthetic ◽  
Sink Mark

Abstract Sink marks are unwanted shallow depressions on the molded plastic surface caused by localized shrinkage during the hardening process of injection molding. Sink marks appearing in the exterior impair the aesthetic quality of the product. In this study, a novel method for extracting potential sink marks that can occur on the part surface is proposed. The thicker portion of the part shrinks with a greater amount than that of the thinner portion. This difference in the shrinkage amount is the main cause of the sink mark. In the plastic part design practice, engineers often check the thickness distribution to predict potential sink marks in the part surface. Our method can be considered as an automated technique of such manual inspection task. A polyhedral solid model of the part with sufficiently small triangles of nearly the same size is prepared. The amount of shrinkage at each polygon is estimated based on its thickness and the shrinkage ratio of the part. The developed algorithm extracts the potential sink marks by analyzing the shrinkage distribution on the part surface. Highlights A novel method for extracting potential sink marks on part surface is proposed. Polygons of input model are tessellated into a set of sufficiently small triangles. The shrinkage of each model polygon is estimated by using the thickness. Potential sink marks are extracted by analyzing the shrinkage distribution.

scholarly journals Exploiting Visibility Information in Surface Reconstruction to Preserve Weakly Supported Surfaces

2014 ◽  
Vol 2014 ◽  
pp. 1-20 ◽  
Author(s):  
Michal Jancosek ◽  
Tomas Pajdla
Keyword(s):  
Surface Reconstruction ◽  
Free Space ◽  
State Of The Art ◽  
The State ◽  
Real Object ◽  
Reconstruction Method ◽  
The Real ◽  
Model Free ◽  
Novel Method ◽  
Different Levels

We present a novel method for 3D surface reconstruction from an input cloud of 3D points augmented with visibility information. We observe that it is possible to reconstruct surfaces that do not contain input points. Instead of modeling the surface from input points, we model free space from visibility information of the input points. The complement of the modeled free space is considered full space. The surface occurs at interface between the free and the full space. We show that under certain conditions a part of the full space surrounded by the free space must contain a real object also when the real object does not contain any input points; that is, an occluder reveals itself through occlusion. Our key contribution is the proposal of a new interface classifier that can also detect the occluder interface just from the visibility of input points. We use the interface classifier to modify the state-of-the-art surface reconstruction method so that it gains the ability to reconstruct weakly supported surfaces. We evaluate proposed method on datasets augmented with different levels of noise, undersampling, and amount of outliers. We show that the proposed method outperforms other methods in accuracy and ability to reconstruct weakly supported surfaces.

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