GPU-based discrepancy check for 3 D fabrication

For the processing of data such as with 3D printing, Virtual Reality (VR) and Augmented Reality (AR), there is a need to seek technology which accurately and quickly analyzes the three-dimensional structures including that of complicated 3D forms. However, unlike in 2D situations when there are few data points, there is not yet an established method for processing it quickly for 3D forms due to the fact the objects constructing it are complicated as well as the fact that there is a lot of data points within the space. Generally, when illustrating a complicated form, a method is used whereby an object with the complicated form is generated using several primitive shapes. This method is used in various 3D modelling software because the position of the object can be intuitively and freely changed and since it can be easily written within DirectX or Java 3D, OpenGL, etc. In this thesis, it was shown that by using GPGPU (General-Purpose computing on Graphics Processing Units) in respect of an algorithm with a solid angle, the inside-outside judgement could be conducted quickly. Specifically, a measurement of inside-outside judgement processing was made for complicated shapes created from several primitive shapes as well as the measurement of processing time of several primitive shapes.

1990

Sculpt, an interactive polyhedral solid modeling system, combines the effectiveness of BSP trees for performing geometric search, set operations, and determination of visibility, with the rendering performance of the AT&T Pixel Machines to provide interactive SCUlpting of texture mapped solids. The paradigm presented to the user is one in which a tool is used to modify a workpiece repeatedly by set operations (union, difference, or intersection). The user may choose between performing one set operation at a time with repositioning of the tool between operations, or sweeping the tool during which either union or difference is performed "continuously" (at sampled tool positions). Solid near-plane clipping is also provided using a BSP tree clipping algorithm. The user interface is simple and was designed to allow portability to a variety of workstations. Update rates using a Sun 3(260 and a Pixel Machine 964 for texture mapped models of-1000 polygons require-0.2 secs per update when using a simple tool.

In order to prevent heritage and important sites, an inspection was carried out to identify different tools and techniques for 3D modeling. It was observed that a good quality work is done all over the world, related to 3D modeling. Different tools and techniques where adopted by different researchers along which different data acquisition were used. It was studied that different tools are suitable to work with different type of 3D model generation.

Proceedings of the 11th Joint Conference on Computer Vision, Imaging and Computer Graphics Theory and Applications, 2016

The numerical simulation of phenomena requires a good quality discretization (mesh) of the domain. Depending on the problem to be simulated, the mesh has to fulfil different quality criteria. Because of geometry restrictions or point density requirements, several mesh elements might not satisfy the required quality criteria and sometimes it is also not required that all elements fulfil them. Then, it would be helpful to know where unwanted elements are located in order to see if they need to be repaired or not. That is why a visualization tool that allows the user to inspect a mesh before a simulation is performed can be useful to prevent simulation problems. Moreover, if data from simulations is available, the visualization of geometrical properties together with simulation data could be also helpful to understand not expected results. These challenges have motivated us to develop Camarón, a visualization tool for large surface and volume meshes described in this paper. The surface meshes can be composed any polygonal cell and the 3D meshes can include any convex polyhedral cell. This tool was implemented in C++ and the OpenGL Shading Language (GLSL). We discuss the design and implementation issues that make our software portable, extensible and different from other visualization tools. We also compare the performance between Camarón and GeomView, TetView and MeshLab.

Computer-Aided Design and Applications, 2013

The use of 3D CAD in mechanical product design has become a standard practice. Consequently, methods and tools are continually being developed to improve designers' efficiency in the creation, modification and analysis of 3D CAD models. Recent software developments had led to the emergence of multiple tools capable of comparing 3D CAD models to locate shape similarities or differences, leading to benefits in various CAD-and PLM-related application domains such as design reuse, data exchange and engineering change management. This paper describes evaluation trials that were performed on sets of commercially available 3D CAD model comparison tools. The goal was to evaluate their capacity to efficiently calculate, represent and display 3D CAD model differences in shape change transposition scenarios where shape modifications must be precisely located and elaborated in order to be consistently propagated between application-specific models of a product. First, some basic concepts of 3D CAD model comparison are presented. Then, simulated shape change assessment scenarios are defined to pilot two series of evaluation trials intended for existing software tools capable of comparing 3D CAD procedural and explicit models, respectively. The results are summarized and conclusions are drawn.

2020

Many different applications of product inspections have found a significant advantage by the use of 3D-scanners, especially when working with complex surfaces, where traditional inspection tools have significant limitations. This work deals with the structured light 3D-scanning based on fringe-pattern and obtaining polygonal mesh models (stl-models) of several end-and half-products, manufactured by different operations of blank production. In the study, the preparing of point clouds are discussed as well. 3D-scanning is possible to apply for getting the high resolution and accurate results for both metallic and non-metallic materials. Careful 3D-model reconstruction provides the size tolerances up to 0.05 mm for the rough surfaces after stamping and casting operations and up to 0.60 mm for wavy surfaces after 3D-printing by FFF-method. The automatic repairing and healing of the 3D-models can cause artefact building and trespassing the accepted thresholds for tolerances.

International Journal of Computer Science & Engineering Survey, 2012

Various applications of computer graphics, (like animation, scientific visualization, and virtual reality) involve the manipulation of geometric models. They are generally represented by triangular meshes due to its wide acceptance to process on rendering systems. The need of realism and high visual fidelity and the latest advances on scanning devices has increased complexity and size of triangular meshes. The original 3D model gets modified because of activities like approximation, transmission, processing and storage etc. Mostly the modification occurs due to simplification approaches which primarily use geometric distance metric as their simplification criteria. But it is hard to measure a small distance error accurately whereas other geometric or appearance error (like high curvature, thin region, color, texture, normals and volumetric) has greater importance. Hence it is essential to understand the applicability of various parameters to evaluate the quality of 3D model. This paper briefly surveys the various errors analysis techniques, error metrics and tools to assess the quality of 3D mesh models.

International Journal of Space-Based and Situated Computing, 2015

Rapid progresses of 3D depth sensing and 3D printing technologies make digital fabrication an affordable technology for general public on daily life. Both experienced and novice users, who want to design and create new 3D geometric models, can readily acquire 3D object data by capturing their surrounding environments with consumer depth sensors, and produce physical prototypes by using desktop 3D printers. Although 3D modelling is a key technology to bridge a gap between the 3D acquisition with the depth sensors and the 3D printing, there is technically a deep valley preventing the novices from readily practicing the digital fabrication. We designed and developed a system enabling novices to edit the acquired 3D models with a set of simple operations for producing original 3D models. The system supports them to perform all phases, acquiring, modelling, and printing 3D models, through an integrated graphical user interface (GUI). We describe basic principle, architecture, implementation method, and some experiments conducted for verifying the effectiveness of the proposed system.

Computer-Aided Design, 2017

FME Transaction, 2017

This study aims at comparing the accuracy offered by professional and consumer grade 3D printing machines, inside a Fused Deposition Modelling (FDM) process of Additive Manufacturing (AM), in the realisation of complex models. It intends to verify, using an experimentally based approach, how much these two groups of 3D printers differ in terms of achieving complex geometry, surface quality and dimensional stability of additive models. Two consumer grade and professional 3D printers were selected and used for creating a complex model. Limits and benefits provided by each of them in engineering terms were investigated and reported. A religious building was used as a complex model, created by both 3D printers, scanned by reverse engineering technology, then processed by a software package for image processing. In this way, a comparison in models' accuracy was achieved. Results, graphically represented, show some notable differences between 3D printers in terms of accuracy and applicability. They also permit to make recommendations on practical usability of this technology.