Embedded Implicit Stand-ins for Animated Meshes: a Case of Hybrid Modelling

In this paper we address shape modelling problems, encountered in computer animation and computer games development that are difficult to solve just using polygonal meshes. Our approach is based on a hybrid modelling concept that combines polygonal meshes with implicit surfaces. A hybrid model consists of an animated polygonal mesh and an approximation of this mesh by a convolution surface stand-in that is embedded within it or is attached to it. The motions of both objects are synchronised using a rigging skeleton. This approach is used to model the interaction between an animated mesh object and a viscoelastic substance, normally modelled in implicit form. The adhesive behaviour of the viscous object is modelled using geometric blending operations on the corresponding implicit surfaces. Another application of this approach is the creation of metamorphosing implicit surface parts that are attached to an animated mesh. A prototype implementation of the proposed approach and several examples of modelling and animation with near real-time preview times are presented

3D Character Modeling in Virtual Reality

The paper presents a virtual reality modeling system based on interactive web technologies. The system's goal is to provide a user-friendly virtual environment for the development of 3D characters with an articulated structure. The interface allows the modeling of both the character's joint structure (the hierarchy) and its segment geometry (the skin). The novelty of the system consists of (1) the combination of web technologies used (VRML, Java and EAI) which provides the possibility of online modeling, (2) rules and constraints based operations and thus interface elements, (3) vertices and sets of vertices used as graphics primitives and (4) the possibility to handle and extend hierarchies based on the H-anim structure elements

Shape: A 3D Modeling Tool for Astrophysics

We present a flexible interactive 3D morpho-kinematical modeling application for astrophysics. Compared to other systems, our application reduces the restrictions on the physical assumptions, data type and amount that is required for a reconstruction of an object's morphology. It is one of the first publicly available tools to apply interactive graphics to astrophysical modeling. The tool allows astrophysicists to provide a-priori knowledge about the object by interactively defining 3D structural elements. By direct comparison of model prediction with observational data, model parameters can then be automatically optimized to fit the observation. The tool has already been successfully used in a number of astrophysical research projects.Comment: 13 pages, 11 figures, accepted for publication in the "IEEE Transactions on Visualization and Computer Graphics

Developing Guidelines for Two-Dimensional Model Review and Acceptance

Two independent modelers ran two hydraulic models, SRH-2D and HEC-RAS 2D. The models were applied to the Lakina River (MP 44 McCarthy Road) and to Quartz Creek (MP 0.7 Quartz Creek Road), which approximately represent straight and bend flow conditions, respectively. We compared the results, including water depth, depth averaged velocity, and bed shear stress, from the two models for both modelers. We found that the extent and density of survey data were insufficient for Quartz Creek. Neither model was calibrated due to the lack of basic field data (i.e., discharge, water surface elevation, and sediment characteristics). Consequently, we were unable to draw any conclusion about the accuracy of the models. Concerning the time step and the equations used (simplified or full) to solve the momentum equation in the HEC-RAS 2D model, we found that the minimum time step allowed by the model must be used if the diffusion wave equation is used in the simulations. A greater time step can be used if the full momentum equation is used in the simulations. We developed a set of guidelines for reviewing model results, and developed and provided a two-day training workshop on the two models for ADOT&PF hydraulic engineers

3D Modeling to Reconstruct a Paleontological Site: Museum of Casal de’ Pazzi in Rome

Today, 3D modeling allows the creation of sophisticated reconstructions in the field of Paleontology that until a short time ago could only be obtained with traditional techniques and hand-made drawings. An interesting methodological application is the Museum of Casal de’ Pazzi in Rome. In this case 3D modeling has allowed the reconstruction, starting from the discovery of some finds, an “Ancient Elephant,” a “Urus,” and a “Neanderthal Man”. Modeling was performed with the help of scientific data and experienced paleontologists and anthropologists. 3D models were completed with the “digital sculpting” technique, allowing a more accurate reconstruction of the shape and appearance of the animals and hominin. The models were subsequently used for multimedia and interactive communication, describing the history of the place where the Museum is located

COMPUTER AIDED DESIGN IN URBAN ARHITECTURE 3D MODELING

The gap from the PC made sketches with the help of the china ink pen and ruler to the digitised drawing boards, high diagonal monitors and 3D projecting is truly spectacular. The increasingly efficient and more specialized programs allow the architects a whole range of facilities providing drawing commands and changes very easy to use, automatic rating, operating simultaneously in multiple windows, building sections and extracts of the plan, 3D views design and even projecting in virtual reality. Applications made to date using virtual reality technologies are characterized, essentially, by generating artificial world and immerging the user into this world. Evolution and effectiveness of such systems are conditioned, first, by the increased hardware performance (computers and specialized devices for interaction) so as to ensure a full immersion of man in the virtual world and, implicitly, a real-time communication with him.Computer aided design, Architecture, C# interface, urban 3D modeling, urban design. Journal: Theoretical and Empirical Researches in Urban Management

Volumetric kombat:a case study on developing a VR game with Volumetric Video

This paper presents a case study on the development of a Virtual Reality (VR) game using Volumetric Video (VV) for character animation. We delve into the potential of VV, a technology that fuses video and depth sensor data, which has progressively matured since its initial introduction in 1995. Despite its potential to deliver unmatched realism and dynamic 4D sequences, VV applications are predominantly used in non-interactive scenarios. We explore the barriers to entry such as high costs associated with large-scale VV capture systems and the lack of tools optimized for VV in modern game engines. By actively using VV to develop a VR game, we examine and overcome these constraints developing a set of tools that address these challenges. Drawing lessons from past games, we propose an open-source data processing workflow for future VV games. This case study provides insights into the opportunities and challenges of VV in game development and contributes towards making VV more accessible for creators and researchers

From early draping to haute couture models: 20 years of research

Simulating the complex fashion garments of haute couture can only be reached through an optimal combination of modeling techniques and numerical methods that combines high computation efficiency with the versatility required for simulating intricate garment designs. Here we describe optimal choices illustrated by their integration into a design and simulation tool that allow interactive prototyping of garments along drape motion and comfortability tests on animated postures. These techniques have been successfully used to bring haute couture garments from early draping of fashion designers, to be simulated and visualized in the virtual worl