2,045 research outputs found

    MeshPipe: a Python-based tool for easy automation and demonstration of geometry processing pipelines

    Get PDF
    The popularization of inexpensive 3D scanning, 3D printing, 3D publishing and AR/VR display technologies have renewed the interest in open-source tools providing the geometry processing algorithms required to clean, repair, enrich, optimize and modify point-based and polygonal-based models. Nowadays, there is a large variety of such open-source tools whose user community includes 3D experts but also 3D enthusiasts and professionals from other disciplines. In this paper we present a Python-based tool that addresses two major caveats of current solutions: the lack of easy-to-use methods for the creation of custom geometry processing pipelines (automation), and the lack of a suitable visual interface for quickly testing, comparing and sharing different pipelines, supporting rapid iterations and providing dynamic feedback to the user (demonstration). From the user's point of view, the tool is a 3D viewer with an integrated Python console from which internal or external Python code can be executed. We provide an easy-to-use but powerful API for element selection and geometry processing. Key algorithms are provided by a high-level C library exposed to the viewer via Python-C bindings. Unlike competing open-source alternatives, our tool has a minimal learning curve and typical pipelines can be written in a few lines of Python code.Peer ReviewedPostprint (published version

    Parametric Deformation of Discrete Geometry for Aerodynamic Shape Design

    Get PDF
    We present a versatile discrete geometry manipulation platform for aerospace vehicle shape optimization. The platform is based on the geometry kernel of an open-source modeling tool called Blender and offers access to four parametric deformation techniques: lattice, cage-based, skeletal, and direct manipulation. Custom deformation methods are implemented as plugins, and the kernel is controlled through a scripting interface. Surface sensitivities are provided to support gradient-based optimization. The platform architecture allows the use of geometry pipelines, where multiple modelers are used in sequence, enabling manipulation difficult or impossible to achieve with a constructive modeler or deformer alone. We implement an intuitive custom deformation method in which a set of surface points serve as the design variables and user-specified constraints are intrinsically satisfied. We test our geometry platform on several design examples using an aerodynamic design framework based on Cartesian grids. We examine inverse airfoil design and shape matching and perform lift-constrained drag minimization on an airfoil with thickness constraints. A transport wing-fuselage integration problem demonstrates the approach in 3D. In a final example, our platform is pipelined with a constructive modeler to parabolically sweep a wingtip while applying a 1-G loading deformation across the wingspan. This work is an important first step towards the larger goal of leveraging the investment of the graphics industry to improve the state-of-the-art in aerospace geometry tools

    Real-time Deformation with Coupled Cages and Skeletons

    Get PDF
    Real-time character deformation is an essential topic in Computer Animation. Deformations can be achieved by using several techniques, but the skeleton-based ones are the most popular. Skeletons allow artists to deform articulated parts of the digital characters by moving their bones. Other techniques, like cage-based ones, are gaining popularity but struggle to be included in animation workflows because they require to change the animation pipeline substantially. This thesis formalizes a technique that allows animators to embed cage-based deformations in standard skeleton-based pipelines. The described skeleton/cage hybrid allows artists to enrich the expressive powers of the skeletons with the degrees of freedom offered by cages. Furthermore, this thesis describes two Graphical User Interfaces dedicated to deformations and animations. The first one, CageLab, allows artists to define cage-based deformations and perform cage editing. The second one, SuperCages GUI, allows artists to author animations and deformations by using the skeleton/cage hybrid described earlier

    A tutorial on motion capture driven character animation

    Get PDF
    Motion capture (MoCap) is an increasingly important technique to create realistic human motion for animation. However MoCap data are noisy, the resulting animation is often inaccurate and unrealistic without elaborate manual processing of the data. In this paper, we will discuss practical issues for MoCap driven character animation, particularly when using commercial toolkits. We highlight open topics in this field for future research. MoCap animations created in this project will be demonstrated at the conference

    SMPLicit: Topology-aware Generative Model for Clothed People

    Get PDF
    In this paper we introduce SMPLicit, a novel generative model to jointly represent body pose, shape and clothing geometry. In contrast to existing learning-based approaches that require training specific models for each type of garment, SMPLicit can represent in a unified manner different garment topologies (e.g. from sleeveless tops to hoodies and to open jackets), while controlling other properties like the garment size or tightness/looseness. We show our model to be applicable to a large variety of garments including T-shirts, hoodies, jackets, shorts, pants, skirts, shoes and even hair. The representation flexibility of SMPLicit builds upon an implicit model conditioned with the SMPL human body parameters and a learnable latent space which is semantically interpretable and aligned with the clothing attributes. The proposed model is fully differentiable, allowing for its use into larger end-to-end trainable systems. In the experimental section, we demonstrate SMPLicit can be readily used for fitting 3D scans and for 3D reconstruction in images of dressed people. In both cases we are able to go beyond state of the art, by retrieving complex garment geometries, handling situations with multiple clothing layers and providing a tool for easy outfit editing. To stimulate further research in this direction, we will make our code and model publicly available at http://www.iri.upc.edu/people/ecorona/smplicit/.Comment: Accepted at CVPR 202
    • …
    corecore