Semantic Enrichment for Building Information Modeling: Procedure for Compiling Inference Rules and Operators for Complex Geometry

Semantic enrichment of building models adds meaningful domain-specific or application-specific information to a digital building model. It is applicable to solving interoperability problems and to compilation of models from point cloud data. The SeeBIM (Semantic Enrichment Engine for BIM) prototype software encapsulates domain expert knowledge in computer readable rules for inference of object types, identity and aggregation of systems. However, it is limited to axis-aligned bounding box geometry and the adequacy of its rule-sets cannot be guaranteed. This paper solves these drawbacks by (1) devising a new procedure for compiling inference rule sets that are known a priori to be adequate for complete and thorough classification of model objects, and (2) enhancing the operators to compute complex geometry and enable precise topological rule processing. The procedure for compiling adequate rule sets is illustrated using a synthetic concrete highway bridge model. A real-world highway bridge model, with 333 components of 13 different types and compiled from a laser scanned point cloud, is used to validate the approach and test the enhanced SeeBIM system. All of the elements are classified correctly, demonstrating the efficacy of the approach to semantic enrichment

Blending using ODE swept surfaces with shape control and C1 continuity

Surface blending with tangential continuity is most widely applied in computer aided design, manufacturing systems, and geometric modeling. In this paper, we propose a new blending method to effectively control the shape of blending surfaces, which can also satisfy the blending constraints of tangent continuity exactly. This new blending method is based on the concept of swept surfaces controlled by a vector-valued fourth order ordinary differential equation (ODE). It creates blending surfaces by sweeping a generator along two trimlines and making the generator exactly satisfy the tangential constraints at the trimlines. The shape of blending surfaces is controlled by manipulating the generator with the solution to a vector-valued fourth order ODE. This new blending methods have the following advantages: 1). exact satisfaction of 1C continuous blending boundary constraints, 2). effective shape control of blending surfaces, 3). high computing efficiency due to explicit mathematical representation of blending surfaces, and 4). ability to blend multiple (more than two) primary surfaces

Computing and Visualizing Pose-Interpolating 3D Motions

CAD and animation systems offer a variety of techniques for designing and animating arbitrary movements of rigid bodies. Such tools are essential for planning, analyzing, and demonstrating assembly and disassembly procedures of manufactured products. In this paper, we advocate the use of screw motions for such applications, because of their simplicity, flexibility, uniqueness, and computational advantages. Two arbitrary control-poses of an object are interpolated by a screw motion, which, in general, is unique and combines a minimum-angle rotation around an axis A with a translation by a vector parallel to A. We explain the advantages of screw motions for the intuitive design and local refinement of complex motions. We present a new, simple and efficient algorithm for computing the parameters of a screw motion that interpolates any two control-poses and explain how to use it to produce animations of the moving objects. Finally, we discuss a new and efficient variant of a known procedure for computing a set of faces which may be used to display the 3D region swept by a polyhedron that moves along a screw motion

Animating and Sweeping Polyhedra Along Interpolating Screw Motions

CAD and animation systems offer a variety of techniques for designing and animating arbitrary movements of rigid bodies. Such tools are essential for planning, analyzing, and demonstrating assembly and disassembly procedures of manufactured products. In this paper, we advocate the use of screw motions for such applications, because of their simplicity, flexibility, uniqueness, and computational advantages. Two arbitrary poses of an object are interpolated by a screw motion, which, in general, is unique and combines a minimumangle rotation around an axis A with a translation by a vector parallel to A. We discuss the advantages of screw motions for the intuitive design and local refinement of complex motions. We present a simple and efficient algorithm for computing the parameters of a screw motion that interpolates any two or more poses and explain how to use it to produce animations of the moving objects. Finally, we introduce a geometric construction and propose a simple procedure for..