Computing the directed Hausdorff distance between two triangle meshes is a fundamental operation in geometry processing and simulation. While existing certified branch-and-bound (B&B) methods are efficient for well-separated geometry, they can become prohibitively expensive on large models under tight tolerances and near-zero distance configurations where pruning is limited. We present a GPU-accelerated certified B&B algorithm that explicitly maintains enclosing lower and upper bounds on the directed Hausdorff distance and terminates once their normalized gap, measured with respect to the bounding-box diagonal of the source mesh, meets a user-prescribed tolerance. To map the inherently prioritized search to SIMT (single-instruction, multiple-thread) hardware, we replace priority queues and recursion with a sorted, double-buffered wavefront pipeline built from bulk-parallel worklists for bound evaluation, culling, subdivision, and compaction. To mitigate loose bounds on thin primitives while preserving predictable stream behavior, we introduce a fixed-cardinality adaptive subdivision scheme that selectively applies double longest-edge bisection. To remain robust in deep-refinement regimes, we add a resource-aware deferral mechanism that enforces a device-capacity invariant by prioritizing candidates likely to be culled while postponing expensive ones. Finally, we improve numerical robustness under FP32 (single precision) via triangle-local coordinate transforms and other conservative numerical safeguards, and enhance coherence by spatially ordering the active set and traversing the BVH (bounding volume hierarchy) in triangle packets. Under the same stopping tolerance, experiments on an NVIDIA RTX 5090 show that our GPU solver remains numerically consistent with the FP64 CPU baseline, with normalized cross-platform deviation below 0.01% in over 99.9% of cases. Our method achieves millisecond-scale runtimes capable of supporting interactive frame rates, even on models with millions of triangles. Across the comparison set, it delivers throughput speedups of 836× on the Thingi10K/TetWild benchmark ( A → B ) and 709× on the Thingi10K/Decimation benchmark. Code and data for this paper are available at https://github.com/fhp-transient/gpu-hausdorff.

Lattice structures, distinguished by their customizable geometries at the microscale and outstanding mechanical performance, have found widespread application across various industries. One fundamental process in their design and manufacturing is constructing boundary representation (B-rep) models, which are essential for running advanced applications like simulation, optimization, and process planning. However, this construction process presents significant challenges due to the high complexity of lattice structures, particularly in generating nodal shapes where robustness and smoothness issues can arise from the complex intersections between struts. To address these challenges, this paper proposes a novel approach for lattice structure construction by cutting struts and filling void regions with subdivisional nodal shapes. Inspired by soap films, the method generates smooth, shape-preserving control meshes using Laplacian fairing and subdivides them through the point-normal Loop (PN-Loop) subdivision scheme to obtain subdivisional nodal shapes. The proposed method ensures robust model construction with reduced shape deviations, enhanced surface fairness, and smooth transitions between subdivisional nodal shapes and retained struts. The effectiveness of the method has been demonstrated by a series of examples and comparisons. The code and associated data have been made available at: https://github.com/Qiang-Zou/Subdiv-Lattice .

Generative methods for creating computer-aided design (CAD) models have gained significant attention over the past two years. However, existing methods lack fine-grained control over the generated CAD models, making it difficult to manage details such as model dimensions and the relative structure of components. To address these limitations, this study introduces Diffusion-CAD, a diffusion-based generative approach that outputs CAD construction sequences. Diffusion-CAD iteratively denoises Gaussian noise into continuous CAD vectors, which are then transformed into discrete CAD sequences. We designed classifier-free and classifier-guided methods to control the distribution of Gaussian noise, CAD sequences, and noisy CAD vectors separately, thereby achieving a variety of fine-grained control tasks. Extensive experiments demonstrated the superior performance and novel capabilities of the proposed method for conditional generation tasks.

Integrating modern artificial intelligence (AI) techniques, particularly generative AI, holds the promise of revolutionizing computer-aided design (CAD) tools and the engineering design process. However, the direction of “AI+CAD” remains unclear: how will the current generation of intelligent CAD (ICAD) differ from its predecessor in the 1980s and 1990s, what strategic pathways should researchers and engineers pursue for its implementation, and what potential technical challenges might arise?As an attempt to address these questions, this paper investigates the transformative role of modern AI techniques in advancing CAD towards ICAD. It first analyzes the design process and reconsiders the roles AI techniques can assume in this process, highlighting how they can restructure the path humans, computers, and designs interact with each other. The primary conclusion is that ICAD systems should assume an intensional rather than an extensional role in the design process. This offers insights into the evaluation of the previous generation of ICAD (ICAD 1.0) and outlines a prospective framework and trajectory for the next generation of ICAD (ICAD 2.0).