Browsing by Author "Barbier, Wilhem"

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    Fused Collapsing for Wide BVH Construction
    (The Eurographics Association and John Wiley & Sons Ltd., 2025) Barbier, Wilhem; Paulin, Mathias; Knoll, Aaron; Peters, Christoph
    We propose a novel approach for constructing wide bounding volume hierarchies on the GPU by integrating a simple bottom-up collapsing procedure within an existing binary bottom-up BVH builder. Our approach directly constructs a wide BVH without traversing a temporary binary BVH as done by previous approaches and achieves 1.4−1.6× lower build times. We demonstrate the ability of our algorithm to output compressed wide BVHs using existing compressed representations. We analyze the impact of our method on software raytracing performance and show that it reduces the overall frame time on complex dynamic scenes where rebuilding the BVH every frame is the limiting factor on rendering performance.
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    Lipschitz Pruning: Hierarchical Simplification of Primitive-Based SDFs
    (The Eurographics Association and John Wiley & Sons Ltd., 2025) Barbier, Wilhem; Sanchez, Mathieu; Paris, Axel; Michel, Élie; Lambert, Thibaud; Boubekeur, Tamy; Paulin, Mathias; Thonat, Theo; Bousseau, Adrien; Day, Angela
    Rendering tree-based analytical Signed Distance Fields (SDFs) through sphere tracing often requires to evaluate many primitives per tracing step, for many steps per pixel of the end image. This cost quickly becomes prohibitive as the number of primitives that constitute the SDF grows. In this paper, we alleviate this cost by computing local pruned trees that are equivalent to the full tree within their region of space while being much faster to evaluate. We introduce an efficient hierarchical tree pruning method based on the Lipschitz property of SDFs, which is compatible with hard and smooth CSG operators. We propose a GPU implementation that enables real-time sphere tracing of complex SDFs composed of thousands of primitives with dynamic animation. Our pruning technique provides significant speedups for SDF evaluation in general, which we demonstrate on sphere tracing tasks but could also lead to significant improvement for SDF discretization or polygonization.