https://perso.liris.cnrs.fr/apeytavi/website/categories/implicit-surfaces/ Recent content in Implicit surfaces on Adrien Peytavie Hugo -- gohugo.io en-us Thu, 01 Jan 2026 00:00:00 +0000 https://perso.liris.cnrs.fr/apeytavi/website/research/terrains/ Mon, 01 Jan 0001 00:00:00 +0000 https://perso.liris.cnrs.fr/apeytavi/website/research/terrains/ Synthesising terrains that hold together from the shape of a single valley up to an entire planet, and that a designer can still steer. The methods combine erosion and tectonic models, which give landforms their geological plausibility, with sparse authoring primitives, sketches and example-based synthesis, which give back the control a pure simulation takes away. https://perso.liris.cnrs.fr/apeytavi/website/research/virtual-worlds/ Mon, 01 Jan 0001 00:00:00 +0000 https://perso.liris.cnrs.fr/apeytavi/website/research/virtual-worlds/ Representation, level of detail and interactive rendering of environments too large to be held in memory, bringing terrain, vegetation and built elements together in a single scene. Scale is the constraint that shapes everything else here, since a representation that does not degrade gracefully cannot be explored in real time. https://perso.liris.cnrs.fr/apeytavi/website/publication/hal-05713515/ Thu, 01 Jan 2026 00:00:00 +0000 https://perso.liris.cnrs.fr/apeytavi/website/publication/hal-05713515/ We introduce the PhaseTree, a novel hierarchical construction-tree representation for compactly modeling volumetric objects composed of multiple phases or materials across scales. An object is defined as a single construction tree that combines phase-aware primitives through composition and warping operators, yielding a unified multiphase signed distance representation that naturally supports complex topologies and interfaces between phases. https://perso.liris.cnrs.fr/apeytavi/website/publication/hal-05308455/ Wed, 01 Jan 2025 00:00:00 +0000 https://perso.liris.cnrs.fr/apeytavi/website/publication/hal-05308455/ Processing and particularly visualizing implicit surfaces remains computationally intensive when dealing with complex objects built from construction trees. We introduce optimization nodes to reduce the computational cost of the field function evaluation for hierarchical construction trees, while preserving the Lipschitz or conservative properties of the function. https://perso.liris.cnrs.fr/apeytavi/website/publication/hal-03331697/ Fri, 01 Jan 2021 00:00:00 +0000 https://perso.liris.cnrs.fr/apeytavi/website/publication/hal-03331697/ We present a geologically-based method to generate complex karstic networks. Karsts are a type of landscape formed by the dissolution of highly soluble rocks (generally limestones). In particular, they are characterized by complex underground networks made of varieties of tunnels and breakout chambers with stalagmites and stalactites. https://perso.liris.cnrs.fr/apeytavi/website/publication/hal-03952188/ Fri, 01 Jan 2021 00:00:00 +0000 https://perso.liris.cnrs.fr/apeytavi/website/publication/hal-03952188/ We present a geologically-based method to generate complex karstic networks. Karsts are a type of landscape formed bythe dissolution of highly soluble rocks (generally limestones). In particular, they are characterized by complex undergroundnetworks made of varieties of tunnels and breakout chambers with stalagmites and stalactites. Our method computes skeletons ofkarstic networks by using a gridless anisotropic shortest path algorithm according to field data of the underground system (suchas inlets and outlets), geomorphological features and parameters such as faults, inception horizons, fractures, and permeabilitycontrasts. https://perso.liris.cnrs.fr/apeytavi/website/publication/hal-02926218/ Wed, 01 Jan 2020 00:00:00 +0000 https://perso.liris.cnrs.fr/apeytavi/website/publication/hal-02926218/ We present a novel geologically-based method to generate vertical walls of rocky cliffs, crags or promontories. Our method procedurally generates a distribution of fractures in the bedrock to create a set of tiling blocks defined as implicit volumetric primitives. Blocks are in turn implicitly replicated over the vertical parts of the terrain and combined together to obtain a consistent volumetric representation of the fractured bedrock patterns using generalized union and blending operators. https://perso.liris.cnrs.fr/apeytavi/website/publication/hal-04360946/ Wed, 01 Jan 2020 00:00:00 +0000 https://perso.liris.cnrs.fr/apeytavi/website/publication/hal-04360946/ We present a novel geologically-based method to generate vertical walls of rocky cliffs, crags or promontories. Our method procedurally generates a distribution of fractures in the bedrock to create a set of tiling blocks defined as implicit volumetric primitives. Blocks are in turn implicitly replicated over the vertical parts of the terrain and combined together to obtain a consistent volumetric representation of the fractured bedrock patterns using generalized union and blending operators. https://perso.liris.cnrs.fr/apeytavi/website/publication/hal-02507361/ Wed, 01 Jan 2020 00:00:00 +0000 https://perso.liris.cnrs.fr/apeytavi/website/publication/hal-02507361/ We introduce Segment Tracing, a new algorithm that accelerates the classical Sphere Tracing method for computing the intersection between a ray and an implicit surface. Our approach consists in computing the Lipschitz bound locally over a segment to improve the marching step computation and accelerate the overall process. https://perso.liris.cnrs.fr/apeytavi/website/publication/hal-02273097/ Tue, 01 Jan 2019 00:00:00 +0000 https://perso.liris.cnrs.fr/apeytavi/website/publication/hal-02273097/ While three-dimensional landforms, such as arches and overhangs, occupy a relatively small proportion of most computer generated landscapes, they are distinctive and dramatic and have an outsize visual impact. Unfortunately, the dominant heightfield representation of terrain precludes such features, and existing in-memory volumetric structures are too memory intensive to handle larger scenes. https://perso.liris.cnrs.fr/apeytavi/website/publication/hal-03184694/ Mon, 01 Jan 2018 00:00:00 +0000 https://perso.liris.cnrs.fr/apeytavi/website/publication/hal-03184694/ While three-dimensional landforms, such as arches and overhangs, occupy a relatively small proportion of most computer-generated landscapes, they are distinctive and dramatic and have an outsize visual impact. Unfortunately, the dominant heightfield representation of terrain precludes such features, and existing in-memory volumetric structures are too memory intensive to handle larger scenes. https://perso.liris.cnrs.fr/apeytavi/website/publication/hal-00463263/ Thu, 01 Jan 2009 00:00:00 +0000 https://perso.liris.cnrs.fr/apeytavi/website/publication/hal-00463263/ In this paper, we present a framework for representing complex terrains with such features as overhangs, arches and caves and including different materials such as sand and rocks. Our hybrid model combines a volumetric discrete data structure that stores the different materials and an implicit representation for sculpting and reconstructing the surface of the terrain. https://perso.liris.cnrs.fr/apeytavi/website/publication/hal-01531263/ Tue, 01 Jan 2008 00:00:00 +0000 https://perso.liris.cnrs.fr/apeytavi/website/publication/hal-01531263/ Nous proposons un modèle hybride combinant une représentation discrète et une représentation implicite permettant de synthétiser des terrains complexes de topologie et de géométrie quelconque. Notre approche permet de représenter des surplombs, des grottes, des arches ainsi que les détails du sol tel que les pierres, la terre ou le sable.