Browsing by Author "Peytavie, Adrien"

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    Authoring Terrains with Spatialised Style
    (The Eurographics Association and John Wiley & Sons Ltd., 2023) Perche, Simon; Peytavie, Adrien; Benes, Bedrich; Galin, Eric; Guérin, Eric; Chaine, Raphaëlle; Deng, Zhigang; Kim, Min H.
    Various terrain modelling methods have been proposed for the past decades, providing efficient and often interactive authoring tools. However, they seldom include any notion of style, which is critical for designers in the entertainment industry. We introduce a new generative network method that bridges the gap between automatic terrain synthesis and authoring, providing a versatile set of authoring tools allowing spatialised style. We build upon the StyleGAN2 architecture and extend it with authoring tools. Given an input sketch or existing elevation map, our method generates a terrain with features that can be authored, enhanced, and augmented using interactive brushes and style manipulation tools. The strength of our approach lies in the versatility and interoperability of the different tools. We validate our method quantitatively with drainage calculation against other previous techniques and qualitatively by asking users to follow a prompt or freely create a terrain.
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    Desertscapes Simulation
    (The Eurographics Association and John Wiley & Sons Ltd., 2019) Paris, Axel; Peytavie, Adrien; Guérin, Eric; Argudo, Oscar; Galin, Eric; Lee, Jehee and Theobalt, Christian and Wetzstein, Gordon
    We present an interactive aeolian simulation to author hot desert scenery. Wind is an important erosion agent in deserts which, despite its importance, has been neglected in computer graphics. Our framework overcomes this and allows generating a variety of sand dunes, including barchans, longitudinal and anchored dunes, and simulates abrasion which erodes bedrock and sculpts complex landforms. Given an input time varying high altitude wind field, we compute the wind field at the surface of the terrain according to the relief, and simulate the transport of sand blown by the wind. The user can interactively model complex desert landscapes, and control their evolution throughout time either by using a variety of interactive brushes or by prescribing events along a user-defined time-line.
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    Interactive Authoring of Terrain using Diffusion Models
    (The Eurographics Association and John Wiley & Sons Ltd., 2023) Lochner, Joshua; Gain, James; Perche, Simon; Peytavie, Adrien; Galin, Eric; Guérin, Eric; Chaine, Raphaëlle; Deng, Zhigang; Kim, Min H.
    Generating heightfield terrains is a necessary precursor to the depiction of computer-generated natural scenes in a variety of applications. Authoring such terrains is made challenging by the need for interactive feedback, effective user control, and perceptually realistic output encompassing a range of landforms.We address these challenges by developing a terrain-authoring framework underpinned by an adaptation of diffusion models for conditional image synthesis, trained on real-world elevation data. This framework supports automated cleaning of the training set; authoring control through style selection and feature sketches; the ability to import and freely edit pre-existing terrains, and resolution amplification up to the limits of the source data. Our framework improves on previous machine-learning approaches by: expanding landform variety beyond mountainous terrain to encompass cliffs, canyons, and plains; providing a better balance between terseness and specificity in user control, and improving the fidelity of global terrain structure and perceptual realism. This is demonstrated through drainage simulations and a user study testing the perceived realism for different classes of terrain. The full source code, blender add-on, and pretrained models are available.
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    Synthesizing Geologically Coherent Cave Networks
    (The Eurographics Association and John Wiley & Sons Ltd., 2021) Paris, Axel; Guérin, Eric; Peytavie, Adrien; Collon, Pauline; Galin, Eric; Zhang, Fang-Lue and Eisemann, Elmar and Singh, Karan
    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. Our method computes skeletons of karstic networks by using a gridless anisotropic shortest path algorithm according to field data of the underground system (such as inlets and outlets), geomorphological features and parameters such as faults, inception horizons, fractures, and permeability contrasts. From this skeleton, we define the geometry of the conduits as a signed distance function construction tree combining primitives with blending and warping operators. Our framework provides multiple levels of control, allowing us to author both the structure of the karstic network and the geometric cross-section shapes and details of the generated conduits.