• Procedural Cloudscapes at Eurographics 2018

    Procedural Cloudscapes has been accepted at Eurographics.

    We present a phenomenological approach for modeling and animating cloudscapes. We propose a compact procedural model for representing the different types of cloud over a range of altitudes. We define primitive-based field functions that allows the user to control and author the cloud cover over large distances easily. Our approach allows us to animate cloudscapes by morphing: instead of simulating the evolution of clouds using a physically-based simulation, we compute the movement of clouds using key-frame interpolation and tackle the morphing problem as an Optimal Transport problem. The trajectories of the cloud cover primitives are generated by solving an Anisotropic Shortest Path problem with a cost function that takes into account the elevation of the terrain and the characteristics of the wind field.

  • Snow-Covered Landscapes at Eurographics 2018

    Interactive Generation of Time-evolving, Snow-Covered Landscapes with Avalanches has been accepted at Eurographics.

    We introduce a novel method for interactive generation of visually consistent, snow-covered landscapes and provide control of their dynamic evolution over time. Our main contribution is the real-time phenomenological simulation of avalanches and other user-guided events, such as tracks left by Nordic skiing, which can be applied to interactively sculpt the landscape. The terrain is modeled as a height field with additional layers for stable, compacted, unstable, and powdery snow, which behave in combination as a semi-viscous fluid. We incorporate the impact of several phenomena, including sunlight, temperature, prevailing wind direction, and skiing activities. The snow evolution includes snow-melt and snow-drift, which affect stability of the snow mass and the probability of avalanches. A user can shape landscapes and their evolution either with a variety of interactive brushes, or by prescribing events along a winter season time-line. Our optimized GPU-implementation allows interactive updates of snow type and depth across a large terrain, including real-time avalanches, making this suitable for visual assets in computer games. We evaluate our method through perceptual comparison against exiting methods and real snow-depth data.

  • Invited speaker at UBISOFT Procedural Days

    I will make a presentation on procedural modeling and generation at UBISOFT Paris: Authoring Landscapes by Combining Ecosystem and Terrain Erosion Simulation.

    In this presentation, I will introduce a novel framework for interactive landscape authoring that supports bi-directional feedback between erosion and vegetation simulation. Vegetation and terrain erosion have strong mutual impact and their interplay influences the overall realism of virtual scenes. I will show how to simulate the effect of a variety of geomorphological agents and the mutual interaction between different material and vegetation layers, including rock, sand, humus, grass, shrubs, and trees.

  • Deep Terrains at SIGGRAPH ASIA

    Interactive Example-Based Terrain Authoring with Conditional Generative Adversarial Networks has been accepted at SIGGRAPH ASIA.

    Watch Terrain Generation With Deep Learning | Two Minute Papers #208

    Authoring virtual terrains presents a challenge and there is a strong need for authoring tools able to create realistic terrains with simple user-inputs and with high user control. We propose an example-based authoring pipeline that uses a set of terrain synthesizers dedicated to specific tasks. Each terrain synthesizer is a Conditional Generative Adversarial Network trained by using real-world terrains and their sketched counterparts. The training sets are built automatically with a view that the terrain synthesizers learn the generation from features that are easy to sketch. During the authoring process, the artist first creates a rough sketch of the main terrain features, such as rivers, valleys and ridges, and the algorithm automatically synthesizes a terrain corresponding to the sketch using the learned features of the training samples. Our framework allows for an easy terrain authoring and provides a high level of realism for a minimum sketch cost. We show various examples of terrain synthesis created by experienced as well as inexperienced users who are able to design complex and diverse terrains in a very short time.

  • Full Professor Position at Université Lyon 1

    I moved to Université Lyon 1 where I hold a full professor position in the computer science department.

    I will be teaching Master classes in computer graphics, and undergraduate courses in object oriented programming and algorithmics.

  • GEOMOD at SIGGRAPH

    Our paper Authoring Landscapes by Combining Ecosystem and Terrain Erosion Simulation has been accepted at SIGGRAPH.

    We introduce a novel framework for interactive landscape authoring that supports bi-directional feedback between erosion and vegetation simulation. Vegetation and terrain erosion have strong mutual impact and their interplay influences the overall realism of virtual scenes. Despite their importance, these complex interactions have been neglected in computer graphics. Our framework overcomes this by simulating the effect of a variety of geomorphological agents and the mutual interaction between different material and vegetation layers, including rock, sand, humus, grass, shrubs, and trees. Users are able to exploit these interactions with an authoring interface that consistently shapes the terrain and populates it with details.

  • Eurographics 2017 in Lyon

    The GeoMod team had the pleasure to organize and welcome the prestigious conference Eurographics 2017 April 24th-28th in Lyon's Convention Center. This event was a clear success as we received more than 400 researchers and industrials for 79 hours of scientific presentations around various computer graphics topics: geometry and modeling, image and video processing, rendering, simulation, 3D printing. The symbiosis between academic and industrial research culminated during four plenary sessions, making us discover computational photography (Frédo Durand, MIT), the joy of computer graphics programming (Bruno Lévy, INRIA), the secrets of Hollywood movies (Parolo Emilio Selva, Weta Digital) and the mysteries of time (Jos Stam, Autodesk). LIRIS thanks the local organizing team led by Eric Galin and applauds the success of Eurographics 2017!

  • CGI Paper: Landscapes

    Our paper Coherent Multi-Layer Landscape Synthesis has been accepted at CGI.

    We present an effcient method for generating coherent multi-layer landscapes. We use a dictionary built from exemplars to synthesize high-resolution fully-featured terrains from input low-resolution elevation data. Our example-based method consists in analyzing real world terrain examples and learning the procedural rules directly from these inputs. We take into account not only the elevation of the terrain, but also additional layers such as the slope, orientation, drainage area, the density and distribution of vegetation, and the soil type. By increasing the variety of terrain exemplars, our method allows the user to synthesize and control different types of landscapes and biomes, such as temperate or rain forests, arid deserts and mountains.

  • IEEE Transactions on Visualization and Computer Graphics

    Our paper Sculpting Mountains: Interactive Terrain Modeling Based on Subsurface Geology has been accepted at IEEE TVCG.

    Most mountain ranges are formed by the compression and folding of colliding tectonic plates. Subduction of one plate causes large-scale asymmetry while their layered composition (or stratigraphy) explains the multi-scale folded strata observed on real terrains. We introduce a novel interactive modeling technique to generate visually plausible, large scale terrains that capture these phenomena. Our method draws on both geological knowledge for consistency and on sculpting systems for user interaction. The user is provided hands-on control on the shape and motion of tectonic plates, represented using a new geologically-inspired model for the Earth crust. The model captures their volume preserving and complex folding behaviors under collision, causing mountains to grow. It generates a volumetric uplift map representing the growth rate of subsurface layers. Erosion and uplift movement are jointly simulated to generate the terrain. The stratigraphy allows us to render folded strata on eroded cliffs. We validated the usability of our sculpting interface through a user study, and compare the visual consistency of the earth crust model with geological simulation results and real terrains.

  • Multi-layered Terrain Synthesis

    Our paper Coherent multi-layer landscape Synthesis has been accepted at CGI and will be published in The Visual Computer.

    We present an efficient method for generating coherent multi-layer landscapes. We use a dictionary built from exemplars to synthesize high-resolution fully-featured terrains from input low-resolution elevation data. Our example-based method consists in analyzing real world terrain examples and learning the procedural rules directly from these inputs. We take into account not only the elevation of the terrain, but also additional layers such as the slope, orientation, drainage area, the density and distribution of vegetation, and the soil type. By increasing the variety of terrain exemplars, our method allows the user to synthesize and control different types of landscapes and biomes, such as temperate or rain forests, arid deserts and mountains.