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Now showing 1 - 5 of 5
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    Simulation of Mechanical Weathering for Modeling Rocky Terrains
    (The Eurographics Association, 2024) Mateos, Diego; Carranza, Luis; Susin, Anton; Argudo, Oscar; Marco, Julio; Patow, Gustavo
    Synthetic terrains play a vital role in various applications, including entertainment, training, and simulation. This work focuses on rocky terrains akin to those found in alpine environments, which contain many complex features such as sharp ridges, loose blocks, or overhangs that are often inadequately represented by standard 2D elevation maps. We propose a novel method based on a simplified simulation of mechanical erosion processes commonly observed in high-altitude terrains, in particular the weathering due to freeze-thaw cycles. The ultimate objective is to generate plausible rocky geometry from existing 3D models, as well as account for the temporal evolution due to these weathering processes. Additionally, we have developed an artist-friendly tool integrated as an add-on into Blender.
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    Tree Variations
    (The Eurographics Association, 2017) Argudo, Oscar; Andújar, Carlos; Chica, Antoni; Fco. Javier Melero and Nuria Pelechano
    The cost-effective generation of realistic vegetation is still a challenging topic in computer graphics. The simplest representation of a tree consists of a single texture-mapped billboard. Although a tree billboard does not support top views, this is the most common representation for still image generation in areas such as architecture rendering. In this paper we present a new approach to generate new tree models from a small collection of RGBA images of trees. Key ingredients of our method are the representation of the tree contour space with a small set of basis vectors, the automatic crown/trunk segmentation, and the continuous transfer of RGBA color from the exemplar images to the synthetic target. Our algorithm allows the efficient generation of an arbitrary number of tree variations and thus provides a fast solution to add variety among trees in outdoor scenes.
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    Depth Map Repairing for Building Reconstruction
    (The Eurographics Association, 2018) Andújar, Carlos; Argudo, Oscar; Besora, Isaac; Brunet, Pere; Chica, Antoni; Comino Trinidad, Marc; García-Fernández, Ignacio and Ureña, Carlos
    Structure-from-motion along with multi-view stereo techniques jointly allow for the inexpensive scanning of 3D objects (e.g. buildings) using just a collection of images taken from commodity cameras. Despite major advances in these fields, a major limitation of dense reconstruction algorithms is that correct depth/normal values are not recovered on specular surfaces (e.g. windows) and parts lacking image features (e.g. flat, textureless parts of the facade). Since these reflective properties are inherent to the surface being acquired, images from different viewpoints hardly contribute to solve this problem. In this paper we present a simple method for detecting, classifying and filling non-valid data regions in depth maps produced by dense stereo algorithms. Triangles meshes reconstructed from our repaired depth maps exhibit much higher quality than those produced by state-of-the-art reconstruction algorithms like Screened Poisson-based techniques.
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    CEIG 2025: Frontmatter
    (The Eurographics Association, 2025) Argudo, Oscar; Iparraguirre, Olatz; Argudo, Oscar; Iparraguirre, Olatz
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    Semantic navigation meshes for complex outdoor terrains
    (The Eurographics Association, 2025) Creus, Carles; Argudo, Oscar; Pelechano, Nuria; Argudo, Oscar; Iparraguirre, Olatz
    Traditional navigation meshes are typically based on splitting the terrain into connected convex regions representing walkable cells. This works well for almost flat terrains where obstacles are clearly defined by walls or holes. When applied to complex outdoor environments with many changes in terrain height and slope, traditional approaches fail to correctly identify the walkable areas. Current navigation meshes require the user to specify the character's maximum step size and slope, and then classify the environment as walkable or non-walkable, thus limiting the flexibility to adjust paths to the agents' characteristics. Even if some terrain properties are then computed to add semantics to the navigation mesh, many cells could cover a wide range of values, as this information was ignored during its generation. In this paper, we present a novel approach to generate semantic navigation meshes, where the generated cells have a coherent and low-variance range of values for the chosen semantics (e.g., slope). Cell generation is performed with a semantic partitioning based on a region-growing algorithm. Our navigation mesh allows us to preserve the full complexity of the terrain without forcing a binary decision between walkable and non-walkable and provides useful semantics for the pathfinding algorithm.