277 research outputs found
Large Scale Terrain Generation from Tectonic Uplift and Fluvial Erosion
International audienceAt large scale, landscapes result from the combination of two major processes: tectonics which generate the main relief through crust uplift, and weather which accounts for erosion. This paper presents the first method in computer graphics that combines uplift and hydraulic erosion to generate visually plausible terrains. Given a user-painted uplift map, we generate a stream graph over the entire domain embedding elevation information and stream flow. Our approach relies on the stream power equation introduced in geology for hydraulic erosion. By combining crust uplift and stream power erosion we generate large realistic terrains at a low computational cost. Finally, we convert this graph into a digital elevation model by blending landform feature kernels whose parameters are derived from the information in the graph. Our method gives high-level control over the large scale dendritic structures of the resulting river networks, watersheds, and mountains ridges
Automatic evolution of programs for procedural generation of terrains for video games: accessibility and edge length constraints
Nowadays the video game industry is facing
a big challenge: keep costs under control as games become
bigger and more complex. Creation of game content,
such as character models, maps, levels, textures,
sound effects and so on, represent a big slice of total
game production cost. Hence, the video game industry
is increasingly turning to procedural content generation
to amplify the cost-effectiveness of the efforts of video
game designers. However, procedural methods for automated
content generation are difficult to create and
parametrize. In this work we study a Genetic Programming
based procedural content technique to generate
procedural terrains that do not require parametrization,
thus, allowing to save time and help reducing production
costs. Generated procedural terrains present aesthetic
appeal; however, unlike most techniques involving
aesthetic, our approach does not require a human to
perform the evaluation. Instead, the search is guided by
the weighted sum of two morphological metrics: terrain
accessibility and obstacle edge length. The combination of the two metrics allowed us to find a wide range of fit
terrains that present more scattered obstacles in different
locations, than our previous approach with a single
metric. Procedural terrains produced by this technique are already in use in a real video game
Distributed texture-based terrain synthesis
Terrain synthesis is an important field of Computer Graphics that deals with the generation of 3D landscape models for use in virtual environments. The field has evolved to a stage where large and even infinite landscapes can be generated in realtime. However, user control of the generation process is still minimal, as well as the creation of virtual landscapes that mimic real terrain. This thesis investigates the use of texture synthesis techniques on real landscapes to improve realism and the use of sketch-based interfaces to enable intuitive user control
First Person Sketch-based Terrain Editing
International audienceWe present a new method for first person sketch-based editing of terrain models. As in usual artistic pictures, the input sketch depicts complex silhouettes with cusps and T-junctions, which typically correspond to non-planar curves in 3D. After analysing depth constraints in the sketch based on perceptual cues, our method best matches the sketched silhouettes with silhouettes or ridges of the input terrain. A specific deformation algorithm is then applied to the terrain, enabling it to exactly match the sketch from the given perspective view, while insuring that none of the user-defined silhouettes is hidden by another part of the terrain. As our results show, this method enables users to easily personalize an existing terrain, while preserving its plausibility and style
Procedural modelling of terrains with constraints
Terrain is an essential part of any outdoor environment and, consequently, many techniques
have appeared that deal with the problem of its automatic generation, such as procedural
modeling. One form to create terrains is using noise functions because its low computational cost and its random result. However, the randomness of these functions also makes it
difficult to have any control over the result obtained. In order to solve the problem of lack
of control, this paper presents a new method noise-based that allows procedural terrains creation with elevation constraints (GPS routes, points of interest and areas of interest). For
this, the method establishes the restrictions as fixed values in the heightmap function and
creates a system of equations to obtain all points that they depend this restrictions. In this
way, the terrain obtained maintains the random noise, but including the desired restrictions.
The paper also includes how we apply this method on large terrain models without losing resolution or increasing the computational cost excessively. The results show that our
method makes it possible to integrate this kind of constraints with high accuracy and realism
while preserving the natural appearance of the procedural generation
Erosion, Self-Organization, and Procedural Modeling
Procedural modeling of natural objects such as coastlines and terrains in combination with their characteristic erosion features involves integration of appropriate physical models with the procedural approach and culminates in the development of physically-based simulations. I have invented a modeling paradigm for designing this type of simulations in a way that generalizes formation of complex relationships between erosion features, such as the tributary relationship. My generalization uses self-organization to define where erosion occurs and how it propagates rather than emphasizing the exact mechanism of erosion and the details of what happens during each erosion event. Propagation of state changes due to self-organization can also lead to emergence of fractal character, which is essential for modeling of natural objects, without explicit fractal synthesis. I successfully apply my methodology to procedural modeling of dunes, coastlines, terrains that undergo hydraulic erosion due to channel networks, and 3D channel networks that form underground
Genetic terrain programming: an aesthetic approach to terrain generation
Comunicação apresentada na conferência Computer Games and Allied Technology, 8, Singapore, 2008.Nowadays there are a wide range of techniques for terrain generation, but are focused on
providing realistic terrains often neglecting the aesthetic appeal. The Genetic Terrain
Programming technique, based on evolutionary design with Genetic Programming, allows
designers to evolve terrains according to their aesthetic feelings or desired features. This
technique evolves TPs (Terrain Programmes) that are capable of generating different terrains, but
consistently with the same features. This paper presents a study about the perseverance of
terrain features of the TPs across different LODs (Levels Of Detail). Results showed it is possible
to use low LODs during the evolutionary phase without compromising results and the terrain
features generated by a TPs are scale invariant
Feature-rich distance-based terrain synthesis
This thesis describes a novel terrain synthesis method based on distances in a weighted graph. The method begins with a regular lattice with arbitrary edge weights; heights are determined by path cost from a set of generator nodes. The shapes of individual terrain features, such as mountains, hills, and craters, are specified by a monotonically decreasing profile describing the cross-sectional shape of a feature, while the locations of features in the terrain are specified by placing the generators. Pathing places ridges whose initial location have a dendritic shape. The method is robust and easy to control, making it possible to create pareidolia effects. It can produce a wide range of realistic synthetic terrains such as mountain ranges, craters, faults, cinder cones, and hills. The algorithm incorporates random graph edge weights, permits the inclusion of multiple topography profiles, and allows precise control over placement of terrain features and their heights. These properties all allow the artist to create highly heterogeneous terrains that compare quite favorably to existing methods
Feature-based terrain editing from complex sketches
We present a new method for first person sketch-based editing of terrain models. As in usual artistic pictures, the input sketch
depicts complex silhouettes with cusps and T-junctions, which typically correspond to non-planar curves in 3D. After analysing
depth constraints in the sketch based on perceptual cues, our method best matches the sketched silhouettes with silhouettes or ridges
of the input terrain. A deformation algorithm is then applied to the terrain, enabling it to exactly match the sketch from the given
perspective view, while insuring that none of the user-defined silhouettes is hidden by another part of the terrain. We extend this
sketch-based terrain editing framework to handle a collection of multi-view sketches. As our results show, this method enables
users to easily personalize an existing terrain, while preserving its plausibility and style.This work was conducted during an internship of Flora Ponjou Tasse at Inria Rhône-Alpes in Grenoble. It was partly supported by the ERC advanced grant EXPRESSIVE.This is the accepted manuscript. The final version is available from Elsevier at http://www.sciencedirect.com/science/article/pii/S009784931400081
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