Feature-based terrain editing from complex sketches

Abstract

International audienceWe present a new method for first person sketch-based editing of terrain models. As in usual artistic pictures, the input sketchdepicts complex silhouettes with cusps and T-junctions, which typically correspond to non-planar curves in 3D. After analysingdepth constraints in the sketch based on perceptual cues, our method best matches the sketched silhouettes with silhouettes or ridgesof the input terrain. A deformation algorithm is then applied to the terrain, enabling it to exactly match the sketch from the givenperspective view, while insuring that none of the user-defined silhouettes is hidden by another part of the terrain. We extend thissketch-based terrain editing framework to handle a collection of multi-view sketches. As our results show, this method enablesusers to easily personalize an existing terrain, while preserving its plausibility and style

A Review of Digital Terrain Modeling

“…Tasse et al . [TEC∗14] start from a similar initial premise in that they match first‐person silhouettes using existing sample data (Figure ), but in their system silhouettes can be in a much more complex arrangement, with internal silhouettes and t‐junctions representing occlusions. The method is fully automated and deforms the source terrain rather than applying cuts and joins, which leads to more plausible results.…”

“…Altering existing terrains: a terrain edited from a first person viewpoint using silhouette sketching (from [TEC∗14]).…”

“…This is why attempts to minimize distortion, such as used in Tasse et al . [TEC∗14], are so necessary.…”

Surfacing curve networks with normal control

“…More generally, surfacing 3D networks is a fundamental problem in geometric modeling. Apart from traditional CAD modeling [15,8,16,9], sketch-based interfaces [17,18,19] and sketch-based modeling techniques [20,21,22,23,24,25] have recently become increasingly popular in a range of versatile application areas. Even though normal vectors are not part of a typical sketch-based modeler output [26,17,18], recent state of the art [24] in surfacing 3D curve networks however requires estimation of normal vectors along the curve network.…”

Foreword to Special Section on Graphics Interaction

“…Finally, Tasse et al [10] present a new method for first person sketch-based editing of terrain models. They order strokes with respect to their distance from the camera in multi-view perspective sketches, and from these sketched silhouettes they match terrain features and apply deformations to the terrain.…”