B. Wyvill | University of Victoria (original) (raw)

Papers by B. Wyvill

Research paper thumbnail of Eastern Perspectives and the Question of Personal Expression

Methods in non-photorealistic graphics have tended to place em-phasis on algorithms, instead of a... more Methods in non-photorealistic graphics have tended to place em-phasis on algorithms, instead of artists. In contrast, we present a conceptual framework that has been designed to put the con-trol back in the hands of the artist. Combining ideas from non-photorealistic graphics ...

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Research paper thumbnail of Hierarchical implicit surface refinement

Proceedings. Computer Graphics International 2001, 2001

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Research paper thumbnail of Extending the CSG Tree. Warping, Blending and Boolean Operations in an Implicit Surface Modeling System

Computer Graphics Forum, 1999

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Research paper thumbnail of Different applications of two-dimensional potential fields for volume modeling

Current methods for building models using implicit volume techniques present problems defining ac... more Current methods for building models using implicit volume techniques present problems defining accurate and controllable blend shapes between implicit primitives. We present new methods to extend the freedom and controllability of implicit volume modeling. The main idea is to use a free-form curve to define the profile of the blend region between implicit primitives. The use of a free-form implicit curve, controlled point-by-point in the Euclidean user space, allows us to group boolean composition operators with sharp transitions or smooth free-form transitions in a single modeling metaphor. This idea is generalized for the creation, sculpting and manipulation of volume objects, while providing the user with simplicity, controllability and freedom in volume modeling. Bounded volume objects, known as "Soft objects" or "Metaballs", have specific properties. We also present binary Boolean composition operators that gives more control on the form of the transition wh...

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Research paper thumbnail of Texture Mapping the Blobtree

Recently an automatic solution to the problem of applying 2D textures to an implicit surface has ... more Recently an automatic solution to the problem of applying 2D textures to an implicit surface has been introduced [13]. The method derives a uv-texture coordinate system by tracing particles from the implicit surface to a support surface. In this paper we describe the adaptation of this algorithm to the BlobTree data structure. The BlobTreeprovides an implicit modelling system through a hierarchy of blends, CSG and warping applied to primitives. There are several problems involved in applying textures in such a general modeling system, particularly across CSG junctions. In this paper we identify these problems and introduce some possible solutions.

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Research paper thumbnail of Survey on Polygonization of Implicit Surfaces

Implicit surfaces are commonly used in image creation, modelling environments, and scientific dat... more Implicit surfaces are commonly used in image creation, modelling environments, and scientific data visualization. In this paper we survey techniques for fast visualization of implicit surfaces. The main classes of visualization algorithms are identified along with the advantages of each in the context of the different types of implicit surfaces commonly used in Computer Graphics. We focus closely on polygonization methods as they are the most suited to fast visualization. Classification and comparison of existing approaches are presented using criteria extracted from current research. This enables identification of the best strategies from the point of view of a number of specific requirements such as speed, accuracy, quality or stylization.

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Research paper thumbnail of Controllable Binary CSG Operators for "Soft Objects

International Journal of Shape Modeling, 2004

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Research paper thumbnail of Polygonal silhouette error correction: a reverse subdivision approach

International Journal of Computational Science and Engineering, 2007

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Research paper thumbnail of Precise construction and control of implicit fillets in the BlobTree

Proceedings of the Shape Modeling International (SMI 2010), 2010

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Research paper thumbnail of Interactive pen-and-ink rendering for implicit surfaces

ACM SIGGRAPH 2006 Sketches on - SIGGRAPH '06, 2006

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Research paper thumbnail of MIBlob

ACM SIGGRAPH 2004 Posters on - SIGGRAPH '04, 2004

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Research paper thumbnail of ShapeShop

ACM SIGGRAPH 2006 Courses on - SIGGRAPH '06, 2006

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Research paper thumbnail of A data-efficient collaborative modelling method using websockets and the BlobTree for over-the air networks

Proceedings of the 18th International Conference on 3D Web Technology, 2013

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Research paper thumbnail of Locally restricted blending of Blobtrees

Computers & Graphics, 2009

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Research paper thumbnail of Two-dimensional Potential Fields for Advanced Implicit Modeling Operators

Computer Graphics Forum, 2003

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Research paper thumbnail of Python for scene and model description for computer graphics

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Research paper thumbnail of Interactive decal compositing with discrete exponential maps

ACM Transactions on Graphics, 2006

A method is described for texturing surfaces using decals , images placed on the surface using lo... more A method is described for texturing surfaces using decals , images placed on the surface using local parameterizations. Decal parameterizations are generated with a novel O ( N log N ) discrete approximation to the exponential map which requires only a single additional step in Dijkstra's graph-distance algorithm. Decals are dynamically composited in an interface that addresses many limitations of previous work. Tools for image processing, deformation/feature-matching, and vector graphics are implemented using direct surface interaction. Exponential map decals can contain holes and can also be combined with conformal parameterization to reduce distortion. The exponential map approximation can be computed on any point set, including meshes and sampled implicit surfaces, and is relatively stable under resampling. The decals stick to the surface as it is interactively deformed, allowing the texture to be preserved even if the surface changes topology. These properties make exponent...

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Research paper thumbnail of A gradient-based implicit blend

ACM Transactions on Graphics, 2013

We introduce a new family of binary composition operators that solves four major problems of cons... more We introduce a new family of binary composition operators that solves four major problems of constructive implicit modeling: suppressing bulges when two shapes merge, avoiding unwanted blending at a distance, ensuring that the resulting shape keeps the topology of the union, and enabling sharp details to be added without being blown up. The key idea is that field functions should not only be combined based on their values, but also on their gradients . We implement this idea through a family of C ∞ composition operators evaluated on the GPU for efficiency, and illustrate it by applications to constructive modeling and animation.

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Research paper thumbnail of Implicit skinning

ACM Transactions on Graphics, 2013

Geometric skinning techniques, such as smooth blending or dual-quaternions, are very popular in t... more Geometric skinning techniques, such as smooth blending or dual-quaternions, are very popular in the industry for their high performances, but fail to mimic realistic deformations. Other methods make use of physical simulation or control volume to better capture the skin behavior, yet they cannot deliver real-time feedback. In this paper, we present the first purely geometric method handling skin contact effects and muscular bulges in real-time. The insight is to exploit the advanced composition mechanism of volumetric, implicit representations for correcting the results of geometric skinning techniques. The mesh is first approximated by a set of implicit surfaces. At each animation step, these surfaces are combined in real-time and used to adjust the position of mesh vertices, starting from their smooth skinning position. This deformation step is done without any loss of detail and seamlessly handles contacts between skin parts. As it acts as a post-process, our method fits well int...

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Research paper thumbnail of A Gradient-Based Implicit Blend Preprint

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Research paper thumbnail of Eastern Perspectives and the Question of Personal Expression

Methods in non-photorealistic graphics have tended to place em-phasis on algorithms, instead of a... more Methods in non-photorealistic graphics have tended to place em-phasis on algorithms, instead of artists. In contrast, we present a conceptual framework that has been designed to put the con-trol back in the hands of the artist. Combining ideas from non-photorealistic graphics ...

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Research paper thumbnail of Hierarchical implicit surface refinement

Proceedings. Computer Graphics International 2001, 2001

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Research paper thumbnail of Extending the CSG Tree. Warping, Blending and Boolean Operations in an Implicit Surface Modeling System

Computer Graphics Forum, 1999

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Research paper thumbnail of Different applications of two-dimensional potential fields for volume modeling

Current methods for building models using implicit volume techniques present problems defining ac... more Current methods for building models using implicit volume techniques present problems defining accurate and controllable blend shapes between implicit primitives. We present new methods to extend the freedom and controllability of implicit volume modeling. The main idea is to use a free-form curve to define the profile of the blend region between implicit primitives. The use of a free-form implicit curve, controlled point-by-point in the Euclidean user space, allows us to group boolean composition operators with sharp transitions or smooth free-form transitions in a single modeling metaphor. This idea is generalized for the creation, sculpting and manipulation of volume objects, while providing the user with simplicity, controllability and freedom in volume modeling. Bounded volume objects, known as "Soft objects" or "Metaballs", have specific properties. We also present binary Boolean composition operators that gives more control on the form of the transition wh...

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Research paper thumbnail of Texture Mapping the Blobtree

Recently an automatic solution to the problem of applying 2D textures to an implicit surface has ... more Recently an automatic solution to the problem of applying 2D textures to an implicit surface has been introduced [13]. The method derives a uv-texture coordinate system by tracing particles from the implicit surface to a support surface. In this paper we describe the adaptation of this algorithm to the BlobTree data structure. The BlobTreeprovides an implicit modelling system through a hierarchy of blends, CSG and warping applied to primitives. There are several problems involved in applying textures in such a general modeling system, particularly across CSG junctions. In this paper we identify these problems and introduce some possible solutions.

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Research paper thumbnail of Survey on Polygonization of Implicit Surfaces

Implicit surfaces are commonly used in image creation, modelling environments, and scientific dat... more Implicit surfaces are commonly used in image creation, modelling environments, and scientific data visualization. In this paper we survey techniques for fast visualization of implicit surfaces. The main classes of visualization algorithms are identified along with the advantages of each in the context of the different types of implicit surfaces commonly used in Computer Graphics. We focus closely on polygonization methods as they are the most suited to fast visualization. Classification and comparison of existing approaches are presented using criteria extracted from current research. This enables identification of the best strategies from the point of view of a number of specific requirements such as speed, accuracy, quality or stylization.

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Research paper thumbnail of Controllable Binary CSG Operators for "Soft Objects

International Journal of Shape Modeling, 2004

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Research paper thumbnail of Polygonal silhouette error correction: a reverse subdivision approach

International Journal of Computational Science and Engineering, 2007

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Research paper thumbnail of Precise construction and control of implicit fillets in the BlobTree

Proceedings of the Shape Modeling International (SMI 2010), 2010

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Research paper thumbnail of Interactive pen-and-ink rendering for implicit surfaces

ACM SIGGRAPH 2006 Sketches on - SIGGRAPH '06, 2006

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Research paper thumbnail of MIBlob

ACM SIGGRAPH 2004 Posters on - SIGGRAPH '04, 2004

Bookmarks Related papers MentionsView impact

Research paper thumbnail of ShapeShop

ACM SIGGRAPH 2006 Courses on - SIGGRAPH '06, 2006

Bookmarks Related papers MentionsView impact

Research paper thumbnail of A data-efficient collaborative modelling method using websockets and the BlobTree for over-the air networks

Proceedings of the 18th International Conference on 3D Web Technology, 2013

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Locally restricted blending of Blobtrees

Computers & Graphics, 2009

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Research paper thumbnail of Two-dimensional Potential Fields for Advanced Implicit Modeling Operators

Computer Graphics Forum, 2003

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Research paper thumbnail of Python for scene and model description for computer graphics

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Interactive decal compositing with discrete exponential maps

ACM Transactions on Graphics, 2006

A method is described for texturing surfaces using decals , images placed on the surface using lo... more A method is described for texturing surfaces using decals , images placed on the surface using local parameterizations. Decal parameterizations are generated with a novel O ( N log N ) discrete approximation to the exponential map which requires only a single additional step in Dijkstra's graph-distance algorithm. Decals are dynamically composited in an interface that addresses many limitations of previous work. Tools for image processing, deformation/feature-matching, and vector graphics are implemented using direct surface interaction. Exponential map decals can contain holes and can also be combined with conformal parameterization to reduce distortion. The exponential map approximation can be computed on any point set, including meshes and sampled implicit surfaces, and is relatively stable under resampling. The decals stick to the surface as it is interactively deformed, allowing the texture to be preserved even if the surface changes topology. These properties make exponent...

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Research paper thumbnail of A gradient-based implicit blend

ACM Transactions on Graphics, 2013

We introduce a new family of binary composition operators that solves four major problems of cons... more We introduce a new family of binary composition operators that solves four major problems of constructive implicit modeling: suppressing bulges when two shapes merge, avoiding unwanted blending at a distance, ensuring that the resulting shape keeps the topology of the union, and enabling sharp details to be added without being blown up. The key idea is that field functions should not only be combined based on their values, but also on their gradients . We implement this idea through a family of C ∞ composition operators evaluated on the GPU for efficiency, and illustrate it by applications to constructive modeling and animation.

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Implicit skinning

ACM Transactions on Graphics, 2013

Geometric skinning techniques, such as smooth blending or dual-quaternions, are very popular in t... more Geometric skinning techniques, such as smooth blending or dual-quaternions, are very popular in the industry for their high performances, but fail to mimic realistic deformations. Other methods make use of physical simulation or control volume to better capture the skin behavior, yet they cannot deliver real-time feedback. In this paper, we present the first purely geometric method handling skin contact effects and muscular bulges in real-time. The insight is to exploit the advanced composition mechanism of volumetric, implicit representations for correcting the results of geometric skinning techniques. The mesh is first approximated by a set of implicit surfaces. At each animation step, these surfaces are combined in real-time and used to adjust the position of mesh vertices, starting from their smooth skinning position. This deformation step is done without any loss of detail and seamlessly handles contacts between skin parts. As it acts as a post-process, our method fits well int...

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Research paper thumbnail of A Gradient-Based Implicit Blend Preprint

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