158 research outputs found
Feature based volumes for implicit intersections.
The automatic generation of volumes bounding the intersection of two implicit surfaces (isosurfaces of real functions of 3D point coordinates) or feature based volumes (FBV) is presented. Such FBVs are defined by constructive operations, function normalization and offsetting. By applying various offset operations to the intersection of two surfaces, we can obtain variations in the shape of an FBV. The resulting volume can be used as a boundary for blending operations applied to two corresponding volumes, and also for visualization of feature curves and modeling of surface based structures including microstructures
Complex skeletal implicit surfaces
Recent research has demonstrated the effectiveness of complex skeletal primitives such as subdivision curves and
surfaces in implicit surface modeling. This paper presents a hierarchichal modeling system with an automatic levels
of detail management for a simpler modeling with an accelerated rendering. We manage levels of detail with smooth
transitions and tree optimizations speeding up visualization by an order of magnitude, which allows an interactive editing
of the shapes
Polygonization of Multi-Component Non-Manifold Implicit Surfaces through A Symbolic-Numerical Continuation Algorithm
In computer graphics, most algorithms for sampling implicit surfaces
use a 2-points numerical method. If the surface-describing
function evaluates positive at the first point and negative at the second
one, we can say that the surface is located somewhere between
them. Surfaces detected this way are called sign-variant implicit
surfaces. However, 2-points numerical methods may fail to detect
and sample the surface because the functions of many implicit surfaces
evaluate either positive or negative everywhere around them.
These surfaces are here called sign-invariant implicit surfaces. In
this paper, instead of using a 2-points numerical method, we use a
1-point numerical method to guarantee that our algorithm detects
and samples both sign-variant and sign-invariant surface components
or branches correctly. This algorithm follows a continuation
approach to tessellate implicit surfaces, so that it applies symbolic
factorization to decompose the function expression into symbolic
components, sampling then each symbolic function component separately.
This ensures that our algorithm detects, samples, and triangulates
most components of implicit surfaces
Triangulation of uniform particle systems: its application to the implicit surface texturing
Particle systems, as originally presented by Witkin and Heckbert [32], offer an elegant solution to sample implicit
surfaces of arbitrary genus, while providing an extremely regular distribution of samples over the surface. In this
paper, we present an ef cient technique that uses particle systems to rapidly generate a triangular mesh over an
implicit surface, where each triangle is almost equilateral. The major advantage of such a triangulation is that
it minimizes the deformations between the mesh and the underlying implicit surface. We exploit this property
by using few triangular texture samples mapped in a non-periodic fashion as presented by Neyret and Cani [16].
The result is a pattern-based texturing method that maps homogeneous non-periodic textures to arbitrary implicit
surfaces, with almost no deformation
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