February 20
Yuan Chen |
A Volumetric Method for Building Complex
Models from Range Images
Brian Curless, Marc Levoy.
Proceedings of SIGGRAPH 96. pp. 303-312, 1996.
Abstract
A number of techniques have been developed for reconstructing surfaces
by integrating groups of aligned range images. A desirable set of
properties for such algorithms includes: incremental updating,
representation of directional uncertainty, the ability to fill gaps in
the re-construction, and robustness in the presence of outliers. Prior
algorithms possess subsets of these properties. In this paper, we
present a volumetric method for integrating range images that possesses
all of these properties. Our volumetric representation consists of a
cumulative weighted signed distance function. Working with one range
image at a time, we first scan-convert it to a distance function, then
combine this with the data already acquired using a simple additive
scheme. To achieve space efficiency, we employ a run-length encoding of
the volume. To achieve time efficiency, we resample the range image to
align with the voxel grid and traverse the range and voxel scanlines
synchronously. We generate the final manifold by extracting an
isosurface from the volumetric grid. We show that under certain
assumptions, this isosurface is optimal in the least squares sense. To
fill gaps in the model, we tessellate over the boundaries between
regions seen to be empty and regions never observed. Using this method,
we are able to integrate a large number of range images (as many as 70)
yielding seamless, high-detail models of up to 2.6 million triangles. |
February 27
Budi Purnomo
|
Automatic
Reconstruction of B-Spline Surfaces of Arbitrary Topological Type
Matthias Eck, Hugues Hoppe.
Proceedings of SIGGRAPH 96. pp. 325-334. 1996.
Abstract
Creating freeform surfaces is a challenging task even with advanced
geometric modeling systems. Laser range scanners offer a promising
alternative for model acquisition - the 3D scanning of existing objects
or clay maquettes. The problem of converting the dense point sets
produced by laser scanners into useful geometric models is referred to
as surface reconstruction. In this paper, we present a procedure for
reconstructing a tensor product B-spline surface from a set of scanned
3D points. Unlike previous work which considers primarily the problem of
fitting a single B-spline patch, our goal is to directly reconstruct a
surface of arbitrary topological type. We must therefore define the
surface as a network of B-spline patches. A key ingredient in our
solution is a scheme for automatically constructing both a network of
patches and a parametrization of the data points over these patches. In
addition, we define the B-spline surface using a surface spline
construction, and demonstrate that such an approach leads to an
efficient procedure for fitting the surface while maintaining tangent
plane continuity. We explore adaptive refinement of the patch network in
order to satisfy user-specified error tolerances, and demonstrate our
method on both synthetic and real data.
|
March 6
Jatin Chhugani
|
Simple
Algorithm for Homeomorphc Surface Reconstruction
Nina Amenta, Sunghee Choi, Tamal Dey, and Naveen Keekha
Proceedings of the 16th Annual Symposium on Computational Geometry. pp.
213-222. 2000. |
March 20
Jonathan Cohen
|
Spiraling
Edge: Fast Surface Reconstruction from Partially Organized Sample Points
Patricia J. Crossno, Edward S. Angel.
IEEE Visualization '99. pp. 317-324. 1999.
Abstract
Many applications produce three-dimensional points that must be further
processed to generate a surface. Surface reconstruction algorithms that
start with a set of unorganized points are extremely time-consuming.
Sometimes, however, points are generated such that there is additional
information available to the reconstruction algorithm. We present
Spiraling Edge, a specialized algorithm for surface reconstruction that
is three orders of magnitude faster than algorithms for the general
case. In addition to sample point locations, our algorithm starts with
normal information and knowledge of each point's neighbors. Our
algorithm produces a localized approximation to the surface by creating
a star-shaped triangulation between a point and a subset of its nearest
neighbors. This surface patch is extended by locally triangulating each
of the points along the edge of the patch. As each edge point is
triangulated, it is removed from the edge and new edge points along the
patch's edge are inserted in its place. The updated edge spirals out
over the surface until the edge encounters a surface boundary and stops
growing in that direction, or until the edge reduces to a small hole
that is filled by the final triangle.
|
March 27
Subodh Kumar
|
Surface
Reconstruction based on Lower Dimensional Localized Delaunay
Triangulation
M. Gopi, S. Krishnan, C. T. Silva.
Computer Graphics Forum. 19 (3). 2000.
Abstract
We present a fast, memory efficient algorithm that generates a manifold
triangular mesh S passing through a set of unorganized points P
R3. Nothing is assumed about the geometry, topology or
presence of boundaries in the data set except that P is sampled
from a real manifold surface. The speed of our algorithm is derived from
a projection-based approach we use to determine the incident faces on a
point. We define our sampling criteria to sample the surface and
guarantee a topologically correct mesh after surface reconstruction for
such a sampled surface. We also present a new algorithm to find the
normal at a vertex, when the surface is sampled according our given
criteria. We also present results of our surface reconstruction using
our algorithm on unorganized point clouds of various models.
|
April 3
Sudhir Vishnawath
|
Parameterization
for reconstruction of 3D freeform objects from laser-scanned data based
on a PDE method
J. Barhak, A. Fischer.
The Visual Computer. 17 (6). pp. 353-369. 2001.
Abstract
In reverse engineering, laser scanners are commonly used since 3D data
is sampled fast and accurately relative to other systems. However, they
provide an enormous amount of irregular data that requires intensive
reconstruction processing, based on the parameterization and surface
fitting stages. Selection of an appropriate parameterization is
essential for topology reconstruction as well as surface fitness.
Current parameterization methods have topological problems, leading to
undesired noisy self-intersecting surfaces. In this paper, a new
adaptive parameterization PDE (partial differential equation) method is
proposed for sculptured objects that were scanned from a single
direction. The method is based on calculating a PDE
non-self-intersecting parametric grid, and then fitting the base surface
using CMA (control mesh approximation) and adaptive GDA (gradient
descent approximation) methods.
|
April 10
Chris Niski
|
High-quality
texture reconstruction from multiple scans
Fausto Bernardini, Ioana M. Martin, Holly Rushmeier.
IEEE Transactions on Visualization and Computer Graphics. 7
(4). pp. 318-332. 2001.
Abstract
The creation of three-dimensional digital content by scanning real
objects has become common practice in graphics applications for which
visual quality is paramount, such as animation, e-commerce, and virtual
museums. While a lot of attention has been devoted recently to the
problem of accurately capturing the geometry of scanned objects, the
acquisition of high-quality textures is equally important, but not as
widely studied. In this paper, we focus on methods to construct accurate
digital models of scanned objects by integrating high-quality texture
and normal maps with geometric data. These methods are designed for use
with inexpensive, electronic camera-based systems in which
low-resolution range images and high-resolution intensity images are
acquired. The resulting models are well-suited for interactive rendering
on the latest-generation graphics hardware with support for bump
mapping. Our contributions include new techniques for processing range,
reflectance, and surface normal data, for image-based registration of
scans, and for reconstructing high-quality textures for the output
digital object.
|
April 17
Sam Tannouri
|
Undersampling and oversampling in sample
based shape modeling
T. K. Dey, J. Giesen, S. Goswami, J. Hudson, R. Wenger, Wulue Zhao.
IEEE Visualization 2001. pp. 83-90, 2001. |