2 research outputs found
ManifoldPlus: A Robust and Scalable Watertight Manifold Surface Generation Method for Triangle Soups
We present ManifoldPlus, a method for robust and scalable conversion of
triangle soups to watertight manifolds. While many algorithms in computer
graphics require the input mesh to be a watertight manifold, in practice many
meshes designed by artists are often for visualization purposes, and thus have
non-manifold structures such as incorrect connectivity, ambiguous face
orientation, double surfaces, open boundaries, self-intersections, etc.
Existing methods suffer from problems in the inputs with face orientation and
zero-volume structures. Additionally most methods do not scale to meshes of
high complexity. In this paper, we propose a method that extracts exterior
faces between occupied voxels and empty voxels, and uses a projection-based
optimization method to accurately recover a watertight manifold that resembles
the reference mesh. Compared to previous methods, our methodology is simpler.
It does not rely on face normals of the input triangle soups and can accurately
recover zero-volume structures. Our algorithm is scalable, because it employs
an adaptive Gauss-Seidel method for shape optimization, in which each step is
an easy-to-solve convex problem. We test ManifoldPlus on ModelNet10 and
AccuCity datasets to verify that our methods can generate watertight meshes
ranging from object-level shapes to city-level models. Furthermore, through our
experimental evaluations, we show that our method is more robust, efficient and
accurate than the state-of-the-art. Our implementation is publicly available
Fast Tetrahedral Meshing in the Wild
We propose a new tetrahedral meshing method, fTetWild, to convert triangle
soups into high-quality tetrahedral meshes. Our method builds on the TetWild
algorithm, replacing the rational triangle insertion with a new incremental
approach to construct and optimize the output mesh, interleaving triangle
insertion and mesh optimization. Our approach makes it possible to maintain a
valid floating-point tetrahedral mesh at all algorithmic stages, eliminating
the need for costly constructions with rational numbers used by TetWild, while
maintaining full robustness and similar output quality. This allows us to
improve on TetWild in two ways. First, our algorithm is significantly faster,
with running time comparable to less robust Delaunay-based tetrahedralization
algorithms. Second, our algorithm is guaranteed to produce a valid tetrahedral
mesh with floating-point vertex coordinates, while TetWild produces a valid
mesh with rational coordinates which is not guaranteed to be valid after
floating-point conversion. As a trade-off, our algorithm no longer guarantees
that all input triangles are present in the output mesh, but in practice, as
confirmed by our tests on the Thingi10k dataset, the algorithm always succeeds
in inserting all input triangles