English
Related papers

Related papers: A Trisectrix from a Carpenter's Square

200 papers

Algorithms that decompose a manifold into simple pieces reveal the geometric and topological structure of the manifold, showing how complicated structures are constructed from simple building blocks. This note describes a way to…

Geometric Topology · Mathematics 2022-06-08 Mark Bell , Joel Hass , J. Hyam Rubinstein , Stephan Tillmann

We describe a new algorithm to compute the geometric intersection number between two curves, given as edge vectors on an ideal triangulation. Most importantly, this algorithm runs in polynomial time in the bit-size of the two edge vectors.…

Geometric Topology · Mathematics 2016-05-12 Mark C. Bell , Richard C. H. Webb

The problem of defining correctly geometric objects such as the curvature is a hard one in discrete geometry. In 2009, Ollivier defined a notion of curvature applicable to a wide category of measured metric spaces, in particular to graphs.…

Differential Geometry · Mathematics 2014-03-10 Benoît Loisel , Pascal Romon

Line intersection with convex and un-convex polygons or polyhedron algorithms are well known as line clipping algorithms and very often used in computer graphics. Rendering of geometrical problems often leads to ray tracing techniques, when…

Graphics · Computer Science 2022-08-10 Vaclav Skala

In this paper, we define some new associated curves as integral curves of a vector field generated by Frenet vectors of tangent indicatrix of a curve in Euclidean 3-space. We give some relationships between curvatures of these curves. By…

Differential Geometry · Mathematics 2019-10-16 Burak Sahiner

Gay and Kirby introduced trisections which describe any closed oriented smooth 4-manifold $X$ as a union of three four-dimensional handlebodies. A trisection is encoded in a diagram, namely three collections of curves in a closed oriented…

Geometric Topology · Mathematics 2021-06-21 Vincent Florens , Delphine Moussard

In this note, we provide a generalization for the definition of a trisection of a 4-manifold with boundary. We demonstrate the utility of this more general definition by finding a trisection diagram for the Cacime Surface, and also by…

Geometric Topology · Mathematics 2020-08-24 José Román Aranda , Jesse Moeller

Given a trivalent graph in the 3-dimensional Euclidean space, we call it a discrete surface because it has a tangent space at each vertex determined by its neighbor vertices. To abstract a continuum object hidden in the discrete surface, we…

Differential Geometry · Mathematics 2022-03-31 Motoko Kotani , Hisashi Naito , Chen Tao

A horn angle between a circle and its tangent is considered in Euclid's Elements, and Euclid remarks that it is smaller than any acute rectilinear angle. Already in antiquity, Proclus wondered whether it is possible to bisect horn angles.…

Metric Geometry · Mathematics 2022-06-22 Sergiy Koshkin

A completely well-centered tetrahedral mesh is a triangulation of a three dimensional domain in which every tetrahedron and every triangle contains its circumcenter in its interior. Such meshes have applications in scientific computing and…

Computational Geometry · Computer Science 2008-08-06 Evan VanderZee , Anil N. Hirani , Damrong Guoy

A simplified trisection is a trisection map on a 4-manifold such that, in its critical value set, there is no double point and cusps only appear in triples on innermost fold circles. We give a necessary and sufficient condition for a…

Geometric Topology · Mathematics 2017-11-09 Kenta Hayano

A common representation of a three dimensional object in computer applications, such as graphics and design, is in the form of a triangular mesh. In many instances, individual or groups of triangles in such representation need to satisfy…

Optimization and Control · Mathematics 2019-04-08 Valentin R. Koch , Hung M. Phan

A number $N$ is a triangular number if it can be written as $N = t(t + 1)/2$ for some nonnegative integer number $t$. A triangular number $N$ is called square if it is a perfect square, that is, $N = d^2$ for some integer number $d$. Square…

Number Theory · Mathematics 2026-02-20 Vladimir Gurvich , Mariya Naumova

The aim of our paper is to render an object in 3-dimension using a set of its orthographic views. Corner detector (Harris Detector) is applied on the input views to obtain control points. These control points are projected perpendicular to…

Computer Vision and Pattern Recognition · Computer Science 2026-04-01 Sunil Tiwari , Payal Fofadiya , Vicky Vishwakarma

The history of the isoptic curves goes back to the 19th century, but nowadays the topic is experiencing a renaissance, providing numerous new results and new applications. First, we define the notion of isoptic curve and outline some of the…

Differential Geometry · Mathematics 2023-04-18 Géza Csima

In 1998 A. Connes proposed an algebraic proof of Morley's trisector theorem. He observed that the points of intersection of the trisectors are the fixed points of pairwise products of rotations around vertices of the triangle with angles…

Metric Geometry · Mathematics 2016-05-31 Pierre Godard

For a given triangle $\triangle ABC$, we define two sequences of points on line $BC$ and provide their generalizations to real functions such that centers of circumscribed circles around $A$ and adjacent points in subsequences generate a…

Algebraic Geometry · Mathematics 2021-10-08 Andrija Živadinović , Veljko Toljić

Translation from the Latin of "Annotationes in locum quendam Cartesii ad circuli quadraturam spectantem" (1763). The passage Euler is referring to is the "Excerpta" in part 6, p. 6 of Descartes' 1701 "Opuscula posthuma". Before reading this…

History and Overview · Mathematics 2009-04-16 Leonhard Euler

In this paper, we develop new techniques for understanding surfaces in $\mathbb{CP}^2$ via bridge trisections. Trisections are a novel approach to smooth 4-manifold topology, introduced by Gay and Kirby, that provide an avenue to apply…

Geometric Topology · Mathematics 2025-03-11 Peter Lambert-Cole

This tutorial explains how to use piecewise cubic B\'ezier curves to draw arbitrarily oriented ellipses and elliptical arcs. The geometric principles discussed here result in strikingly simple interfaces for graphics functions that can draw…

Graphics · Computer Science 2024-08-12 Jerry R. Van Aken