In this paper, we present a new algorithm for computing in a very efficient way the real intersection of three quadric surfaces. Our approach is based on the cylindrical decomposition ([4]) and the TOP algorithm ([10]) for analyzing the topology of a planar curve. We preform a symbolic pre-processing that allows us later to execute all numerical computations in a very accurate way.

Let [Formula: see text] be the complex 3-quadric endowed with its standard conformal structure. We study geometry of isotropic curves in text]. By an curve, we mean a nonconstant holomorphic map from Riemann surface into text], null respect to structure The relations between and number relevant classes surfaces Riemannian Lorentzian spaceforms are discussed.

Abstract We show that the K-moduli spaces of log Fano pairs $\left(\mathbb {P}^1\times \mathbb {P}^1, cC\right)$ , where C is a $(4,4)$ curve and their wall crossings coincide with VGIT quotients $(2,4)$ complete intersection curves in $\mathbb {P}^3$ . This, together recent results by Laza O’Grady, implies these form natural interpolation between GIT moduli space on {P}^1$ Baily–Borel compacti...

Today, most of the powerful graphic systems are based on 3D-triangle display methods. However, this approach generates well-known problems, like the low quality of contours and shading, and the necessity to have large amounts of primitives to display complex scenes. A way to solve these problems is to use higher level primitives, among which a very interesting one is the quadric surface. We stu...

A robust method for 3-D surface recognition based on genetic algorithms is proposed in this paper. With the help of a specilic least square fitting algorithm, the model-based 3-1) st,rfacc recognition problem is first converted into an optimization problem. Then. a genetic algorithm is used to solve the optimal problem in order to extract general quadric surfaces. Finally. all the extracted .~u...

We study nonsingular minimal surfaces of general type with pg = 6 and K2 = 13 whose canonical image is contained in a single nonsingular quadric. We show that under these assumptions, such surfaces are regular and their canonical ideal has codimension 3. Led by Buchsbaum–Eisenbud’s structure theorem, we define a map of S into a weighted Grassmannian, which factors through an embedding of the ca...

Curved screens are increasingly being used for high-resolution immersive visualization environments. We describe a new technique to display seamless images using overlapping projectors on curved quadric surfaces such as spherical or cylindrical shape. We define a new quadric image transfer function and show how it can be used to achieve sub-pixel registration while interactively displaying two ...

Kinematic mapping is used for preliminary development of an algorithm for the approximate synthesis of planar four-bar mechanisms for rigid body guidance. Both dyad type and dimensions are determined. Planar mechanism coupler motions are represented as the curves of intersection of a pair of quadric constraint surfaces, one for each of two dyads. The problem reduces to identifying the two best ...