Apparatus and method for finding visible points in a cloud point

Abstract

The subject matter discloses a method of determining whether a point in a computerized image is visible from a viewpoint; said image is represented as a point cloud, the method comprising: performing inversion on a the vicinity of the point thus creating a computerized inversed objects each point in the vicinity of the point is related to a parallel point in the computerized inversed object and obtaining a convex hull of the inversed object; the point is likely to be visible from the viewpoint in case it belongs to the point set composing the convex hull. The method is also useful for shadow casting and for determining the location of an image-capturing device within a volume

Description

RELATED APPLICATIONS[0001]This application claims priority from provisional application No. 60 / 867,725 filed Nov. 27, 2006, which is hereby incorporated by reference.BACKGROUND OF THE INVENTION[0002]1. Field of the Invention[0003]The present invention relates to computational geometry in general and to determining visibility of points from a predefined point of view in particular.[0004]2. Discussion of the Related Art[0005]Computer graphics employ processing units to determine visibility of points. Visibility determination is the process of determining whether a particular point in space is visible from a specific point of view. Determining the visibility of a surface of an object quickly and efficiently has been a fundamental problem in computer graphics.[0006]Determining visible points is useful for indicating field of view from a specific point, for defining shadow casting for the gaming industry, for the security industry and the like. For example, finding visible points may res...

AI Technical Summary

Benefits of technology

[0018]It is another aspect of the subject matter to disclose a method for determining an optimal location for positioning an image capturing device within a volume, the method comprising: obtaining a plurality of points to be visible from the image capturing device; performing inversion on points located in the vicinity of the plurality of points thus creating a computerized inversed object, each point in the vicinity of the plurality of point is translated to a parallel point in the computerized inversed object; defining a convex hull of the inversed object; determining if a point of the plurality of points is visible from the viewpoint according to the position of its parallel point on t

Problems solved by technology

Determining the visibility of a surface of an object quickly and efficiently has been a fundamental problem in computer graphics.

Reconstruction of the surface from the points requires considerable time and computation resources.

Moreover, camera rotation or change in the field of view requires time-consuming visibility recalculation.

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