Method and system for defining geometric relations in a computer aided design system

摘要

A computer aided design system assists the user in defining and editing geometric objects. It proposes several useful geometric relations between the cursor position and the already defined geometric object independent of the cursor position. The user may accept one of the proposals, or reject all of them. For example, if an already defined circle is within the catch range of the cursor position, the system proposes to draw a line from the cursor position to the center of the circle, and it proposes tangents from the cursor position to the circle.