Straight Supported Versions 1 Subtype of Manifold Fields The class is defined by the following fields: Entity/Object Variable Description integer Version integer d Space dimension Transform Transformation double[d] root The point from which the ray starts double[d] dir The direction in which the ray points double pscale Parameter scale Description This manifold defines an infinite straight line in the two or three dimensional space. It is represented by a point and a unit vector specifying the direction. A straight also has a scale factor for the parameterization, so the parameter values can be made invariant under transformation. If not specified the value of this parameter is set to 1.0. A straight line is an open curve that is not periodic. It is parameterized as: pos = root + u*pscale*dir where u is the parameter. Example 8 Straight # class 0 0 # version 3 # sdim 0 3 1 # transformation 1.3 0.8 0.0 # root point -1 0 0 # direction 1 # parameter scale See also Plane