Defines a cutting plane applied to spatial elements.

    typedef struct {
        double             a;
        double             b;
        double             c;
        double             d;
        double             xb;
        double             xe;
        double             nx;
        double             ny;
        short              cutElem;
        short              filler_1;
        API_AttributeIndex material;
        API_Coord          **coords;
        Int32              **pends;
        API_PolyArc        **parcs;
    } API_Gable;



a, b, c, d
Plane coefficients relative to the parent element.
xb, xe
Distance of vertical cut planes from local origin.
nx, ny
Normal vector of vertical cut planes (nz always 0.0).
Element the gable is generated from (output only).
Material for the cut surface (output only).
Coordinate array, not nullptr if cut is limited to a polygon.
Polygon endpoints; see API_Polygon for more information.
Polygon arcs; see API_PolyArc and API_Polygon for more information.



The a, b, c, d plane coefficients are the parameters of the plane equation:

ax + by + cz = d

Where x, y and z are points in 3D space, a, b and c are the x, y and z components of the surface normal, and d is the distance value. A point whose components are put into x, y and z is on the plane if the above equality is satisfied.

All gable data is defined in the local coordinate system of the element.

The picture below shows how gable parameters should be interpreted for curved walls:


Note that the coordinates of the limit polygon are transformed (shifted and rotated) into a position relative to the first edge of the zone polygon. To get the real gable polygon coordinates you should transform them back.

Check the Dump Zone function in the Element_Manager example project.



Version: API 2.1 or later
Header: APIdefs_Elements.h


See Also

API_ElementMemo, API_AttributeIndex
API Types