Drawings SDK Developer Guide > Working with .dwg Files > Working with Entities > Working with Specific Entitites > Working with Rays > Specific Ray Properties
Specific Ray Properties

The ray object uses base point and direction vector properties to define the geometry to be drawn. In examples, the pRay variable stores a pointer to the ray object.

Base Point

The Base Point property defines the base point of the ray in three-dimensional coordinates. The base point is the point from which the ray begins, outward in the specified direction. Rotating and moving the ray are performed relative to the base point. The base point has the coordinates (0,0,0) by default.

To get the base point, use the basePoint() method which does not have arguments and returns the three-dimensional point as an instance of the OdGePoint3d type. For example:


OdGePoint3d base = pRay->basePoint();
odPrintConsoleString(L"\nBase point = (%g,%g,%g)", base.x, base.y, base.z);

To set the base point, use the setBasePoint() method which requires the three-dimensional point as an argument of the OdGePoint3d type and does not return a value. For example:


OdGePoint3d point(4, 1, 5);
pRay->setBasePoint(point);

Direction

The Direction property defines the direction of the ray in three-dimensional coordinates. The direction is automatically converted to a unit vector which defines the direction from the base point. The direction vector has the coordinates (0,0,1) by default.

To get the direction, use the unitDir() method which does not have arguments and returns the three-dimensional vector as an instance of the OdGeVector3d type. For example:


OdGeVector3d vector = pRay->unitDir();
odPrintConsoleString(L"\nDirection = (%g,%g,%g)", vector.x, vector.y, vector.z);

To set the direction, use the setUnitDir() method which requires the three-dimensional vector as an argument of the OdGeVector3d type and does not return a value. For example:


OdGeVector3d direct(0.207, 0.415, 0.207);
pRay->setUnitDir(direct);

The method automatically converts the specified coordinates to a unit vector. For example:


pRay->setUnitDir( OdGeVector3d(4.5, 5.2, 6.8) );
OdGeVector3d result = pRay->unitDir();
odPrintConsoleString(L"\n(%g, %g, %g)", result.x, result.y, result.z);
// (0.465304, 0.537685, 0.703126)

See Also

Working with Rays

Computed Ray Properties

Specific Infinite Line Properties

Example of Working with the Ray Object

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