Section: Visualization Toolkit Hybrid Classes
An description of the algorithm is as follows. The filter begins by projecting the polyline points to the image (offset by the specified height offset). If the mode is non-occluded or hug, then the maximum error along each line segment is computed and placed into a priority queue. Each line segment is then split at the point of maximum error, and the two new line segments are evaluated for maximum error. This process continues until the line is not occluded by the terrain (non-occluded mode) or satisfies the error on variation from the surface (hug mode). (Note this process is repeated for each polyline in the input. Also, the maximum error is computed in two parts: a maximum positive error and maximum negative error. If the polyline is above the terrain--i.e., the height offset is positive--in non-occluded or hug mode all negative errors are eliminated. If the polyline is below the terrain--i.e., the height offset is negative--in non-occluded or hug mode all positive errors are eliminated.)
To create an instance of class vtkProjectedTerrainPath, simply invoke its constructor as follows
obj = vtkProjectedTerrainPath
obj
is an instance of the vtkProjectedTerrainPath class.
string = obj.GetClassName ()
- Standard methids for printing and determining type information.
int = obj.IsA (string name)
- Standard methids for printing and determining type information.
vtkProjectedTerrainPath = obj.NewInstance ()
- Standard methids for printing and determining type information.
vtkProjectedTerrainPath = obj.SafeDownCast (vtkObject o)
- Standard methids for printing and determining type information.
obj.SetSource (vtkImageData source)
- Specify the second input (the terrain) onto which the polyline(s) should
be projected.
vtkImageData = obj.GetSource ()
- Specify the second input (the terrain) onto which the polyline(s) should
be projected.
obj.SetProjectionMode (int )
- Determine how to control the projection process. Simple projection
just projects the original polyline points. Non-occluded projection
insures that the polyline does not intersect the terrain surface.
Hug projection is similar to non-occulded projection except that
produces a path that is nearly parallel to the terrain (within the
user specified height tolerance).
int = obj.GetProjectionModeMinValue ()
- Determine how to control the projection process. Simple projection
just projects the original polyline points. Non-occluded projection
insures that the polyline does not intersect the terrain surface.
Hug projection is similar to non-occulded projection except that
produces a path that is nearly parallel to the terrain (within the
user specified height tolerance).
int = obj.GetProjectionModeMaxValue ()
- Determine how to control the projection process. Simple projection
just projects the original polyline points. Non-occluded projection
insures that the polyline does not intersect the terrain surface.
Hug projection is similar to non-occulded projection except that
produces a path that is nearly parallel to the terrain (within the
user specified height tolerance).
int = obj.GetProjectionMode ()
- Determine how to control the projection process. Simple projection
just projects the original polyline points. Non-occluded projection
insures that the polyline does not intersect the terrain surface.
Hug projection is similar to non-occulded projection except that
produces a path that is nearly parallel to the terrain (within the
user specified height tolerance).
obj.SetProjectionModeToSimple ()
- Determine how to control the projection process. Simple projection
just projects the original polyline points. Non-occluded projection
insures that the polyline does not intersect the terrain surface.
Hug projection is similar to non-occulded projection except that
produces a path that is nearly parallel to the terrain (within the
user specified height tolerance).
obj.SetProjectionModeToNonOccluded ()
- Determine how to control the projection process. Simple projection
just projects the original polyline points. Non-occluded projection
insures that the polyline does not intersect the terrain surface.
Hug projection is similar to non-occulded projection except that
produces a path that is nearly parallel to the terrain (within the
user specified height tolerance).
obj.SetProjectionModeToHug ()
- This is the height above (or below) the terrain that the projected
path should be. Positive values indicate distances above the terrain;
negative values indicate distances below the terrain.
obj.SetHeightOffset (double )
- This is the height above (or below) the terrain that the projected
path should be. Positive values indicate distances above the terrain;
negative values indicate distances below the terrain.
double = obj.GetHeightOffset ()
- This is the height above (or below) the terrain that the projected
path should be. Positive values indicate distances above the terrain;
negative values indicate distances below the terrain.
obj.SetHeightTolerance (double )
- This is the allowable variation in the altitude of the path
with respect to the variation in the terrain. It only comes
into play if the hug projection mode is enabled.
double = obj.GetHeightToleranceMinValue ()
- This is the allowable variation in the altitude of the path
with respect to the variation in the terrain. It only comes
into play if the hug projection mode is enabled.
double = obj.GetHeightToleranceMaxValue ()
- This is the allowable variation in the altitude of the path
with respect to the variation in the terrain. It only comes
into play if the hug projection mode is enabled.
double = obj.GetHeightTolerance ()
- This is the allowable variation in the altitude of the path
with respect to the variation in the terrain. It only comes
into play if the hug projection mode is enabled.
obj.SetMaximumNumberOfLines (vtkIdType )
- This instance variable can be used to limit the total number of line
segments created during subdivision. Note that the number of input line
segments will be the minimum number that cab be output.
vtkIdType = obj.GetMaximumNumberOfLinesMinValue ()
- This instance variable can be used to limit the total number of line
segments created during subdivision. Note that the number of input line
segments will be the minimum number that cab be output.
vtkIdType = obj.GetMaximumNumberOfLinesMaxValue ()
- This instance variable can be used to limit the total number of line
segments created during subdivision. Note that the number of input line
segments will be the minimum number that cab be output.
vtkIdType = obj.GetMaximumNumberOfLines ()
- This instance variable can be used to limit the total number of line
segments created during subdivision. Note that the number of input line
segments will be the minimum number that cab be output.