Documentation for vtkStreamLine

vtkStreamLine - generate streamline in arbitrary dataset

Super Class: vtkStreamer

Description:

vtkStreamLine is a filter that generates a streamline for an arbitrary dataset. A streamline is a line that is everywhere tangent to the vector field. Scalar values also are calculated along the streamline and can be used to color the line. Streamlines are calculated by integrating from a starting point through the vector field. Integration can be performed forward in time (see where the line goes), backward in time (see where the line came from), or in both directions. It also is possible to compute vorticity along the streamline. Vorticity is the projection (i.e., dot product) of the flow rotation on the velocity vector, i.e., the rotation of flow around the streamline. vtkStreamLine defines the instance variable StepLength. This parameter controls the length of the line segments used to define the streamline. The streamline(s) will consist of one (or more) polylines with line segment lengths of size StepLength. Smaller values reduce in more line primitives but smoother streamlines. The StepLength instance variable is defined in terms of time (i.e., the distance that the particle travels in the specified time period). Thus, the line segments will be smaller in areas of low velocity and larger in regions of high velocity. (NOTE: This is different than the IntegrationStepLength defined by the superclass vtkStreamer. IntegrationStepLength is used to control integration step size and is expressed as a fraction of the cell length.) The StepLength instance variable is important because subclasses of vtkStreamLine (e.g., vtkDashedStreamLine) depend on this value to build their representation.

 

See Also:

vtkStreamer vtkDashedStreamLine vtkStreamPoints

 

Methods:

void vtkStreamLine ()
const char *GetClassName ()
void PrintSelf (unknown & ,vtkIndent )
static vtkStreamLine *New ()
void SetStepLength (float )
float GetStepLength ()
void Execute ()

 

Detailed Method Descriptions:

Construct object with step size set to 1.0.

static vtkStreamLine *New ()

Specify the length of a line segment. The length is expressed in terms of elapsed time. Smaller values result in smoother appearing streamlines, but greater numbers of line primitives.

void SetStepLength (float )
float GetStepLength ()