The 3d streamlines module produces streamlines or stream-ribbons of a field containing a 2 or 3 element vector data component on any type of mesh. Streamlines are 3D polylines representing the pathways particles would travel based on the gradient of the vector field. At least one of the nodal data components input to the module must be a vector. The direction of travel can be specified as forwards (toward high vector magnitudes), backwards (toward low vector magnitudes), or both with respect to the vector field. Streamlines are produced by integrating a velocity field using the Runge-Kutta method with adaptive time steps.
Ports
Direction
Name
Type
Description
Input
Input Field
Field
The field to use for creating the streamlines.
Input
Input Locations Field
Field
The field to use for creating the starting locations of streamlines.
Output
Output Field
Field
The streamlines field.
Output
Output Object
Renderable
A renderable object to display.
Properties
Property
Type
Description
Allow Run
Boolean
Specifies whether the module is permitted to execute. Set to True to enable execution.
Execute
Button
Forces the module to run even if Allow Run is disabled.
Z Scale
Double
Ensures that output lines are aligned with the scaled input.
Vector Nodal Data
Choice
Specifies which vector components to use for streamline generation.
Velocity Units
String
Specifies the units of the input vector data. By default this is determined from the input field. Unlink to override manually.
Flow Direction
Choice: Backwards, Forwards, Both
Selects the direction the lines will flow.
Terminating Conditions
Property
Type
Description
Max Segments Total
Integer
The maximum allowable number of streamline segments that will be completed for each streamline. If the number of segments along a streamline exceeds the max number, the streamline is terminated at the end of the last (max) segment.
Minimum Velocity
Double
The minimum velocity that will be considered in the integration. If the magnitude of the velocity field in a region is less than this minimum value, streamlines will end in that region (or will not be produced if the gradient at a starting point is less than the min). Setting this to a lower value will produce longer streamlines (and typically more). Higher values tend to produce fewer and shorter streamlines.
Extinction Angle
Double
The maximum allowable angle between successive line segments before integration (streamline generation) should be terminated.
Output Data Options
Property
Type
Description
Export Velocity And Time
Boolean
Specifies whether velocity and time data will be included in the output field. If this option is enabled, the input Vector Nodal Data component must have proper velocity units (length/time).
Log Process Time
Boolean
Specifies that time data will be output on a logarithmic scale. This converts all time values to absolute, including those in the backward flow direction that would otherwise be negative.
Time Minimum
Double
The minimum value time data is clamped to before log processing. Useful to avoid datamap issues especially at the start of streamlines where time values are very small or zero.
Log Process Velocity
Boolean
Specifies that velocity data will be output on a logarithmic scale.
Velocity Minimum
Double
The minimum velocity value to clamp data before log processing. Helps avoid datamap issues in regions where velocity is very low or zero.