surface streamlines
The surface streamlines module produces streamlines on any surface based on its slopes. Streamlines are 3D polylines representing the paths particles would travel based on the slopes of the input surface. The direction of travel can be specified as downhill or uphill. A velocity table allows mapping surface slopes to velocities for time-based output.
Ports
| Direction | Name | Type | Description |
|---|---|---|---|
| Input | Input Surface | Field | The surface to use for creating the streamlines. |
| Input | Input Locations Field | Field | The field to use for creating the starting locations of streamlines. |
| Input | Z Scale | Number | The factor for vertical scaling. |
| Output | Output Field | Field | The streamlines field. |
| Output | Output Object | Renderable | A renderable object to display. |
Properties
| Property | Type | Description |
|---|---|---|
| Allow Run | Boolean | Determines whether the module is allowed to execute. Set to True to allow this module to run. |
| Execute | Button | The Execute button forces the module to run even when Allow Run has been turned off. |
| Z Scale | Double | The Z Scale is required to ensure that lines are matched to scaled input. |
| Velocities | Slope Array | The Velocities table specifies the velocities along the surface at given slopes. |
| Flow Direction | Choice: Downhill, Uphill, Both | The Flow Direction allows the user to select 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 this value, the streamline is terminated at the end of the last 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 value, streamlines will end in that region. Setting this to a lower value will produce longer streamlines. Higher values tend to produce fewer and shorter streamlines. |
| Minimum Slope | Double | The absolute minimum slope in degrees that will be considered in the integration. If the slope in a region is less than this value, streamlines will end in that region. Setting this to a lower value will produce longer streamlines. 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 |
|---|---|---|
| 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. This is useful to avoid datamap issues especially at the start of streamlines where time values are very small or zero. |