Module: Line Probe ()

Description:

The data probing module LineProbe is used to inspect scalar or vector data fields. The probes are taken along a line which may be arbitrarily placed. The controlpoints of the data probing modules determine the locations where the samples are to be taken. Line Probe has two controlpoints which are the endpoints of a line which is subdivided into a number of segments given by the Samples port or by the Distance port.

To place the controlpoints within the bounding box of the given geometry you can either type in the coordinates in the port Points (see below) or you can shift the points interactively with the mouse. The latter can be done by turning the 3D viewer into interactive mode (ESC key) and picking and moving the crosshair dragger of the current point (see Points port options to show/hide the dragger). You can also pick a location with the middle mouse button on a pickable object in the scene, e.g., an Ortho Slice or a surface, to set the current point to that location. You can change the current point to be moved by pressing 'up arrow' or 'down arrow' key while interacting in viewer window, or by clicking with left mouse button on a point (small yellowish spheres).

The plot immediately changes if the immediate mode toggle is set. Usually the sampled values are plotted against the length of the probe line in an extra plot window. If you use more than one data probing module of the same type all plotted curves will be shown in one plot window.

A module of type Extract Line Set can be connected to a Line Probe module in order to save the probe line and the sampled values.

Connections:

Data [required]
Can be connected to arbitrary 3D fields. Can also be attached to 3D input objects other than fields such as surfaces or Open Inventor geometry. In this case, the Line Probe doesn't sample any data but simply measures distances.

Ports:

Orientation

This port provides three buttons to specify the probe line orientation: perpendicular to the x-y-plane, to the x-z-plane, or to the y-z-plane. If one of these buttons is pressed, the start and end coordinates of the probe line are set to the minima and the maxima respectively of the corresponding axis and to the center of the two axes perpendicular to the probe line.

Options

The immediate option determines whether the samples are taken while the controlpoints are being moved or when the motion is finished.

If the orthogonal option is on, all points are moved in sync, when the coordinates of one point are changed with the dragger.

The customize sampling option is only available for Spline Probe.

Points

Here you can see and/or type in the coordinates of all controlpoints the data probing module makes use of. The options menu lets you toggle whether a dragger or a sphere is shown for the controlpoints. Furthemore you have the possibility to see where the line is being drawn by using the "Interactive feedback" option.

Point Size

To set the size of the controlpoints.

Evaluate

If the probe is connected to a vector field, these radio buttons are shown. If the magnitude button is set the magnitude of the vectors is shown in the plot window. With the normal+tangent button set you get the normal and tangential components as two curves. Setting the all button shows all components of the vector field as separate curves.

Plot

If the Show button is pressed a plot window appears where the sampled values are plotted against the length of the probe line. Note: There will be only one plot window regardless of how many Line Probe modules there are in your setup. Every line probe is represented in that plot window by a curve bearing the name of the corresponding module.

Follow Slice

Follow Slice

The follow slice option is only available for regular scalar fields. If it is on, the line probe's 3D point positions are set at the scalar field's ortho slice positions. A slice number port appears and lets you control the position for the probe.

Slice Number

When setting the slice number, all the points of the probe are set at the defined slice position. The orientation of the slice controling the probe points is chosen with the orientation buttons. The orientation is x-y-plane by default.

Sampling Options Port :

Control

With these radio buttons you can choose which of the following two ports are used to compute the sample points. If you have chosen the adaptive button, the module tries to keep the number of samples which can be seen in the plot window as close as possible to the number given with the appropriate slider. i.e., the more you zoom into the plot window the more exact are the curves in the plot window.

Samples

This slider allows you to choose the numbers of samples along the probe line.

Distance

This slider allows you to choose the distance between two consecutive sample points along the probeline.

Offset

This port is used to add an offset (i.e., translation) to the plot window X-Axis coordinates.

Average

Average

If take average button is ON, the Radius and Longitudinal Width ports are displayed. The average option averages the probe values by taking samples on a disk perpendicular to the sampling points and smoothes the sampled values along the sampling line(s).

Radius

The radius of the sampling disk. This slider is only shown if the above average option is chosen.

Longitudinal Width

The width determines how many sampling values are used for smoothing. This slider is only shown if the above average option is chosen.

Average options

If averaging is enabled this port selects the type of sampling. By default, the average value is reported but the user might also select the maximum or minimum value.

Commands:

getInterpol
Returns the currently used interpolation method.

setInterpol {none|linear|spline}
Sets the interpolation method. none means no interpolation at all and the sample values are taken at the controlpoints only.

getOrder
Returns the order of the spline probe.

setOrder <value>
Sets the order of the spline probe.

getPoint [<index>]
Returns the coordinate of the requested controlpoint. Index defaults to 0.

setPoint [<index>] <x> <y> <z>
Sets the coordinates of controlpoint index. Index defaults to 0.

getSamplePoints
Returns the coordinates of all points where samples are taken.

getSampledValues
Returns all sampled values.

setImmediate {0|1}
Switches the immediate mode on or off, i.e., data is shown while the probe line or point is being moved.

setOrtho {0|1}
Switches the orthogonal mode on or off, i.e., all controlpoints of a probe line are moved in sync or not.

getNumPoints
Returns the number of control points of a probe line. In case of a point probe 1 is returned.

getLength
Returns the length of the probe line. 0 in case of a point probe.