Module: Cone Plot (deprecated) ()

Description:

ConePlot is a display module that can be attached to a vector field. It visualizes scalar and complex vector fields by colored objects (cones) pointing in the direction of the local flow. The cones can be animated to generate a sequence of cones "walking" through the vector field.

The module features SelectRoi, Colorfields, and arbitrary shapes to be displayed instead of cones.

The module can also generate a density based on the cone positions over time.
  Cone Plot setGhostDims 30 30 30
  Cone Plot generateGhost
The module uses a Gaussian kernel with a variance of a tenth of the maximum bounding box size of the volume. This option is computationally very expensive.

The module also exports the path of the cones as a Line Set. To generate the Line Set, call:
  Cone Plot saveAsLineSet
in the console window. The Line Set is computed with a data entry per Line Set point which represent the magnitude of the vector at this position.

ConePlot uses Open Inventor render caching. All animation steps are computed beforehand and then played back by making the appropriate parts of the scene visible. This technique requires little CPU computation but larger amounts of memory and a fast graphics card. Because of the caching step, the first pass through the animation may be slow but subsequently render passes speed up.

Press the Apply button to recompute the animation or the single plot.

Notice that Cone Plot is only provided for backwards compatibility since it has been replaced by the Particle Plot module.

Connections:

Data [required]
The 3D vector field to be visualized. It can be either 3 or 6 floats per voxel. This module works therefore with arbitrary grid topologies by sampling them uniformly.

Colormap [optional]
Port to connect a colormap object. The color is computed from the magnitude of the vectors.

Animate [optional]
Attach a Time object to control the Animate slider. Please make sure that the range of the time slider is set to integers and that 0 is within that range.

ROI [optional]

Connect a region of interest to the module and the cones will only be generated inside this region. This helps in exploring complicated vector fields.

Colorfield [optional]
Instead of the vector field applied, the module will use a second scalar field to color the cones.

Shape data [optional]

Supply a custom shape to be replicated instead of cones. Basically any geometry displayed in can be used. Be careful not to use very complex objects because the number of triangles used in this case can be a limiting factor for the speed of the animation.

Ports:

Resolution

Provides three text inputs defining the resolution of the regular array of cones in the local x- y- and z-direction. The larger these values are, the more cones are displayed.

Colormap

Port to select a colormap. The color is computed from the magnitude of the vectors.

Complex phase angle

This port will only be visible if a complex-valued vector field is connected to the module. It provides a phase slider controlling which part of the complex 3D vectors is visualized by the arrows.

A value of 0 degree corresponds to the real part, while a value of 180 degrees corresponds to the imaginary part. The display can be animated with respect to the phase by the Animate port. This way polarization properties of the field can be revealed or wave phenomena become visible.

Threshold

Any cone is removed from display which would be placed on a position with a vector length smaller than this threshold. Using this option you can "thin-out" parts of the volume, e.g., regions which would contain cones that never move.

Options

This port provides the following toggle options.

Animation: If this option is set, then two additional ports are displayed. The Time port allows you to set a time frame (from to frames). The Step size port allows you to set the time between successive time steps. Currently we use an Euler integration. The smaller the step size, the more accurately the flow field is sampled.

Show All: Shows all cones in the current animation. When switching on this mode, there is no need for animations because the animation is done by switching cones on and off.

Customize Cones: You can change the height and the bottom radius of all cones.

BlendIn: If this option is set, the size of the cones is increased or decreased at the start or end point of the animation. This behavior generates nicer graphics for continuous animations, especially in the case of ConesPerStream .

Step Size

The current implementation uses Euler integration and this defines the step size calculated by

where x(t) is the position and v(t) the velocity at time t. Please be careful to not work on stiff flow fields using this method. In general, small values result in higher accuracy and smaller path length of the cones.

If you set the value of ConesPerStream to , more than one cone is displayed at a time. Together with the loop mode of the time slider and the BlendIn option set, this creates continuous animations.

Animate

This time slider allows you to start and stop animations. If you right-click in the associated text window you can switch to loop mode which generates an infinitely long animation.

The range of the slider must be set to integer numbers. For example: 0...50 is interpreted as 50 time steps for the forward integration, or -30...30 is interpreted as 30 steps in both forward and backward directions. The modules makes sure that the increment is always 1.

Height

For cones this changes their height. If another shape is connected to the module, the port controls the global scaling of the shape.

Bottom radius

For cones this changes the radius of their base circle.