IEEE Visualization 2004 Contest Entry

PDF: PDF Document
Video: Quicktime(6.6 MB)

Remarks: In the video only the normalized vector field was used.

Investigating Hurricane Isabel using Texture Advection


Contest Entry Visualization System

Our visualization system is an interactive, timedependent, 3D multi-field representation which allows the user to investigate a combined visualization of scalar field and vector field information. The system was developed in summer 2004 in the context of the diploma thesis of Tobias Schafhitzel advised by Daniel Weiskopf and Thomas Ertl.

Criterion 1: Interactivity

Performance measurements for a Windows XP machine with an ATI Radeon X800 GPU (256 MB). The sizes of the vectorfield are stated in the first column. The generated image size is 600x600 pixels, the internal color depth for the Advection step 16 bit/channel=64 bit and the color depth for the final display 8 bit/channel=32 bit. A subsampled data of 256 x 256 x 64 maximum is considered.

Texture Advection only



64 x 64 x 16

128 x 128 x 32 137
256 x 256 x 64 34


Scalar Field Visualization



64 x 64 x 16

128 x 128 x 32 183
256 x 256 x 64 150


Combined Visualization 1 (Texture Advection and Scalar Field Visualization)



64 x 64 x 16

128 x 128 x 32 110
256 x 256 x 64 32


Combined Visualization 2 (3D Texture Advection, Scalar Field Visualization and 2D Texture Advection)



64 x 64 x 16

128 x 128 x 32 32
256 x 256 x 64 15


Criterion 2: Exploratory Support

Parameters used to manipulate the visualization:

Texture Advection and Flow visualization:

Scalar Field Representation:

2D Selection Plane and 2D High-Resolution representation


By the use of the scrollbars the user is able to combine the Flow Visualization with any Scalar Representation. For example he selects a range of lambda2 + a range of velocity + a 2D Selection Plane.

Criterion 3: Multiple Characteristics

Visualization Performed 1 - flow

3D Texture Advection + additional red Dye: 2 Materials (blue and green) are advected time-dependently using a normalized vectorfield.


Visualization Performed 2 - scalars: clouds, pressure, temperature

Representing the clouds using a luminance setting of a small range of the scalar values in the transferfunction.
Also a small range of pressure and temperature was selected and mapped on a red-green-blue color gradient.


Visualization Performed 3 - lambda2 + flow

3D Texture Advection + lambda2 scalar values: Here the transparency of the Flow Visualization is very high (Set Alpha in the transferfunction -> 0). A big range of lambda2 is selected and mapped with purple and a high opacity. Figure 3 shows a Flow Visualization with a higher opacity and white colored lambda2 values.


Visualization Performed 4 - 2D Selection- and Zoom-Plane + Scalar Visualization + 3D Texture Advection

An additional 2D Selection Plane is inserted. A High-Resolution Representation of the flow is mapped to the Zoom-Plane, using different transferfuntions for the flow and the scalar values. Also 3D Texture Advection is shown in Figure 1.


Visualization Performed 5 - 2D Selection- and Zoom-Plane + Scalar Visualization + 3D Texture Advection + 2D Texture Advection

Figure 1 shows a range of pressure mapped on a color gradient + a blue-white 3D Texture Advection + the Selection Plane with active Zoom Plane. The 2D Representation (with additional blue dye) shows the center of Isabel, distinguished by the yellow Zoom Plane. In Figure 2 and 3 the 2D representation is mapped to the Zoom Plane. Figure 4 shows the High-Resolution 2D representation, here 1024x1024 (using an interpolated vector field).
Figure 6 shows the rotation of the hurricane using 2D texture advection with an unnormalized vector field


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