Three-Dimensional Data Visualization in SAOImage DS9 Version 7

To further visualize 3-D data in SAOImage DS9 v.7, a new “Frame 3D” module allows users to view data cubes in multiple dimensions by rotation in azimuth and elevation. The result is improved data interaction at different orientations (see Figure 2). Frame 3D implements a simple ray-trace algorithm. For each pixel on the screen, a ray is projected back into the view volume, based on the current viewing parameters, and returns a data value if the ray intersects the data cube. The time it takes to render depends on the zoom factor and on how many rays are needed to project the data cube onto the screen in the view volume. Frame 3D works on all hardware platforms currently supported by DS9, including 32-bit and 64-bit versions of Linux and MacOSX, and 32-bit versions of Windows and Solaris.

In the new 3-D frame of SAOImage DS9, all of the previous 2-D graphics, regions, cross hairs, contours, and coordinate grids are available, and they are applied to the current slice as selected by the user. The user can also crop the data cube for all three axes to view just a sub-region of the data. Moreover, the option exists to create mpeg movies from 3-D astronomical data sets, either by stepping through the third dimension in a 2-D view, or by rotating the data cube in azimuth or elevation. The user may generate 3-D images in PostScript, jpeg, tiff, and other printable formats, just as in the 2-D case. Analysis macros for SAOImage DS9 have been enhanced to fully support the new 3-D module, allowing the user to invoke external analysis tasks for the current view parameters and to return results back into SAOImage DS9 in the form of text, plot, 2-D image, or 3-D image.

Funding for 3-D data visualization in SAOImage DS9 was provided by the Webb mission office at the Institute.


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