The Globe application displays a 2 or 3 dimensional data set as a raster
image on a globe. Optionally, it can use the same or a second data set
to represent a perspective height. The image may be either a single slice
or a three slice RGB composite. One or two data sets may be loaded; their
names are given in the upper left corner of the window. If there is just
one data set, then it will also act as the height field. Datasets
may be of different size but should cover the same region of the globe.
The rendered image is three dimensional and may be rotated, panned and
zoomed. The application window may be re-sized with the size of the rendered
globe adjusting accordingly.
Pan Zoom: This button brings up the PanZoom Slider tool already linked to Globe without the need to go to the Tools menu. This control may not be unlinked from Globe, although it may be used to drive other applications. The PanZoom Slider may be killed by clicking on the button again.
LightTool: This button brings up a LightTool already linked into Globe that will control details of the lighting calculations. See documentation on the LightTool application for more information.
Image: Renders a color image on the globe when on. A wire mesh is drawn when off. Making manipulations with the image off may be convenient with a big data set because moderate delays occur before drawing images from large data sets.
RGB: This button drastically affects how Globe displays its data. When RGB mode is turned on (by pressing the button---green means on), three slices are displayed simultaneously. One slice is displayed in monochrome red, one in green, and one in blue. Use an RGBSlider to choose three different slices for this mode. If all three slices are the same one, then RGB mode just turns the image monochrome grey. That's probably not what you want.
Lights On: Hitting this button will turn on simulated lighting. The globe is drawn with one light source which apparently comes from over the user's right shoulder. Turning on lights will make small surface details much more noticeable at the cost of some display time. Use the Light tool to change some of the lighting parameters.
Height: The data are rendered not at a constant elevation, but rather with a height determined by the data in the height field. The scale of the height is controlled by the thumbwheel with upward rotation producing greater heights.
Expand/Normal Colors temporarily changes the color palette used to display the image. If the colors are expanded, the palette covers only the range of data values in the current slice. If the colors are normal, the palette covers all the data values in the whole database.
Flat Shading/Gouraud : The globe will be rendered without/with Gouraud shading. Gouraud shading makes color intensities vary smoothly by interpolating the color between data points. The difference will be most noticeable when the globe is large or when the number of data points in the original data set is small. In addition, when height is enabled, the Gouraud shaded globe will be smoothly drawn, while with Gouraud shading off each data point will be rendered as a distinct square at a separate height. The Gouraud shading also determines whether the height is interpolated.
Overlays
The Overlay menu allows the addition of overlay graphics onto the image
drawn. Standard overlays include a grid, 2 coastline projections (one for
longitudes 0-360, one for longitudes labeled -180 to 180). If an overlay
is selected, it will be drawn, re-selecting it removes it. For more information,
see overlays.
Applications to Connect This Application to
None
Tricks and Gotchas
If the image is only partially drawn, try re-sizing the window slightly
to force a re-draw.