[vtkusers] vtk in terrain visualization

[Joey Mukherjee]

>   I am now working with vtk in terrain visualization.
>Suppose that my data are evenly distributed on the
>joints of an unstructured grid, and the scalar data
>act as elevations. How can I build the trianglation
>and then render it?

I do something similar by using vtkDelaunay2D to do the triangulation and the 
vtkElevationFilter on the scalar data to make the data look elevated as a 
terrain.  

>Moreover, if there are also some wheather phenomena,
>e.g. fog or cloud, to be portrayed over the landscape,
>what kind of classes shall i pay attention to? Is it
>difficult to create animation using vtk?

You would create another actor to do the weather phenomena, but AFAIK there is 
no automatic way to do it.  I create animations by using the 
vtkOffscreenRenderWindow to make new pictures and then use ImageMagick to join 
them into an animated GIF.  That may or may not be the solution for you.

I am attaching a small pic which shows the vtkDelaunay2D in action over the 
vtkEarthSource.  I am using the vtkElevationFilter, but in the picture, I have 
that turned off since it creates too many mountains which looks funny to my 
eyes; especially since the colors relay the same information.  

For those interested, this is an image of the aurora from the Dynamics Explorer 
I satellite in 1981.  The spikes are errors in the telemetry, and not an 
artifact of the triangulation.

Joey

+--------------------------------------------------------------------------+
+                                                                          +
+     Joey Mukherjee                 "The price of freedom is eternal      +
+     joey at swri.org                   vigilance, or $12.50 as seen on      +
+                                     E-Bay...                             +
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