The bubbleviz module generates spheres of various radii and colors at
the element locations of a 1D, 2D or 3D field. This is a "cuberille" style
of volume visualization, except that it uses spheres rather than
cubes.
This module can be used for non-uniform input fields.
LBL Enhancements resulting from Complete Rewrite
As supplied by Stardent, this module did not process 1D (scatter)
fields. This bug has been fixed. Also, as supplied by Stardent,
there was a bug where "balls" with associated scalar values which
lied outside the range of the colormap were not included in the
output list of balls (on the max value end of the colormap). This
bug has been fixed.
Additionally, the range of the input field would "wrap" around
at 256 in each of the dimensions. The unsigned char responsible
has been changed to an int so this problem went away as well.
In its stock form, the bubbleviz module would generate an output
field, the size of the data portion of the field being four times
as large as that of the input field. This can be problematic
on extremely large datasets. The algorithm has been changed so
that the size of the output field is a function of the number
of entries which have a non-zero opacity, as opacity relates to
sphere size. Thus, spheres of zero radius are not produced.
This is a good method of data reduction in large data sets.
INPUTS
Input Scalar Field (required; scalar field any data)
The input is a scalar field. For irregular fields, any number
of data dimensions are permitted. Only 3D rectilinear and
3D uniform fields are otherwise permitted. Any of byte, float,
int or double data is permitted.
Color Map (required: colormap)
Used to map from scalar values to colors and radius sizes of
the output spheres (from scatter dots). The hsv portions of
the colormap produce the sphere color. The opacity channel
of the colormap corresponds to resultant sphere radius.
PARAMETERS
Opacity Scale
A multiplier factor for the sphere radii. This is particularly
useful for irregular fields, for which the computational-to-
physical mapping often makes the default spheres too small.
OUTPUTS
Data Field (field 1D 3-coord 4-vector real)
The output is a list of points in 3D space, with a 4-vector of
reals at each point: each 4-vector specifies ARGB for the
sphere. The A portion is the radius (ranges from 0 to 1);
the user has the option of attenuating the sphere radius with
the "opacity scale" parameter above.
A typical network using this module looks like this:
GENERATE COLORMAP READ FIELD
| |
+-----------+ +---------------+
| |
NEW BUBBLEVIZ
|
SCATTER DOTS
|
GEOMETRY VIEWER
Note that the list of points generated by the bubbleviz module is
converted to a geometry by the scatter dots module.
RELATED MODULES
Modules that could provide the Data Field input:
read volume
Modules that could be used in place of bubbleviz:
colorizer
gradient shade
Modules that can process bubbleviz output:
scatter dots
HINTS
The final sphere radius size (in the form of geometry produced
by new_scatter_dots) is a product of the opacity function,
the radius scale dial (in this module) and the radius dial
on new_scatter dots.
To produce colored spheres of constant radii, set the radius
scale dial to zero. This will force all spheres, on output
from this module, have a radius of value 0. Then, set the radius
dial in new_scatter_dots to the desired value.
To produce colored spheres of varying radii, set the radius
scale dial to some non-zero value. Then, the resulting radius
value (as computed in new_scatter_dots) will be a product
of:
opacity_function(new_bubbleviz) * radius_scale(new_bubbleviz)
* radius(new_scatter_dots)
AVS Modules new_bubbleviz(6)
Lawrence Berkeley Laboratory 27 Aug 1992