GEOMETRY commands


PROGRAM NAME

gextents - Generate Geometry Representing Extents Around Data

DESCRIPTION

The gextents module is used to create a geometry object depicting the bounds of the space occupied in R3 of the input data.

If present, the location segment of the input data must be in R3 (i.e., have X, Y and Z components), while the value portion of the input data may be of an arbitrary dimension. In the instance when input data is provided which has no location segment, the coordinates used are the indeces into the (w,h,d) portion of the value segment. In other words, if the input data set has a value segment of size width=32, height=48, depth=24, elements=3, and time=N, and no location data is present, the resulting box would have it's two corners positioned at (0,0,0) and (31,47,23).

Two different box types may be selected by the user. The first type always results in a rectangular shaped box, regardless of the location data. This box type is called a "min/max" box. The maximum extents of the location (either from the explicit location data or from the scheme outlined above) of the data are computed, and a box is constructed with two corners at those locations. The other box type may result in a non-rectangular box, depending upon the behavior of the explicit location data.

The user may elect to have a "colored" box or a white box. If we consider the three dimensions of the data to correspond to the logical variables (u,v,w), then the box will be colored so that red lines indicate constant (v,w); green lines indicate constant (u,w) and cyan lines indicate constant (u,v).

The user also has the option to show the "sides" of the box as grids, by setting one or more of the "axis Min" and "axis Max" toggles to True. For example, setting Vaxis Min to True would display the side of the box where v = 0. While viewing the sides of the box, it may be helpful to set the "Show Bounding Box" toggle to False, which will remove the overall bounding box and show only the geometry for the sides that are currently selected.

Additionally, the user may provide an explicit name (text string) for the resulting geometry object. This name may be available to assist in object identification and manipulation in a downstream renderer, depending upon which one is being used.

REQUIRED ARGUMENTS

-i
type: infile
desc: input data object
-o
type: outfile
desc: output geometry object
-show_bounds
type: boolean
desc: If true (default), will display the wireframe bounding box of the object.

OPTIONAL ARGUMENTS

-color
type: integer toggle
desc: If 1, the lines will be colored white, else they will use the red, green, cyan color scheme described above
default: 2
allowed values:
-type
type: integer toggle
desc: Select between one of the two box types
default: 2
allowed values:
-name
type: string
desc: The name selected here will identify the extents object in the renderer
default: extents box
-u_min
type: boolean
desc: If true, will cause a two D wire mesh object to be built at u=0.
default: false
-u_max
type: boolean
desc: If true, will cause a 2d wire mesh object at u=umax to be build.
default: false
-v_min
type: boolean
desc: If true, will cause a 2d wire mesh object at v=0 to be built.
default: false
-v_max
type: boolean
desc: If true, will cause a 2d wire mesh object at v=1 to be built.
default: false
-w_min
type: boolean
desc: If true, will case a 2d wire mesh object to be built at W=0.
default: false
-w_max
type: boolean
desc: If true, will cause a 2d wire mesh object to be built at w=1.
default: false
-lod
type: list
desc: Controls how much detail is produced. This variable provides control over the amount of geometry gneerated.
default: 1 "Fine"

EXAMPLES

SEE ALSO

RESTRICTIONS

REFERENCES

COPYRIGHT

Copyright (C) 1996,1997 , The Regents of the University of California. All rights reserved.