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tube_filter(display) Display Classes tube_filter(display)

NAME

tube_filter -- constructs a tube from multiple ribbons.

DESCRIPTION

The tube_filter acts as a front end to the ribbon_filter for constructing tubes from multiple ribbons. When instantiated, it creates private instances of ribbon_filter, append_filter, and merge_filter which it uses to create several ribbons and append them together into a tube. The tube has the number of sides and relative rotation specified by the corresponding instance variables. The tube_filter also accepts (and forwards to its ribbon_filter) any messages relating to offset ribbons.

SUPERCLASS

filter

INSTANCE VARIABLES

num_sides The number of sides of the tube. (Also, the number of ribbons generated for each line in the input data.)

rotation A relative rotation, in degrees, from the default orientation. (The default orientation is the one in which the first ribbon drawn is oriented in the direction of the normal vector.)

scalar_set A collection of sources of scalar data to merge with each ribbon in the tube. The nth member of this collection is used to color the nth side of the tube (with the obvious modulo-wrap-around semantics). A null string as one of the members indicates that the default scalar values from the data_in should be used for that side of the tube.

The following, although actually ribbon_filter instance vari

ables, are useful mainly to users of the tube_filter and can be treated as if they were actually tube_filter instance variables.

stretch_factor The factor by which to stretch the tube in the stretch_direction (see stretch_angle below). A non- unity value causes the tube's cross section to become more "elliptical". The default value is 1.0.

stretch_angle Indicates the direction, via angle relative to the normal, in which to stretch the cross section of the tube by the stretch_factor.

MESSAGES

generate_data! Generates the proper data and sends it to the display_data object indicated by data_out.

num_sides[=+?] Set, increment, or query the number of sides of the tube.

rotation[=+?] Set, increment, or query the relative rotation of the tube.

scalar_set[=+-?] Standard collection messages.

othermessages Any message related to offset ribbons is forwarded directly to its ribbon rilter.

EXAMPLE

grid_deometry new:case1_geo data_in=case1_gridset01 extent=(15,15,1,18,1,16);

contour_filter new:cf range=(.01,.03) data_in=case1_geo num_divisions=10;

tube_filter new:rf num_sides=5; start_radius=1.0; vary_radius_inverse!; data_in=cf;

surface new:surf1 data_in=rf;