Move Data Planes Help
This widget allows the user to change the position of the
YZ (i.e., a plane with constant x values), XZ, and XY data planes. It also
allows the user to change the position and orientation of an arbitarily
oriented data plane.
Cutting Plane Resolution
As the view is changing (i.e., not paused) the data planes will be
displayed at the Low resolution specified (thus permitting rapid updates). Once
the view is paused, the data plane resolution automatically will switch to
the High resolution specified. A bigger number corresponds to a lower
resolution. You can lock DAVE into Low or High resolution
(so that it doesn't switch) by mapping a function key to "toggle_highresonly"
or "toggle_lowresonly" - see Configuration Help in the File menu of the Master
widget for more information on this.
NOTE: currently this is a bit buggy and the resolutiond is displayed doesn't
always match the widget's value. Clicking on the widget's value a few times
seems to fix this.
Incr/Decr Cutting Planes
The YZ, XZ, and XY data planes are translated by clicking on the arrows.
Double arrows move more.
Rotate arbitary cutting plane
These arrows permit the user to rotate the arbitarily oriented plane. Thus,
nonorthogonal views through the dataset are possible. The X arrows rotate the
plane around and axis which is parallel to the x axis of the data but which
passes through the center of the arbitrary plane. Similarly for Y and Z. Since
this tends to be a cumbersome way to rotate the plane an alternative
mechanism is provided.
The plane can be rotated by pushing (into the screen) or pulling (out of
the screen) one of 4 "handles" along the edge of the plane. These handles are
labelled A,B,C, and D. The handle which should be pushed or pulled is
specified by choosing the appropriate letter under "Rotation Axis".
Pushing or pulling is accomplished by clicking on the arrows under "Push" or
"Pull". If A is the chosen handle (i.e., axis) the pushing (or pulling) will
rotate the plane as if it was pushed at A (i.e. around an axis parallel to the
side which A is on, but which goes through the center of the plane).
Similarly for B (which goes around a diagonal axis), C, and D.
Currently, sometimes parts of the plane outline will disappear
(be "clipped away") if the outline gets too large. Scaling the image smaller
may help, or it may reappear at different orientations of the scene and/or
the data plane. Let us know if you experience this problem.
Translate arbitary cutting plane
This translates the plane in a direction perpendicular to its surface
orientation (i.e., translates in the "normal" direction).
Orient Arb. Plane
Once the arbitrary data plane has been positioned so that it cuts the
data in the desired location, the entire scene can be rotated so that the
arbitrary data plane is parallel to the screen. This makes it much easier
to view the data plane. Clicking on this button performs this task.
This moves the arbitary data plane back to its initial position. This is
useful if for some reason you get confused about where it is.
As the arbitrary data plane moves, its center moves. When the plane is
rotated it usually rotates about an axis (e.g., A) which goes through its
center. If for some reason you want to fix the "center" so that it does not
necessary correspond to the center of the plane, you can do so by pressing
this button. The "center" will no longer change to correspond to the current
center of the plane (regardless of how you move it). Clicking on this button
again turns the option off (I think). This button was added to deal with
some old problems which no longer exist (I think). I'm not certain about its
current function or reason for existence.
NOTE: You can also see the arbitrary cutting plane "mapped" to a
separate window on the screen (so it is easier to see than looking
at some oblique angle). This is similar to "Orient Arb. Plane" but
puts the image into another window. To do this, map a function key to
"toggle_static_window" and use it to turn on the window. See
Configuration Help in the File
menu of the Master widget for more information on function key
mappings. You can do something similar under Planimeter (Stuff Menu).
NOTE: The arbitarily oriented data plane (when in SURF mode) can take
significant amounts of computer time and memory.
Copyright 1995 by Lawrence M. Lifshitz and the University of
Massachusetts Medical School. All rights reserved.