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.

Init Position

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.

Fix Center

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.