3D Plane Definition Menu

When the Contour Definition Menu is spawned specifing one of the plot axes to be a function of Contour, the Method option in the Contour Definition Menu is enabled. Selecting RANDOM(3D) as the Method creates one instance of the 3D Plane Definition Menu. The menu is created silently that is it does not pop immediately up onto the screen but is added to the Menu List in the lower section of the Control Panel and from there can be brought into the foreground needed.

This menu contains all the options needed to define a plane through a 3D data set onto which a contour will be projected. A contour mesh is placed on the plane and the values at the mesh points interpolated through a 3D least squares fit using the nearest data points. The base plane is defined to contain the origin of the data (0, 0, 0) and to have a normal vector which is defined in the menu. The base plane can then be translated in either direction along the plane normal.

The menu can also be used to set up a sequence of steps though which the defined contour plane can be rotated and/or translated. A contour is produced at each step allowing for the data to be viewed at a number of cuts.

The menu has the appearance: 










Top Section Menu Options






CLOSE


CLOSE closes the 3D Plane Definition Menu window.





Main Section Menu Options






Normal Vector Source


NORMAL VECTOR SOURCE defines the how the vector normal to the
contour plane is to be defined. The options are:













 Option Definition

 USER
     The user must enter the normal vector in the 
                      VECTOR DEFINITION entry boxes on next option line.

 UDF
     The Normal Vector is derived from a UDF source.  
                      Selecting this option will pop up one instance of the 
                      Vector Source Menu. 






Vector Definition


VECTOR DEFINITION is enabled only if the Normal 
Vector Source  option has been set to USER.  The normal vector
is specified by giving the two spherical angles defining the vector.  The
first entry box is for the phi angle (angle in the XY plane) and
the second entry box is for the polar or elevation angle (angle measured
from the XY plane with positive angles used in advancing toward +Z and
negative angle used in advancing toward -Z).



Initial Rho


INITIAL RHO specifies a rotation angle about the normal vector.
This allows the contour plane to be rotated about normal.  If the
rotation is to occur in steps then this is the beginning rotation
angle in the sequence.



Initial Translation


INITIAL TRANSLATION specifies the distance to translate the contour 
place along the normal.  A positive translation is in the direction of the 
normal vector.  If the translation is to occur in steps then this is the 
beginning translation in the sequence.



Number Of Steps



NUMBER OF STEPS specifies the number of steps to use in taking
the contour plane from an initial orientation to a final orientation.
A contour of the data is produced at each step.  If no steps are required 
(the initial contour place definition is the only required plot) then the 
value is set to 1.  The option is useful to see a distribution at a number 
of cuts.



Contour Plane Rotation



CONTOUR PLANE ROTATION defines the final orientation of the contour 
plane X axis.  Once the base contour plane has been established,  the
normal to that place becomes the new +Z axis and the XY axis establishes
the plane.  With this option the X axis of the base contour plane can
be rotated to any of the other prime axes.  This is done by recomputing
the normal.  As an example, if the X axis of the base plane is rotated to 
the +Z axis (the plane normal) then the contour plane would be the
YZ plane in the base coordinate system.









 Option Definition

 X Axis
     Default condition - no rotation occurs.

 Y Axis
     Rotate the X contour plane axis to the Y contour
                      plane axis.

 Z Axis
     Rotate the X contour plane axis to normal vector 

 -X Axis
     Rotate the X contour plane axis to the -X contour
                      plane axis.

 -Y Axis
     Rotate the X contour plane axis to the -Y contour
                      plane axis.

 -Z Axis
     Rotate the X contour plane axis to lie opposite
                      the normal vector 







Rotation Steps


ROTATION STEPS is enabled only if the Number Of 
Steps option is greater than 1.  The three entry boxes specify the 
rotation step sizes of Phi, Theta and Rho angles
to take in each orientation step of the contour plane.
All values are in degrees.



Translation Steps


TRANSLATION STEPS is enabled if the Number Of 
Steps option is greater than 1.  It specifies the translation step size 
to use in each orientation of the contour plane.  The value is given in 
terms of the data units along the X and Y axes.




Option Effects



The following examples show the effects of some of the options available 
through the 3D Plane Definition Menu.  



Normal and Translation Options

A set of 3D electron data is plotted using a 
3D Contour.  The plane on which the data is rendered is established 
by using the local magnetic field as the plane normal.  
and then then translated along the normal.  The menus 
which establish this are:























The resultant plot to which a set of 1D Cuts has be added and with the
parameters defining the contour plane given above the plot is:










Stepping Option

The contour plane is translated from -5000 km/sec to 5000 km/sec in 
25 steps.  Each step is 500 km/sec.  A contour plot
is output at each step.









All 25 plots are output on a single page as: