vtkHEDGEHOG Procedure
Creates a HedgeHog (vector) plot.
Usage
vtkHEDGEHOG, points, vectors, scalars
Input Parameters
points—A 3, n array of points (location of the lines).
vectors—A 3, n array of vectors (orientation and length of the lines).
scalars—(optional) An n-element array of scalars (colors of the lines).
Keywords
Scalefactor—A float, a scaling factor to control the size of the oriented lines of the HedgeHog object (Default: 1.0).
SRange—A two-element integer array, the scalar range (Default: [0,255]).
LOD—If nonzero, a level-of-detail actor is created to aid in keeping a high frame-rate during frequent render requests due to user mouse interaction. If set to a value greater than 1, the number of points to use in the random cloud.
NoRotate—Does not perform any camera rotations. Used when a previous call to vtkSURFACE, vtkSCATTER or vtkPOLYSHADE has already set the camera angle.
NoAxes—If set, no axes are created.
NoErase—If nonzero, prevents the window from being erased to the background color before drawing the new scene. If not set, then all lights, cameras, and objects are removed from the scene before objects for the new scene are added.
The following keywords are passed to vtkAXES. Refer to vtkAXES Procedure for descriptions.
 
Example
This example plots a Hanning surface and its normals.
LOADCT, 2
n = 50
x = REBIN(INDGEN(n),n,n)
y = TRANSPOSE(x)
z = (n/2)*(HANNING(n,n))
norm = NORMALS(JACOBIAN(LIST(x,y,z)))
;
points = FLTARR(3,n*n,/NoZero)
points(0,*) = x(*)
points(1,*) = y(*)
points(2,*) = z(*)
vectors = FLTARR(3,n*n,/NoZero)
vectors(0,*) = (norm(0))(*)*SQRT(z(*))
vectors(1,*) = (norm(1))(*)*SQRT(z(*))
vectors(2,*) = (norm(2))(*)*SQRT(z(*))
scalars = z(*)
;
vtkHedgeHog, points, vectors, scalars, /NoAxes, scalef=0.75
vtkSurface, REFORM(points(2,*),n,n), $
   Shades=REBIN([0.8,0.8,0.8,.75],4,n,n), $
   /NoErase, /NoRotate, /NoAxes
See Also