[vtkusers] How to generate a surface normal glyph for a triangle cell

[Elvis Dowson]

Hi,
         I'm just trying to breakdown the problem. I'm just stuck at  
one point below. Could someone help?

arrowGlyphPoints InsertNextPoint [planeSource GetNormal]

I have a plane source and I want to pass the plane normal to an arrow  
glyph. I'm using vtkPoints to represent the location of the arrow  
glyph. I can't seem to get the correct data type to be passed from  
vtkPlanceSource::GetNormal() to vtkPoints::InsertNextPoint() in TCL. I  
get the error message, Object named: arrowGlyphPoints, could not find  
requested method: InsertNextPoint
or the method was called with incorrect arguments.

How can I fix the call to the above method in TCL?

Here are the method declarations.

vtkPoints::InsertPoints(const double x[3])

virtual double* vtkPlaneSource::GetNormal()
virtual void vtkPlaneSource::GetNormal(double data[3])

Question: How can I pass data[3] or double * returned by  
vtkPlaneSource::GetNormal() into vtkPoints::InsertNextPoint() ?

Best regards,

Elvis Dowson


Example TCL code


# This example shows how to manually construct a plane and display its  
surface normal
# using Tcl.
#

package require vtk
package require vtkinteraction

# Create a plane source
vtkPlaneSource planeSource

vtkDataSetMapper planeMapper
   planeMapper SetInput [planeSource GetOutput]

vtkActor planeActor
   planeActor SetMapper planeMapper

# Create an arrow glyph to represent the surface normal
# -----------------------------------------------------

# Specify the location of the glyph
vtkPolyData arrowGlyphPolyData
vtkPoints   arrowGlyphPoints
   arrowGlyphPolyData SetPoints arrowGlyphPoints
   #arrowGlyphPoints InsertNextPoint 1 1 0
   arrowGlyphPoints InsertNextPoint [planeSource GetNormal]

# Specify the shape of the glyph
vtkArrowSource arrowSource

vtkGlyph3D arrowGlyph
   arrowGlyph SetSource [arrowSource GetOutput]
   arrowGlyph SetInput arrowGlyphPolyData

vtkDataSetMapper arrowGlyphMapper
   arrowGlyphMapper SetInputConnection [arrowGlyph GetOutputPort]

vtkActor glyphActor
   glyphActor SetMapper arrowGlyphMapper


# Create the usual rendering stuff.
vtkRenderer ren1
vtkRenderWindow renWin
   renWin AddRenderer ren1
   renWin SetSize 300 150
vtkRenderWindowInteractor iren
   iren SetRenderWindow renWin

#ren1 SetBackground .1 .2 .4

ren1 AddActor planeActor
ren1 AddActor glyphActor

ren1 ResetCamera
ren1 ResetCameraClippingRange

renWin Render

# render the image
#
iren AddObserver UserEvent {wm deiconify .vtkInteract}
iren Initialize
wm withdraw .



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