We want to know the world coordinate of a point on a 3D widget event though we don’t know the widget’s position on the world coordinate system. I get a matrix from an actor and create a temporal vtkTransform object, then the function TransformDoublePoint can give me the real coordinate Read more…
notes ${} 和 $[] $[expression] can calculate easily. ${expression} can tell us the value of a element in array. eg val1=23 val2=24 echo $val1+$val2 echo $[$val1+$val2] #it is equal to `echo $(( $val1+$val2 )` [edemon@CentOS workspace]$ ./incalc.sh 23+24 47 assign values to array. array=(`echo {1..10}`) echo ${array[0]}” “${array[9]} [edemon@CentOS workspace]$ Read more…
Some hotkeys of RenderWindowIterator are useful for developers to debug. The content comes from VTKUsersGuide.pdf Keypress j / Keypress t — Toggle between joystick (position sensitive) and trackball (motion sensitive) styles. In joystick style, motion occurs continuously as long as a mouse button is pressed. In trackball style, motion occurs Read more…
The article shows how to clip a cone by a plane. The vtkClipPolyData object provides a major algorithm to process the 3D model. Here is python script that describes all details about it. #!/usr/bin/env python import vtk cone = vtk.vtkConeSource() coneMapper = vtk.vtkPolyDataMapper() coneMapper.SetInputConnection( cone.GetOutputPort() ) coneActor = vtk.vtkActor() coneActor.SetMapper( Read more…
Hallelujah input app is a very powerful tool for Mac user to write words. It can prompt the user to input some individual words that can’t spell. The application also supports to input Chinese words and translate them to English once the user wants to do. I recommend another writing Read more…
vtkRandomGraphSource can be used to create a random graph which includes points and edges. vtkGraphLayoutView is a vtkRenderView which has its own renderer and iterator, we can use it to display graph view. from vtk import * # create a random graph source = vtkRandomGraphSource() source.SetNumberOfVertices(100) source.SetNumberOfEdges(110) source.StartWithTreeOn() #create a Read more…
The article shows how to use python and Mathematica to do elementary arithmetic with a few examples. The examples come from An Elementary Introduction To The Wolfram Language Calculate 10 to the power 12 python: print( 10**12 ) wolfram: 10^12 => 1000000000000 Compute 2 to the power 2 to the Read more…
The article shows how to use a list in python and Mathematica with a few examples. The examples come from An Elementary Introduction To The Wolfram Language Plot a list that counts up from 1 to 10, then down to 1. wolfram: ListPlot[ Join[ Range[10],Reverse[Range[9] ] ] ] python: import Read more…
The airticle shows how to display list in python and mathematica with a few examples. The examples come from An Elementary Introduction To The Wolfram Language Make a bar chart of { 1, 1, 2, 3, 5 } Python: import matplotlib.pyplot as plt y = (1,1,2,3,5) x = range( len(y)+1 Read more…