title: simple graph visualisation with coloring via paraview using vtk
body: <p>I want to visualize some graph in paraview: a bunch of points with coordinates with a bunch of edges between them. I also want to color points and edges lines. I think this is not something hard to do with vtk format since i found that vtk format examples have almost something that i needed.</p>
  
  <p>As i understand paraview uses point data to assign some scalar value to the point, and color lookup table to bind correspondence between scalar values and colors. But i barely can understand something from a description of lookup tables how to declare this.
  I've started with some modifications on vtk example of cube:</p>
  
  <pre><code># vtk DataFile Version 2.0
  Cube example
  ASCII
  DATASET POLYDATA
  POINTS 8 float
  -1.0 -1.0 -1.0
  1.0 -1.0 -1.0
  1.0 1.0 -1.0
  -1.0 1.0 -1.0
  -1.0 -1.0 1.0
  1.0 -1.0 1.0
  1.0 1.0 1.0
  -1.0 1.0 1.0
  LINES 12 36
  2 0 1
  2 0 3
  2 0 4
  2 1 2
  2 1 5
  2 2 6
  2 2 3
  2 3 7
  2 4 7
  2 4 5
  2 5 6
  2 6 7
  
  POINT_DATA 8
  SCALARS sample_scalars float 1
  LOOKUP_TABLE my_table
  0.0
  1.0
  2.0
  3.0
  4.0
  5.0
  6.0
  7.0
  LOOKUP_TABLE my_table 8
  0.0 0.0 0.0 1.0
  1.0 0.0 0.0 1.0
  0.0 1.0 0.0 1.0
  1.0 1.0 0.0 1.0
  0.0 0.0 1.0 1.0
  1.0 0.0 1.0 1.0
  0.0 1.0 1.0 1.0
  1.0 1.0 1.0 1.0
  </code></pre>
  
  <p>0) I really don't understand how coloring was performed on the result visualization. ( <a href="http://i49.tinypic.com/igksqa.png" rel="nofollow">http://i49.tinypic.com/igksqa.png</a> ) . How does the numbers in this file corresponds to this coloring?</p>
  
  <p>What i want to modify:</p>
  
  <p>1) How can i implement visible points. In this vtk file points are just anchors for the lines and are not visible. I want to display them as well and be able to vary their size in paraview just like line width could be modified (Display -> Style -> Point size). Also i want those points to be colored as well.</p>
  
  <p>2) Can i somehow be able to turn on\off come colors. Let's say i have 5 colors and i want to be able to display only nodes\edges with one of the color. If i understand correctly, this could be achieved using several scalar tables, where each scalar table has colors with opacity = 0 for those nodes\edges which i do not want to display.</p>
  
  <p>3) Am i right that lines couldn't be referenced directly and they are colored only using the two points' data ?</p>