== A 3D Drawing Widget for Rappture ==

This widget can be used for both Rappture inputs and outputs.  It displays a drawing in 3 dimensions. It is *not* a 3D drawing editor.   A goal is to replace images of specimens or devices with a 3D drawing that can be manipulated.  

{{{
<drawing>
  <about>
    <label>...</label>
    <description>...</description>
  </about>
  <xaxis>
    <label>...</label>
    <units>...</units>
  </xaxis>
  <yaxis>
    <label>...</label>
    <units>...</units>
  </yaxis>
  <zaxis>
    <label>...</label>
    <units>...</units>
  </zaxis>
  <polydata>
    <about>
      <label>Polydata Example</label>
      <style>-color blue -opacity 0.9 -linewidth 2</style>
    </about>
    <vtk>..vtk file contents..</vtk>
  </polydata>
  <glyphs>
    <about>
      <label>Glyphs Example</label>
      <shape>sphere</shape>
      <style>-edges off -gscale 1</style>
    </about>
    <vtk>..vtk file contents..</vtk>
  </glyphs>
  <molecule>
    <about>
      <label>Molecule Example</label>
    </about>
    <pdb>..pdb file contents..</pdb>
  </molecule>
</drawing>
}}}    

 * Purposes:
   * A simple device viewer.  Can be rotated and zoomed.  
   * Lets you build a structure with several layers.  
   * View simple molecules.
 * Axes are optional.
 * Components are basic geometric types or vtk file types.
 * Individual components can be hidden.
 * Associations can be made between components/values and another Rappture input.
   * A notification is generated whenever the input changes, causing the drawing to be rendered with the new values.
 * Right now software rendering is done on the execution host.  Can create client/server application on render servers.
   * This works so long as number of objects is manageable (not 1 million atoms).

 * Needs:
   * Examples of inputs and outputs.
     * Types of interactions with inputs.
     * Types of interactions with outputs.