[tuhopuu-devel] 3D digitizer support for Blender?

[Jonathan Merritt]

Hello Everyone,

I am working on a project for which I would like to add support for a 3D 
digitizing arm to tuhopuu.  I should probably first explain what these 
wonderful little gizmos are, since many people will probably not have 
been lucky enough to have had the chance to play with one...  Basically, 
a 3D digitizing arm is a kind of input device, used almost exclusively 
to capture points in real space for use in measurement, modeling, 
reverse engineering, quality assurance, etc.  Faro and Microscribe are 
the two manufacturers supported out-of-the-box by Rhino3D (which is what 
I'm using when I'd like to be using Blender!) - you can find both of 
them online.

In my specific application, I am digitizing bones.  I would like to have 
the ability within edit mode for a mesh to:
    1. Move the digitizer around and view its tip position as the 
position of the 3D cursor.
    2. Add points when I click the digitzer's button. 

One option I would like to propose is a plugin type arrangement, where 
different digitizer plugins can be registered with the GHOST system.  
Different digitizers will implement a common interface that can be 
expected to be within the capabilities of all models (eg: query of probe 
location, registering of button events, etc.).  Ideally, the plugins 
will be loadable at run-time, so that all of the hardware- and 
platform-specific code required can be maintained separately from 
Blender itself.

An alternative to this (which I see as much more practical) is to add 
support for a digitizer using a Python script.  For my own application, 
this seems the easier option, since the necessary mesh editing and 3D 
cursor positioning methods are already available from Python.  However, 
I think that eventually a standard interface to a digitizer from within 
Blender itself could be very useful.

I will be proceeding with the Python script option myself, and will 
contribute a script to add points to a mesh in edit mode using a FaroArm 
digitizer.  I'm very interested in hearing what people think of the 
"built-in" option though.

Jonathan Merritt.