[IGSTK-Users] Multiple tracking systems

[Patrick Cheng]

Hi Alberto,

Your approach is quite novel. Normally people think about register EM 
and Optical trackers together first, now you are tracking the EM tracker 
using Optical tracker.

1. One quick question:
Did you calibrate the EM FieldGenerator with the opticalTrackerTool(0)?
opticalTrackerTool(0) --> FieldGeneratorBoxObject

You need to have this transform set properly to get the accurate 
position of the EM sensor in the optical tracker space.

2. To answer your question about what should be added to View3D.
    You need to add also the spatial objects into View3D so it can 
render it.
    You also need to connect your View3D to the scene graph tree, so it 
knows where to render those objects. In this case, you should try:

View3D --> opticalTracker --> opticalTrackerTool(0) --> 
FieldGeneratorBoxObject --> magneticTracker --> magneticTrackerTool --> 
EM_Sensor_CylinderObject

Hope this helps,

Patrick


alberto.vaccarella at mail.polimi.it wrote:
> Hi everyone,
> 
> I'm trying to develop an application using both an optoelectronic and a 
> magnetic tracking system, the setup is as follows:
> 
> - the optoelectronic device tracks some tools and the EM field generator
> 
> - the magnetic device tracks one sensor with respect to the coordinate 
> system of its EM field generator
> 
> I want all the tools and the EM sensor to be displayed in the same 
> coordinate system (the optical device one); to do that I:
> 
> - instantiated 2 tracker controllers
> - built the scene graph as follows (after the tracking has started ):
> 
> opticalTracker --> opticalTrackerTool(0) --> FieldGeneratorBoxObject --> 
> magneticTracker --> magneticTrackerTool --> EM_Sensor_CylinderObject
> 
> where:
> - opticalTrackerTool(0) is the rigid body associated to the EM field 
> generator
> 
> Is this approach correct? What should I add to the view3D? I added the 
> representations of the two objects but it doesn't work, it doesn't 
> display anything...
> Once I solve this I guess I have to use:
> 
>       EM_Sensor_CylinderObject->RequestComputeTransformTo(opticalTracker)
> 
> I'm not sure I got how to use this method...should I call it once or 
> each time I need the transform? How could I make the 
> EM_Sensor_CylinderObject to be always displayed in the opticalTracker 
> coordinate system?
> 
> Thanks in advance for any help
> Alberto
> 
> 
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