[IGSTK-Users] Multiple tracking systems

[Patrick Cheng]

Hi Alberto,

When I said "add spatial object to view", I meant "spatial object 
representation". Sorry for the confusion.

Your scene graph connection should work. You can check your scene graph 
tree construction by enabling the IGSTK_USE_SceneGraphVisualization in 
CMake, and use the following code after you making the scene graph tree 
connection.

You can either output the graph to a dot file, or display it on the fly 
in a FLTK GUI.

   // Output to file
   igstk::SceneGraph * sg = igstk::SceneGraph::getInstance();
   sg->ExportSceneGraphToDot("sg.dot");

   // Display it in a window. You need to include igstkSceneGraphUI.h
   sg->ShowSceneGraph(true);
   igstk::SceneGraphUI * sgUI = igstk::SceneGraphUI::getInstance();
   sgUI->DrawSceneGraph(sg);


Patrick

alberto.vaccarella at mail.polimi.it wrote:
> Hi Patrick,
> 
> I'm trying to add also the spatial objects to the view3D as you 
> suggested, but the RequestAddObject() method seems to accept only 
> spatial object representation pointer as parameter...
> About the scene graph, I connected both the view3D and the optical 
> tracker controller to an axes object acting as a world coordinate 
> system, shouldn't this work?
> Thanks for helping
> 
> Alberto
> 
> 
> 
> 
> 
> 
> Citando Patrick Cheng <cheng at isis.georgetown.edu>:
> 
>> 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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> 
> 
> 
> 
>