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incorrect Inverse function in sampleMath class

By de_duu on Thu, 04/18/2013 - 16:51

Hi, I just found out that Inverse function in SampleMath class was incorrect.

Does anyone have corrected version?

it seems that I did not get identity matrix after multiplying the matrix with it's inverse.. Thanks

incorrect Inverse function in sampleMath class

Can you post a snippet of the code that you're using?

incorrect Inverse function in sampleMath class



 for(int tIdx = 0; tIdx < state.getNumTrackableResults(); tIdx++)
    {
        // Get the trackable object from getTrackableResult()
        const QCAR::TrackableResult* result = state.getTrackableResult(tIdx);
        const QCAR::Trackable& trackable = result->

incorrect Inverse function in sampleMath class

Hi de_duu,

indeed, our sample code for inverse matrix calculation actually returns the "inverse transpose" matrix, instead of just the pure "inverse";

incorrect Inverse function in sampleMath class

Hi AlesandroB,

Indeed, I got the inverse result by transpose again the matrix. Here I want to calculate the coordinate of one target relative to another. I understand how to calculate theoretically, but I got wrong results in implementation.

incorrect Inverse function in sampleMath class

Hi,

if you are trying to compute the position of a target with respect to another, I would recommend to read this tutorial:

incorrect Inverse function in sampleMath class

Hi AlesandroB,

Thanks for your recomendation. However, do you have any clue to get the rotation matrix also?

Thanks

incorrect Inverse function in sampleMath class

Hi,

I just realise that obtaining the rotation matrix is a trivial task. I have successfully got the relative transformation matrix between two trackables.

incorrect Inverse function in sampleMath class

Hi, the relative transformation of one target with respect to another indeed should not change (if correctly computed); however, some little variations may be expected, due to the tracking precision, as you say.