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Member Since 08 Aug 2012
Offline Last Active Aug 21 2013 04:33 PM

Posts I've Made

In Topic: Is the concatenation of a VQS with its inverse commutative?

23 June 2013 - 01:58 AM



Solution was to ensure all quaternions were normalized, thus representing rotations.

In Topic: Is the concatenation of a VQS with its inverse commutative?

22 June 2013 - 11:26 PM

Ok good idea. Here's an example that might help. Incidentally, the issue it seems appears to be with the Inverse(VQS) function. Here's a test case:


T = [(-3.2, 1.6, -10.3) , (-0.52, 0.68, 0.49, 0.32) , 2]


Inverse( Inverse(T) ) = [(-4.0, 2.5, -9.9) , (-0.52, 0.68, 0.49, 0.32) , 2]


Inverse( Inverse(T) ) should return T. The scalar and quaternion components are correct, however the translation vector is off. It looks like the method to find the inverse translation component might be incorrect.

In Topic: World to Camera Transformation using Quaternions

12 January 2013 - 01:59 PM

Yes you're right! Also it seems like more work to use Quaternions for the final World to Camera transform. I might just stick with matrices.

In Topic: Triangle rasterization troubles

04 January 2013 - 10:51 PM

Thanks guys. After much experimentation, the problem was with rounding errors. I have since switch to using a fixed point number representation for greater accuracy and have solved the issue, pretty much as AB suggested.


Also, Krypt0n you migh be right about the error introduced by incrementing xs and xe each iteration, I'll check it out.

In Topic: Q: Fast and simple way to store/manipulate pixels?

12 August 2012 - 06:01 PM

Ok thanks, I think
will prove useful. Also I think you're righ eppo. Working with UCHAR data seems to have a few limitations.