Showing posts with label math. Show all posts
Showing posts with label math. Show all posts

Rotations and lame network cards

It occurred to me while debugging my 3d camera that rotations are far to rotatey. R^T = R^-1 = R(-a) which means if you have a bug it can be confusing and potentially work to some degree even though really your code is completely crazy. In this case I was uploading rotations into opengl that were row major when it is in fact column major. Another amusing thing is if your rotation is several rotations such as R = r(a)r(b)r(c) then R^-1 = r(c)^-1 * r(b)^-1 * r(a)^-1 which means your rotations are now going to be done in a different order in the opposite directions.

I would also like to thank my marvell yukon network card for failing at life. It was trying to offload checksum calcs in vista but doing a worse job than my CPU. So much so that it was causing team fortess 2 to be inoperable. Luckily these things can be adjusted.