ameijer
07-13-2003, 02:32 PM
In order to avoid creating gimbal locks, I want to be able to create them, understand them. Problem is I fail abysmally.
The symptoms of gimbal lock as I understand it are that after some rotations around one axis, following rotations about the other two axis look the same or at least inverted. This can only be achieved by letting the latter 2 axis (or is the plural axises?) be parallel.
I read a GameDev article which said that this comes about by using Eulerangles and matrices. Each Eulermatrix rotatates about 1 axis. Rotations about more than 1 axis is achieved by multiplying E-Matrices. Eulermatrices are orthonormal therefore the original orthogonal basis of our coordinate system gets transformed into another orthogonal system after multiplication. And orthogonal systems have no two parallel axis. It is true that there are two (or more) triples of angles that when entered into Euler matrices give the same result, but that was not described as gimbla lock.
If you always rotate about the world coordinate system, gimbal lock cannot appear either as the world coordinate system obviously has no two parallel axis.
The only way to create gimbal lock as I understand it is mixing the two methods of rotation. But mixing the two is like mixing beer and wine and complaining that it tastes bad ( I never tried, have you?).
The symptoms of gimbal lock as I understand it are that after some rotations around one axis, following rotations about the other two axis look the same or at least inverted. This can only be achieved by letting the latter 2 axis (or is the plural axises?) be parallel.
I read a GameDev article which said that this comes about by using Eulerangles and matrices. Each Eulermatrix rotatates about 1 axis. Rotations about more than 1 axis is achieved by multiplying E-Matrices. Eulermatrices are orthonormal therefore the original orthogonal basis of our coordinate system gets transformed into another orthogonal system after multiplication. And orthogonal systems have no two parallel axis. It is true that there are two (or more) triples of angles that when entered into Euler matrices give the same result, but that was not described as gimbla lock.
If you always rotate about the world coordinate system, gimbal lock cannot appear either as the world coordinate system obviously has no two parallel axis.
The only way to create gimbal lock as I understand it is mixing the two methods of rotation. But mixing the two is like mixing beer and wine and complaining that it tastes bad ( I never tried, have you?).