Graphics Reference
In-Depth Information
Y
X
′
yaw
= 90
Y
′
Z
X
Z
′
Fig. 7.11.
The
X
Y
Z
axial system after a
yaw
of 90
◦
.
Y
Y
′
X
′
roll
=45
Z
′
Z
X
Fig. 7.12.
The
X
Y
Z
axial system after a
roll
of 45
◦
.
Y
pitch
= 90
Y
′
X
′
Z
X
Z
′
Fig. 7.13.
The
X
Y
Z
axial system after a
pitch
of 90
◦
.
a yaw of 45
◦
about the
z
-axis, it would rotate the x
-axis towards the
x
-axis,
counteracting the effect of the original roll. yaw has become a negative roll
rotation, caused by the 90
◦
pitch. This situation is known as
gimbal lock
,be-
cause one degree of rotational freedom has been lost. Quite innocently, we
have stumbled across one of the major weaknesses of Euler angles: under cer-
tain conditions it is only possible to rotate an object about two axes. One
way of preventing this is to create a secondary set of axes constructed from
three orthogonal vectors that are also rotated alongside an object or virtual