Graphics Reference
In-Depth Information
Extracting the angle and axis of rotation from a transform
⎡
⎤
a
11
a
12
a
13
⎣
⎦
R
α,
v
=
a
21
a
22
a
23
a
31
a
32
a
33
α
=
arccos
((
Tr
(
R
α,
v
)
−
1
)/
2
)
v
=
v
1
i
+
v
2
j
+
v
3
k
v
1
=
(a
22
−
1
)(a
33
−
1
)
−
a
23
a
32
v
2
=
(a
33
−
1
)(a
11
−
1
)
−
a
31
a
13
v
3
=
(a
11
−
1
)(a
22
−
1
)
−
a
12
a
21
.
