Rotation representation: Matrix
\(
\left\{
\begin{array}{l}
\mathrm{R}=
\left(
\begin{array}{ccc}
r_{00} & r_{01} & r_{02} \\
r_{10} & r_{11} & r_{12} \\
r_{20} & r_{21} & r_{22} \\
\end{array}
\right) \\ \\
\mathrm{R}^T\,\mathrm{R}= \mathrm{Id}
\end{array}
\right.
\)
Pro.
-
- Standard structure (storage,manipulate)
-
- Simple application to vector: \(v'=\mathrm{R}v\)
-
- Composition b/w rotations: \(\mathrm{R} = \mathrm{R}_1\,\mathrm{R}_2\)
Cons.
-
- Large redundancy (9 coefficients for 3 dof).
-
- Rotation parameters don't appear explicitely
-
- Unclear interpolation
-
-
- Linear interpolation doesn't work well for large angles
-
ex. \(\mathrm{M}=(1-\alpha)\,\mathrm{R_1}+\alpha \mathrm{R}_2\)
-
=> \(\mathrm{M}\) is not a rotation anymore (not a vectorial space)
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