angles¶
Module: core
Category: vec3dvaluator
Type string: "angles"
Parameters¶
| Name | Description | Default | Units |
|---|---|---|---|
theta |
theta | 0 | [] |
phi |
phi | 90 | [] |
Description¶
This valuator generates a unit vector orientated via the specification of spherical angles (azimuth and declination) relative to the local material axes (or global coordinate system, if no local material axes are defined).
Note that both theta (the azimuth angle) and phi (the declination angle) are defined in degrees.
Figure 1. Illustration for the angles valuator.
The fiber is oriented along
\[
\mathbf{e}_{r}=\cos\theta\sin\phi\,\mathbf{e}_{1}+\sin\theta\sin\phi\,\mathbf{e}_{2}+\cos\phi\,\mathbf{e}_{3},0\leqslant\theta<2\pi,\;0\leqslant\phi\leqslant\pi,
\]
where \(\left\{ \mathbf{e}_{1},\mathbf{e}_{2},\mathbf{e}_{3}\right\}\) are orthonormal vectors representing the local element coordinate system, or global coordinate system.
<fiber type="angles">
<theta>20</center>
<phi>90</phi>
</fiber>