Add incident wave arrow setting for waterfall scene.
This function visualizes the incident wave arrows for waterfall settings.
- Parameters:
- phi_span
float Incident phi angle in degrees.
- num_phi
int Number of phi points.
- arrow_color
str, optional Color of the arrow. The default is red ("#ff0000").
- line_color
str, optional Color of the line. The default is red ("#ff0000").