illumination

Defined in: eclipse.rs:66

fn illumination(observer_pos: &nalgebra::Vector3<f64>, light_pos: &nalgebra::Vector3<f64>, occulter_pos: &nalgebra::Vector3<f64>, light_radius: f64, occulter_radius: f64, model: ShadowModel) -> f64

Compute the illumination fraction at observer_pos.

All positions must be in the same coordinate frame and units (km).

Returns a value in [0.0, 1.0]:

• 1.0 = fully sunlit (no eclipse)
• 0.0 = total eclipse (umbra)
• intermediate = partial eclipse (penumbra or annular)

Arguments

• observer_pos — position of the observer (e.g. satellite)
• light_pos — position of the light source (e.g. Sun)
• occulter_pos — position of the occulting body (e.g. Earth)
• light_radius — radius of the light source [km]
• occulter_radius — radius of the occulting body [km]
• model — shadow model to use