Emitters

The Eradiate kernel provides a custom astronomical object emitter to model solar and celestial radiation sources. It is designed to simulate top-of-atmosphere boundary conditions where the illumination source subtends a finite solid angle.

Distant astronomical object (astroobject)

Parameter	Type	Description	Flags
irradiance	spectrum	Spectral irradiance, which corresponds to the amount of spectral power per unit area received by a hypothetical surface normal to the specified direction.	P, ∂
to_world	transform	Emitter-to-world transformation matrix.	P
direction	vector	Alternative (and exclusive) to to_world. Direction in which the emitter is visible in world coordinates.	—
angular_diameter	float	Angular diameter of the object in degrees. (Default: 0.5358)	—

This emitter plugin implements an environment light source simulating a distant astronomical object. It radiates a specified power per unit area within a solid angle specified by the angular_diameter parameter. By default, the emitter radiates in the direction of the positive Z axis, i.e. \((0, 0, 1)\), with an angular diameter equal to the average apparent size of the Sun from Earth.