The Shadow light object can render real-time shadows from other objects with the Shadow caster behavior.
The Shadow light object renders shadows adjacent to objects with the Shadow caster behavior, using the object's collision polygon and the relative location of the light. Shadows are filled in over the background, as opposed to rendering sections of light. The Z order of the Shadow light object determines whether the shadows appear above or below other objects.
The light can be set to have a radius. If the radius is 0, it acts like a point source, and shadows have hard edges. If the radius is larger, it accurately renders penumbras (the transition from lightness to darkness) at the edges of shadows. However in this mode the light height is ignored and all shadows extend off the screen.
Due to the shadow rendering algorithm, there are a couple of limitations:
By default, all shadow lights cast shadows off all shadow casters. In some cases it is desirable to only have certain shadow lights cast shadows off certain shadow caster objects. Each shadow light object can be assigned a tag, and the Cast from property set to only cast shadows from that object off shadow caster behaviors with the same (or different) tags.
The Shadow light object does not have any of its own conditions.