In general, Approximated lighting mode requires all parts of the beam to hit a single plane to stop the beam from passing through objects. However, sometimes the light beam passes through an object even though all parts of the beam hit the single object if it is coming from an oblique angle.
Explanation of Issue
The light range of the beam is determined by the longest distance required to fully illuminate the surface completely.
The beam of light in Approximated lighting mode is always an isosceles cone, which means that edges of the cone are always the same length. Depending on the angle, this can cause parts of the beam to extend past the target surface.
If another surface/object is in the range of the cone as it extends through the surface, that item will also be illuminated.
- Use Realistic lighting mode to avoid this behaviour.