Shadows

Chosing an apppropriate shadow technique is a flip side of lighting implementation that cannot be disregarded if aiming for achieving graphic realism. The percieved scene substantially benefits from adding the shadows, as they provide the visual cues to the distance between the objects and their spatial relationships. In addition to that, shadows also allow to infer the physical shape of the objects, that block the light, and shadow-recieving surface, thus enriching the relief of the scene-represented geometry. And of course they hint where and of what form the light source is.

Unigine offers the following techniques for visualizing shadows:

• The basic Shadow Mapping
• The enhanced Parallel-Split Shadow Mapping

The importance of lighting for the scene perception was already dwelt upon in the corresponding articles. The following checkboxes define the shadowing by and of the surface:

• Cast shadows — the surface will cast shadows if lit by any of the light sources, except for the world lights.
• Receive shadows — the surface will be shadowed, if between it and the light source appears the casting-shadow obstacle. This also concerns any sources, except for the world lights.
• Cast world shadows — the surface will cast shadows from the world lights. This option is separated, as this type of sources use a different shadowing technique (PSSM).
• Receive world shadows — the surface will be shadowed, if the incident world light will be occluded by some casting-shadow obstacle.

Split