When you classify rendering techniques by the number of pixels they will impact in the final image. ShadowMapping is one of those features that have a non negligible effect on the overall realism of your scene.
But having a working shadowMap is one of the most trickiest problem I have found so far. In your journey across the shallow lands of depthExtraction you will find at least 4 different types of artifacts and each one of them is going to ruin your final rendering.
For each one you will encounter dozen of papers or so called shadow prophets which will …