Bias Shadow Mapping Evolution

Here are some screen captures of the program when I was computing Bias Shadow Mapping

(based on http://www.opengl-tutorial.org/intermediate-tutorials/tutorial-16-shadow-mapping/ )

First implementation :

We can see there is a shadow acne problem when we don't add the bias. 

Resolved when we add a bias (small error margin).

We also get confronted to peter panning problem (Flying shadows)

Final implementation : 

And to solve this problem we figured out (With the help of the tutorial given above) that with strong object. (Larger than one pixel this problem is resolved and it's more realistic to have a larger wall)