I'm relatively new to Cesium and have taken a look at the documentary as well as the source code of the software. The ShadowMap seems to handle the calculation of shadows in relation to the sun as a light source.
I'm actually quite surprised that Cesium is able to display shadows with relative high accuracy in real time even for large models (e.g. city maps). I have a couple of questions about that because the source code is pretty complex and hard to understand if you are not familiar with the entire basics.
1) What algorithm is used to calculate the shadows?
2) Are all the calculations done in real time or are they pre-processed and then loaded into the application at launch or when required?
3) Does the 3D model itself hold any information about which parts are covered by shadow or is the shadow a texture with no actual ties to the model itself?
Thanks in advance for any replies.