I want to develop a component for 3d shadow analysis of 3d city model. I decided to use ray tracing for this purpose. For every time step (for sun's dynamic position during the year) rays will be sent from sun (point light source) and with ray intersection tests surfaces which are and how long are in shadow will be determined. Are there any components for this purpose such as sun's position, ray tracing etc. or do I have to code everything from beginning to the end? Any answer would be very helpful.
I use Nvidia OptiX for Ray casting and tracing purposes. It is based on CUDA and gives you a library that runs on GPU and is capable of building and traversing efficient acceleration structures. You just supply a few programs such as intersection tests and shading and OptiX does the rest. I personally think it is really easy to work with it but your milage may vary. With this it should be very doable to make your project and even with decent running speed.