Features
Fake Volume
We want our street lights to illuminate not only the floor but also the dust particles in the air.
Since volumes are too expensive, we decided to implement a fake volume using a semi-transparent cone. The cone was setup in such a way that it does not capture those.
L-System
We want our trees to match the natural beauty as best as possible.
Since modelling them by hand is a tedious process, we decided to use the grammar-based approach originally suggested by Aristid Lindenmayer. A paper by Sun et al. [3] made it accesible to us and inspired us.
Cloth Shader
We want the snowman's hat to look realistic.
In the original Blender model, we used the Velvet shader, which is commonly used to model cloth. After researching on how to reimplement this in our raytracer, we ended up with the Ashikhmin BRDF described in [1] and [2].
Moreover, we implemented randomly generated snow and the depth of field effect.