As every cyclist knows, not every ride is under beautiful blue skies. I therefore felt it necessary to create a simple weather system. Whilst it's in the test-bed, the weather system simply cycles between sunny and stormy over a set period. I've written the system so that it can be triggered at any point in time, or at any point on the stage. For instance, you might want the rain to come in after the first mountain climb.
The weather system currently consists of 2 layers of fog (blended in over time) and a particle system for the raindrops.
There is a fog layer between the clouds layer and landscape. This is only used to darken the clouds as the storm rolls in. There is another (more subtle) fog layer over the entire screen. This is used to create a mist layer to 'grey out' the scene.
The raindrops fall and create splash effects upon hitting a surface (eg. rooftops and roads). It's tricky to make out the splash effect from the screenshot, but looks good moving. I have also created a simple lightning effect triggering a full screen 'white-out'.
It is intended that the weather system will affect gameplay; examples could be rider fatigue, puncture frequency, tyre choice etc
Sunny:
Stormy: