One important factor that needs to be considered for the environment simulation is weather and lighting, since it impacts the way sensors perceive the scene.
When it’s raining outside, the vehicle needs to slow down because the driver’s vision and the road friction have been changed. With the low-standing sun during sunset or sunrise, human driver needs to wear sunglasses because otherwise he/she couldn’t really see the road clearly. Similarly, they also affect sensors like cameras, RADARs, or LiDARs. Fog reduces the visibility of a camera (and absorb energy from a RADAR) and LiDARs are sensitive to rain drops since they scatter the laser beams.
With VTD, engineers can easily create the environments with different weather conditions, like fog, rain, snow, sun glare, at any particular time of the day, whether it’s 6am, 5pm, 10pm and so on.
Sun glare and headlight glare effects
The new post-processing is possible for almost all the camera views with an introduction of glare effects for sun and front headlights. The previous glare effects were of the static size and independent from view direction. In contrast, the new glare effects are now dependent on the view direction and change its intensity and size with the change in camera view direction for the realistic visualization in simulation
Raindrops on windshield and wiping effects
In the physical driving situations, the water trajectories or water film formed on the windshield affects the visibility to the driver, for which mechanical wipers were developed. The same effect of the raindrops needs to be considered in the simulation as well, but the simulation of water droplets on the windshield is a challenging computer-graphics task. However, with the feature “Raindrops on windshield and wiping effects,” it is possible to simulate the raindrops with wiper animation that help for training the drivers and testing the camera in harsh weather conditions