The H: Some individuals and organisations have even re-packaged FlightGear and tried to resell it as a commercial product (Flight Pro Sim, Pro Flight Simulator, etc). What did the project do when these were discovered?
CO: I don't want to spend too much time on a negative topic. There will always be a few selfish people in the world that will say or do just about anything to make a buck. As far as the FlightGear team can determine, these "Flight Pro Sim" guys are technically (and just barely) legal in terms of honouring the GPL. But legality has no correlation with ethics or morality. I simply encourage your readers to do their own investigation, do a small bit of their own thinking, and make their own determination.
The H: What are some of the more recent developments within the FlightGear project that stand out to you?
CO: Over the past year we have made significant strides in the area of graphical effects and creating more accurate and realistic renderings of the world.
- We now have very realistic ocean/water effects that include things like sun glint, foam (that occurs due to breaking waves when the wind speed is in excess of 12-15 knots), varying sea colour, wave intensity, and wave direction that tie directly into the weather modelling system. For my day job I have used this accurate ocean modelling as a tool to assist in developing and testing a computer vision software package that will ultimately run on a real UAV and scan for ocean debris. People can call this "eye candy", but I call it an indispensable tool for use in my day job!
- Last fall, one of our core developers launched "Project Rembrandt". This is a set of rendering techniques and tricks within FlightGear that will accurately model universal shadows and illumination. It is still being developed and refined and integrated with our other graphics effects, but it shows tremendous progress. It allows us to accurately model a large number of directional lights in the scene: things like the rotating beacon on a ground vehicle, landing lights, cockpit illumination – all accurately illuminating the aircraft and its surrounding environment. It enables support for 100s of spotlights in an airport environment (that can be made brighter or dimmer by the user). It will allow terrain to cast shadows on itself, buildings to cast shadows, dynamic models and AI traffic to cast shadows – essentially everything casts a shadow on everything for the ultimate in shadow realism.
- Another core developer has been doing incredible work modelling very subtle (but important) details to achieve correct sky illumination and colours, correct cloud illumination and colours, correct fog and haze. He has been modelling different amounts of haze, pollution, humidity, factoring in the time of day (sunset, sunrise, day, night, etc.), and factoring in the altitude of the viewer. This is a huge matrix of variables that are incredibly difficult to get exactly right under all conditions. But the results are visually stunning and ultra realistic. Call this "eye candy"? Call this accurately modelling the physics of light and illumination in our sky, clouds, and haze? I think again that this serves as an example of how the FlightGear project often goes the extra mile to model the underlying physics and science correctly, rather than using quick graphics tricks and illusions to achieve something similar (but with less variety).
Ultimately, any simulation is the combination of art, science, and engineering. The best simulations will find the best balance between all of these. FlightGear doesn't claim to have found the perfect balance yet, but this is the direction we are intentionally working towards.