Update log
Full SimplePlanes 2 update
The complete published notes, normalized for clean reading and source attribution.
Extracted changes
- Gameplay
Welcome to Part 3 of our set of blogs showing off the new wings! This one goes into some more enhancements to visuals and physics, so let's get into it, starting with...
Propeller Blur
Er... propellers are technically wings, right? I know, put away your nerd emojis, I just had nowhere else to put this. So anyway...
When something like a propeller blade spins very fast, it creates a blur effect that is rather plainly called motion blur. Propellers had motion blur in SimplePlanes 1 but it was very basic, merely being a flat rotating texture. Because of that, they had various visual shortcomings, mainly that they were infinitely thin from the side and they didn’t really interact with the lighting in a convincing way.
So for SimplePlanes 2 we “borrowed” a technique Philip had previously developed for version 1.1 of Juno: New Origins for proper 3D motion blur on propellers, giving them actual depth, better lighting, and overall much better visual fidelity. Not only that, but the blur properly adapts to the current properties of your propeller like the shape, RPM, or pitch!
This effect looks much better than the old motion blur – so much better in fact that we’ve also applied it to helicopter rotors! Additionally, it holds up much better than before in slow motion or when paused, showing the blades partially blurred but not with the full intensity seen at regular speed.
Propellers and rotors now also have new XML properties that let you customize parts of the motion blur’s behaviour, letting aesthetically-minded technical players get their hands dirty to make things look how they want if the default values aren’t cutting it.
Spanwise Flow
In the Wings Part 2 dev blog, we went over some of the physics for the new wings in SP2. This section will elaborate a bit on one aspect of those: “spanwise flow”
In real life, wings produce different amounts of lift across different parts of the wingspan, with lift gradually being reduced towards the tip of the wing. This wasn’t modeled in SP1, meaning the whole wing produced the same amount of lift, which left a lot to be desired.
SP2 on the other hand has a whole spanwise flow model developed by Nicky through blood sweat and tears, simulating it and many of the resulting characteristics it gives to your wings but in a simplified enough manner that you don’t need a supercomputer to run it.
One of the biggest differences you’ll notice here is with stalling behaviour. For the uninitiated, stalling is essentially when the angle of attack of your wing (the angle of the front edge relative to the airflow) is so high that it can no longer effectively produce lift, making the aircraft drastically less controllable. In SP1 the whole wing would abruptly stall at once, but now in SP2 wings will gradually stall from the tip to the root, resulting in generally much more gentle and realistic stalls.
“Induced drag” is also modeled now, essentially being extra drag that comes as a direct result of the lift your wings are producing. More efficient wing shapes such as those with a large wingspan will have less induced drag than
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