Besiege essentials: Downwash air physics

This is by far one of the most essential physics propeties required in Besiege in the next major update.
Also I'd like to note that the developers don't pay much attention to the community's suggestions. They just add things to the game without opinion of the people who play it. I just want to ask that the game devs should be more open to our ideas.

Now, back on topic. The community is daily building bigger and more advanced in Besiege, with all its current capabilities and features. But then sometimes ideas come to a stop when there's limitations in the game's physics, and I have a small idea that could keep Ideas rolling further.
It's simple. You all know that helicopter rotors make that big wind downwash under them, due to the huge air displacement caused by the blades. that's exactly what besiege needs. The ability to create wind from propellers. This would add new major things into the game, like the ability to create hovercrafts and powerful fans.

It would also be relatively easy to program into the game. The downwash could be an invisible ray produced by a moving or rotating propeller, that increases in power as the amount of life the propeller produces, and the ray decreases in power hrough distance, simulating real life physics. the collision of the ray with the ground produces additional lift, but at a certain stable height of the ground (which depends on the power of the "ray") and creates hovering.

This would be a great addition to Besiege, and would definitely make the workshop more interesting.
I would also love to see this with steam, because i tried making a hovercraft but failed. The steam lifts you or don't, there's no sweet spot where you are able to hover like TekmastR said.


Staff member
Hmm, there are some problems with what you wrote, I think:
1. "Surrounding the base of the ACV is a flexible skirt, also called the curtain, which traps the air currents, keeping them underneath the hovercraft. These trapped air currents can create an air cushion on any smooth surface, land or water!". Hovercrafts would require gas-physics, which is in the same league as liquid-physics
2. Why would a helicopter get more upforce if the air from the propeller hits the ground? There's no magic link between the displaced air and the cause of the displacement. Hovering helicopters hover because they either calculate the exact force needed to counteract gravity, or by doing adjustments to make sure they stay in about the same place
3. For a more realistic wind experience, several raycasts would be required for each block, to make sure all parts of the block create lift. This can cause a lot of lag (Refer to mod in attachment for how it is without lots of raycasts)

Attached Files


Staff member
Hmm, didn't know about that, though it seems like this affects the wings or the body of the vehicle (not sure I understood the wiki page correctly), which again would require gas-mechanics or multiple raycasts
The physics would be able to allow hovering because it is creating a stable flow of air that creates a cushion between the craft and the ground. same as ACV's, it creates a cushion. No gas physics are needed.
Also, I really want this hovering thing off the ground and implemented in besiege, because i have plans for a hovercraft racing league :)


Staff member
''flow'', ''cushion'' and ''craft'' is only possible with gas physics, unless you can suggest a different way that doesn't involve tons of raycasts
The developers pay copious amounts of attention to what the community asks for, but the community doesn't necessarily speak with one voice, rather people see the game individually and have their own thought and preferences. Thus the devs try to accommodate for what is needed to reach internal and external wishes. So get over yourself.

Making simulated air is like finding surrounding objects and applying forces to them, which not only would be laggy, but would be quite likely to not work at all like you would want it to. All in all it seems like an obscure feature, that while it sounds cool would just be way too messy.
"It would also be relatively easy to program into the game."

Says the guy who joined the modders slack to... Well, mod, but keeps procrastinating and still hasn't modded anything.
And you probably have no clue how programming works anyway Tek ;)
you can generate a kind of zero gravity. almost works same way.this way it act like a hovercraft..
and with steam try adding a few steam cannons pointing up so u find the sweet spot and you dont take off..

atm. im working in scrap mechanic on VTOL and 2 legged movement.. thats why u dont see me that often atm.
thrusters there works like steam cannons here..

got a propelled example here.
my other stuff is gone cause i had to reinstall game and forgot to save creations folder :(