I haven’t played today so it’s 9231. I’ll update and see if I can replicate the problem.
The stats don’t continue to decrease now like they did previously but I still get reduced stats that take about half an hour of resting to get back after just smashing one zombie when I’m on two bars of stamina when I start. Feels kinda off even with an arm splint.
1 Like
Water and air are fluids, and drag in fluids is determined by the fluid drag equation:
Force of drag = 1/2 * density of fluid * area * velocity^2
Density of air is roughly 1 kg / m^3
Density of water is roughly 1000 kg / m^3
So the water drag of 3.43 seems pretty likely to be correct.
I’ve got a PR to reduce manual engine power in the works; let me poke at this some more.
Quick tests show that running a bicycle on pavement at safe speeds (~14 mpg) is draining about 1/2 bar of stamina per second, which is way too fast. Muscle powered vehicles should drain stamina at safe speeds, but just barely. I’ll work with mr_sep on it.
1 Like
I was talking about buoyancy I guess, water will actively try and push you up (and out) if you are floating while with air you “sink” (unless you have a lighter then air vehicle), so with air drag it’s something you are experiencing across the entire face of the vehicle were as a water based vehicle you only experience water drag across the portion of the vehicle that has displaced the water. With the boat being shaped right, the upward force of buoyancy and forward motion should reduce drag even more as the front end of the boat is pushed upward in the water reducing your surface area.
(None of this is me claiming you are wrong, just explaining what I ment when I was taking about air and water drag being different)
Not an expert though and I’m not going to pretend to be.
Does the game currently take vehicle shape into account when it comes to water vehicles? If not, does it just assume the front of the vehicle is just flat/square or how aerodynamic (hydrodynamic maybe??) does the game assume the boat is?
That aside, looking forward to any changes you decide to bring in.
If I can travel for a reasonable distance at 4mph I’ll be happy with that, stopping constantly to catch my breath was driving me up the wall and was really killing my enthusiasm for hand paddled boats as a transport method.
1 Like
If that’s too much after your change to muscle powered engines feel free to lower either the base stamina burn rate for vehicles or divide load by a greater number in the calculation. If my intuition is right if you lower muscle power engine efficiency, load will rise faster towards upper speeds, thus resulting in rapid raise of stamina consumption. This means that after the change the stamina drain calculation has to be adjusted accordingly to the desired values.
I haven’t found any good equations for determining hydrodynamic lift, but most CDDA watercraft are amphibious vehicles and low speed (often muscle powered) boats that almost entirely support themselves through buoyancy and water displacement. As far as I can tell, water planing hulls have to be going fairly fast to get significant lift (and therefore depth reduction to reduce wetted surface area and water drag) and CDDA water vehicles don’t go much faster than 30 mph.
If you have any references for when and how much hydrodynamic lift occurs on crappy, non-planing hullforms like canoes, dories, and amphibious cars, I’ll see what I can do.
CDDA assumes your boat has better hydrodynamic lines as you increase the percentage of the boat’s frames that are covered in boat hulls. It calculates hull width, hull length, and assumes a kind of “boat-ish” hull form(1) to calculate the vehicle’s volume, and then calculates displaced water mass and depth from that. The boat’s surface area in the fluid drag equation is width * depth, but the “fineness” of the hull influences the boat’s coefficient of drag for water.
(1) it’s a approximate as a rectangular prism for the back half of the vehicle’s length, and a pyramidal prism with a base width of the boat’s width, an x-y height of half the boat’s length, and and an x-z height of the boat’s depth. Obviously, a real boat would have curved hull form, but that form is easier and quicker to calculate.
Anyway, I finally got around to reducing the stamina cost of muscle powered vehicles last week. Soon I’ll reduce the power of muscle powered engines to match.
1 Like
Like I said, I’m no expert. I’m just a guy that’s read about a lot of different things over the years and some of it has stuck with me. I’m glad you had a look at stamina costs for boats and after the changes for muscle powered engines come in I’ll probably revist them at some point.
Good to hear that boats are going to be useful again!