You can do preliminary comparisons between ships by comparing turbo thrust to weight but I wonder what role initial cruise thrust plays in a ships turbo.

So what is the formula for calculating the rate of acceleration of ships? Does it include initial cruise thrust over weight plus turbo thrust over weight or is it just turbo thrust (maybe multiplied by a fixed multiplier) over weight?

Also, what happens when you hit that last 10% or so near the max, is there any variability there or is it merely a fixed percentage slowdown?

Googled the forums for the answer but nothing popped up so figured i'd ask.

Normal engine thrust and turbo thrust are independent of each other. If your turbo is active, the normal engine thrust is not.

The engines generate a force that is then applied to your ship with the standard a = F/m formula.

There is a drag effect against your velocity direction as you reach the maximum speed of the engine/turbo, something like this:
drag = speed * (((speed-maxspeed+thrust const) / thrust const) * (thrust const / max speed))

The force is calculated something like this:
F = thrust const - velocity*drag

This isn't exactly what goes on, there are some other calculations to deal with things like flight-assist and the drag magnitude is actually related to the cross product of the thrust direction (aka ship direction since thrust is always opposite of your ship's direction) and the velocity.

i smell a hack in the works

You are a strange man greenwall.

Thanks for the explanation ray, that's more or less what I suspected to be true but I wanted to be sure.

The only other question I have leading on from that is about F/A mode vs Physics mode and applying the brakes.

It feels like the following occurs:

Braking in physics mode applies equal force in all directions eventually leading to a full stop, whereas F/A mode applies brake force is every direction except the one you strafe in (and forward motion if you increase the throttle).

This seems to lead to it being much faster to change directional strafe in F/A mode rather than physics mode even if you apply perfect counter keystrokes. Is that accurate or am I missing something about the mechanics?

Brakes are applied the exact same way in both flight models. It applies a force in the opposite direction of your velocity.
Flight assist is a layer on top of physics mode, so whatever F/A can do, the physics mode can do, too. (except for the one max-speed damper that prevents you from going over your max speed in physics mode).

This is one of the things I love about VO.

F = thrust const - velocity*drag
I assume you mean "F = thrust const - drag"? lol, otherwise it gets kinda weird

Anyways...

drag = speed * (((speed-maxspeed+thrust const) / thrust const) * (thrust const / max speed))
F = thrust const - drag

This is interesting. Plotted against velocity [in the direction of motion] for Vulturius stats, that thrust looks like this. I always thought it would look more like this or this. Does that mean you actually get an acceleration bonus beyond your base thrust for accelerating against your direction of motion?

No, drag is a scalar, so you can't subtract a scalar from a vector. I guess i could have made all vectors bold or something to help understand what's going on.

But those formulas aren't exactly what's going on.

drag = ship_forward_vector DOT unit_velocity_direction
drag *= (((speed-maxspeed+thrust const) / thrust const) * (thrust const / max speed))

There's a force damper that is applied if your ship is moving faster than the max speed (or max turbo speed if turbo is engaged)

damper = -unit_velocity_direction * thrust const * 2

so
Force = damper + (ship_forward_vector * thrust const * control) - (velocity*drag*control)

where control is a number from 0 to 1 that is your joystick axis or button (which would make it either 0 or 1).

No, drag is a scalar, so you can't subtract a scalar from a vector. I guess i could have made all vectors bold or something to help understand what's going on.

Nah, I gathered as much. I was just taking the case in which the ship can only move forwards/backwards just to make it simpler. I think in your last post you just multiplied drag by speed one more time than was necessary, is all (but you fixed it in the followup).

One assumption that I did make, though, was that "speed" as it appeared in the drag formula wasn't abs(velocity) but more like "velocity dot ship_direction". E.g. positive if the player's thrusting in their direction of motion and negative if they are thrusting against their direction of motion. That's how I got the graph that I got, where the player gets slightly over 230 N of force in a CorVult if they are thrusting against their direction of motion. Is that the case or do you just make drag 0 if (unit_velocity dot ship_direction) < 0?

Also if I plot the same case (forward thrust only, x-axis being vel dot ship_dir, and y-axis being output forward thrust) for the system in your above post (assuming the "proper physics" definition of speed as it suggests), I get this. Is that more accurate?

Thanks for taking the time to math with us, btw. I really respect the VO flight model; I'm just interested because it gave me some of my all-time favorite gaming experiences.

drag is not clamped, it is allowed to go negative if you are facing the opposite direction of your velocity.

I've never graphed the engine forces, the formulas were based on 'feel'.

Thanks for enjoying VO!

drag?..in space?--the vacuum of space???
I THINK NOT!!
inertia (resistance of a body to a change in motion) yes.
talk amongst yourselves...
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yes, its a video game. just wanted to throw a melted marshmellow in in the path of ur new jordans.

Little known fact: VO is actually fluidic space.

Space is not a vacuum

all the spacedust generated by mining drags ships down, also why they can't go faster than 225m/s.

You can't explain that!

The amount of fluids in wormhole systems is ridiculous. That's how

spidey spent too much time reading his Playboy magazines in the wormhole sector.

ITS LIKE A SNOWGLOBE!