Talon Game

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Version 1.2 released; new game mode, new map, misc improvements

#1 2014-09-22 02:41:12

Hypersonic
Member
Registered: 2014-02-24
Posts: 37

Acceleration

Request: could we have the option to display speed and acceleration in SI units?
http://en.wikipedia.org/wiki/Internatio … m_of_Units

G and KPH values are difficult to correlate with eachother
KPH is multiples of 1000 meters / 3600 sec
G is multiples of 9.8 meters/sec/sec

SI values are really easy to correlate with eachother:
SI speed is multiples of 1.0 meters/sec
SI acceleration is multiples of 1.0 meters/sec/sec

For example, with 80 mpsps acceleration I know it will take me 1 second to go from 0 to 80 mps.

I've been testing the Orion ship in patch 1.0.3. I noticed that acceleration in the opposite direction of travel is quite extreme (1 sec from max speed to stop) while acceleration in the direction of travel is quite tame (over 3 sec from stop to max speed.) Makes sense going through dense air. I suppose it's the same in Space simply for consistent gameplay, although not based on physics (no air in Space.)

Also it would be swell if future patches could list acceleration equations! I've been testing performance with a stopwatch, but it's a quite time consuming and inaccurate process.

BTW, Thanks for the awesome game!

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#2 2018-09-25 20:06:02

Hypersonic
Member
Registered: 2014-02-24
Posts: 37

Re: Acceleration

Looking at the Stiletto specs version 1.2

585 top speed & 497 strafe speed (km per 3600sec or meters per sec?)
Acceleration 6.3 (meters per second per second or a multiple of 9.8 mpsps?)
Rotation Acceleration 16 (radians or degrees per second per second?)

I'm guessing translational acceleration is in gs (or multiples of 9.8 mpsps.) Furthermore it's initial acceleration. As wind resistance rises due to relative wind speed, acceleration rapidly reduces, and I assume thrust force is the same, but eventually thrust force = resistance force = top speed.

Last edited by Hypersonic (2018-09-25 20:15:19)

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#3 2018-09-26 03:47:09

Scott
Refractory Studios
Registered: 2012-08-07
Posts: 461
Website

Re: Acceleration

I did read this thread a couple weeks ago and I thought it was a good idea. I have switched it to show acceleration in m/s² and speed in m/s as you suggested. Change will be included in the next release.

Acceleration was supposed to be in Gs, yes; although when I went to change it I could not figure out why I had used the numbers I did in the conversion from world-units/sec to G, so I'm not at all certain that what it showed was actually correct.

Ship dynamics:

Two factors cause acceleration to fall off as speed increases: drag, which increases as speed increases, and a falloff in the thrust as speed increases.

The reason I made the thrust fall off was so that I could cap the max speed at something more reasonable for close-quarters dogfighting while still keeping the drag fairly low at high speeds. If I had just adjusted the drag to be the top speed limiter than if you were cruising at anywhere near max speed and you let off the thrust, drag forces would decelerate you more rapidly than I wanted.

But the thrust falloff is directional. If you apply thrust in the opposite direction of travel, the falloff (would be negative but it is clamped so it) is zero and you have your full thrust force working to decelerate your ship, plus the drag.

The results is that stopping/"braking" is (much) faster than accelerating; and I think that's a good thing. The Griffin, for example, takes about 14 seconds to reach its maximum speed (although it gets maybe about 95% there in about 10 seconds), but can decelerate from max speed to full stop in only 2.5 seconds. This makes the ship much more controllable, and allow you to fly more aggressively and react more quickly to changing conditions; you're less likely to overshoot your target, less likely to slam into the base you were rushing to defend, better able to change course and chase after a new target, etc.

And yes, the flight model in space is exactly the same as it is in an atmosphere; to keep things simpler for the player, and for me. It's bloody hard to balance these ships and weapons so they feel good and handle well both indoors in tight tunnels and out in wide open space.

Last edited by Scott (2018-09-26 03:49:44)

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#4 2018-09-26 21:04:14

Hypersonic
Member
Registered: 2014-02-24
Posts: 37

Re: Acceleration

Awesome, thanks! Using multiples of 'acceleration due to gravity at the surface of the Earth' seems kind of odd, though one hears about 'G forces' all the time when it comes to jet aircraft. I suppose because noone has really coined a good term for SI acceleration, meters per second per second is quite a mouthful! Maybe just accel (SI).

Thanks for the info on drag and falloff thrust, it does seem to work well. So it's a little bit like Quake1's air physics where you could quickly decelerate (Half life 1 as well as it's based on the Quake1 engine.) However when flying in Quake1 you could accelerate to high speeds doing a spiral as it caps acceleration only in the direction of travel and there was no air friction.

Do the ships in Talon accelerate pretty much the same in the direction of travel as perpendicular to the direction of travel (strafe) ?
Is there another top speed for indoor gameplay as opposed to outdoor? Or is it that going super fast indoors is just silly as you'll just end up banging against walls!

I usually play on the one outdoor map Killing Fields as this is the only game with high speed 6DOF flight over terrain which is a blast (Descent3 was kind of slow outdoors.) Alot more fun than the scout ship in Tribes1. Even at 4K the framerate/motion is as smooth as silk.

Last edited by Hypersonic (2018-09-26 21:14:23)

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#5 2018-09-26 22:40:43

Scott
Refractory Studios
Registered: 2012-08-07
Posts: 461
Website

Re: Acceleration

Without the Afterburner, acceleration is the same in any direction from a standing start, but the thrust falloff is extended a bit in the forward direction so the thrust going forward does not fall off quite as fast and the top speed is a bit greater.

The Afterburner adds a bit more forward thrust off the line, and further extends the thrust falloff in the forward direction for somewhat better acceleration and even greater top speed.

Flight dynamics are the same indoors as out, the top theoretical speed is the same, although it's not possible to realize any of the ship's top speeds in any of the indoor maps currently in the game.

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