Engines and Thrust

[robotarozum]

Engines are confusing. In game, the only figures given are on the start screen, any upgrade is mysterious. On the wiki, thrust is listed for the upgrades but appears to be listed as thrust/mass for the ships. I believe I have calculated the thrust values for each ship correctly given their starting loadouts:

Wolfen
2.0 + 1.0 + 14 * .05 + 1.5 + 4 * 2.8 + 14 * 0.1 = 17.8
13.1 * 17.8 = 233.18
thrust satisfying rounding = 233 or 234

Sapphire
2.5 + 1.0 + 4 * 3.0 + 14 * 0.1 = 16.9
6.6 * 16.9 = 111.54
thrust = 111 or 112

EI500
1.0 + 1.0 + 4 * 2.5 + 21 * 0.1 + 7 * 3 + 4 * 1 + 0.001 = 39.101
1.5 * 39.101 = 58.6515
thrust = 57 through 60

...but the thrust for the NPC EI500 is listed as 200. Not sure if that has anything to do with anything. If the math is at all accurate, it suggests that the useful drive upgrades are:

Wolfen - titan for thrust only, pterac
Sapphire - titan and pterac
EI500 - all

It's possible the stock reactors and drives also count for weight, which would always mean the thrust values listed above are understated, but I can't think of any way to test that without a speedometer or something. It also seems like the tritium upgrade is barely useful as is, if the EI500's base thrust was too terribly much higher it would be a trap item.

I also have no idea how or if maneuverability is impacted by drive upgrades, but (because?) maneuverability is a little iffy as far as physics is concerned already. To be clear, I wholeheartedly support not having to use the main drive for all turns from a playability perspective, it just makes things weird trying to figure out whether upgrading my rear-facing main drive has anything to do with my invisible turning drive.

[george moromisato]

Code: Select all

thrust-ratio = (2 * thrust) / mass

mass in metrics tons

A few other points:
1. Mass includes all installed items + cargo + hull mass.
2. Drive upgrades always ADD to thrust (they don't replace the original drive). So an upgrade always helps thrust-ratio.
3. Maneuverability is not improved by drive upgrades.

Unfortunately, some of those values are difficult to reverse engineer. For example, I don't think TransData outputs total mass of a ship class, so you would have to compute that the hard way (add up all the items). Worse, I don't think the game tells you the new thrust-to-weight ratio after you've installed a drive upgrade. Both of those sound like new features for the future.

Hope that helps!

[robotarozum]

Ohh. Yes, that helps a lot, thanks Mr. Moromisato!

[sun1404]

Drive upgrades add to thrust? I was sure it just replaces the stat. Was it like that all along or changed recently?

Also, if there is a way to change the maneuverability of a ship, an upgrade for that stat would be very useful.

[pixelfck]

Drive upgrades add to thrust? I was sure it just replaces the stat. Was it like that all along or changed recently?

Same here.

The rotation is a bit tricky at the moment. a maneuver value of 2 for 20 faces ships results in twice the rotation speed of the same maneuver value for a 40 faces ship. Having said that, I agree that it would be great if a) we could build devices that affect manoeuvrability and b) the rotation speed would allow for finer settings.

~Pixelfck

[george moromisato]

Drive upgrades add to thrust? I was sure it just replaces the stat. Was it like that all along or changed recently?

Same here.

The rotation is a bit tricky at the moment. a maneuver value of 2 for 20 faces ships results in twice the rotation speed of the same maneuver value for a 40 faces ship. Having said that, I agree that it would be great if a) we could build devices that affect manoeuvrability and b) the rotation speed would allow for finer settings.

~Pixelfck

I believe it's been that way from the beginning. Here is the relevant line of code:

https://github.com/kronosaur/Transcende ... .cpp#L5973

I think the game UI needs to expose this to the player; there is no way one would know about this otherwise.

As for maneuverability, I have this near the top of my list. I would like to fix the following:

1. Support maneuverability in degrees per tick (or, alternately, ticks per full rotation).
2. Fix the problem with ship with > 40 facings (which have a problem with maneuverability because each facing is a non-integral number of degrees).
3. Add some way to enhance maneuverability.

[robotarozum]

Fine rotation for maneuverability seems easy to me: if the brake is held, the ship only rotates one facing per touch. Or add a rotation brake, perhaps mapped to comma.

.

Another thing I saw on the wiki was the question of the effect "enhanced" had on engines. Thrust is very difficult to measure empirically, but top speed is pretty easy, so I did...

Sapphire base engine (.2c) went 12 squares in 2:19
Sapphire with enhanced Titan went 12 squares in 1:40
Both cases I gave myself a full square to get up to top speed, which was way more than enough. I also disregarded relativistic effects.

Thus, each square is...
12 squares * x ls / square = 139 seconds * .2 ls / second
x = 2.136 ls
...which is sort of a weird number, but if we say I was 1 second off and make it 140 seconds, that gives us 2.3, which makes more sense. Or 138 seconds and 2.3 flat.

The base Titan is listed at .25c, and empirically we find...
12 * 2.3 = 100 * x
x = .28
...so I would guess 10% (102 seconds) or 15% boost (97 seconds), plus it might round to the nearest hundredth. If we use 2.3 flat, we get x = .276, which is very close to .25 * 1.1 = .275. The simplest explanation seems to be box = 2.3 ls, thrust enhancement = 10%.

If I come across a pteracnium megadrive I can test again, which would also help demonstrate whether the effect is % or +.

[PM]

Enhanced engines are 10% more powerful. Enhanced megadrive has top speed of .33c.

[robotarozum]

I got my hands on a pteracnium megadrive. In the system I was in, I found...

18 squares = 2:30 sapphire base = 1:30 enhanced pterac

First, this shows that the enhanced pterac is about 150/90 * .2 c = .333 c, so empirically it is probably as PM says and enhanced engines give 110% max speed.

Second, 18 squares at .2 c in 2:30 shows 18 squares = 30 light seconds, 1 square = 1.66 light seconds. My guess is that the boxes are drawn particular to each system in units of x/3 of a light second, where x could be determined any number of ways (star type? # of orbits? random?). As shown above this doesn't really matter, the easiest way to see relative speed is to use a fixed number of boxes, then neither the number nor the size of box matters. I just thought it was interesting.