Prancer
Junior Member
Jousting in space. We're all Knights of the Stars.
Posts: 57
|
Post by Prancer on Mar 21, 2017 1:40:04 GMT
plus.google.com/+IanMallett/posts/PrJsph3RLxSIn this page somebody writes some thoughts on space warfare that he garnered from his experience with Children of a Dead Earth. There are a couple of points he raises that I dislike, namely that lasers are useless weapons and that the missile makes it so that warships would not be built. While I have my own thoughts and refutations, I was wondering if you could provide some of your own responses to this?
|
|
|
Post by deltav on Mar 21, 2017 1:55:20 GMT
plus.google.com/+IanMallett/posts/PrJsph3RLxSIn this page somebody writes some thoughts on space warfare that he garnered from his experience with Children of a Dead Earth. There are a couple of points he raises that I dislike, namely that lasers are useless weapons and that the missile makes it so that warships would not be built. While I have my own thoughts and refutations, I was wondering if you could provide some of your own responses to this? I think his response is based on just playing around with COADE without finishing the missions or getting into design. For instance he talks about the bloated laser station as an example of what lasers can do. I admit I too was led astray by the Laser Station when I first started playing COADE, and it made me a lot of frenemies that I refused to see the light for so long. I think everything written here is from that perspective of someone who never saw what is really possible with design. I think most COADE players give up too early, module and ship design is where COADE really shines. Also this was written before 1.10, the update that really changed almost everything in COADE from Railguns, to Coilguns to Lasers. In short, the guy is a decent writer, but didn't spend much time with COADE, and it shows. Plus his review is outdated. My two cents.
|
|
|
Post by samchiu2000 on Mar 21, 2017 8:17:56 GMT
I do agree with his point that missile is the king of COADE~
|
|
|
Post by mrsandman on Mar 21, 2017 16:51:09 GMT
plus.google.com/+IanMallett/posts/PrJsph3RLxSIn this page somebody writes some thoughts on space warfare that he garnered from his experience with Children of a Dead Earth. There are a couple of points he raises that I dislike, namely that lasers are useless weapons and that the missile makes it so that warships would not be built. While I have my own thoughts and refutations, I was wondering if you could provide some of your own responses to this? The problem with him saying that k-slugs are king is that everything but old needleguns lacked the velocity of lasers. Now, I don't know if we'll ever see railguns with such velocities. While they can do more damage, since the meta is 1000km laserstars, it could have taken even a good needlegun 5 seconds to reach the target. Lasers are instant. I doubt he did much research in either the games module designer or even the forums, cause he'd see how bloated and inefficient the stock ships/modules truly are. Like how the Laser Station is one of the most bloated designs, beaten only by the stock Shooting Star IMO.
|
|
|
Post by AdmiralObvious on Mar 21, 2017 20:42:26 GMT
The document was written in September, and if I remember right, Magnetic Metal Coils were still defying the laws of physics at the time. So, partially, if he messed about with those, I can easily see where his conclusion of "kinetics beat everything" idea came from, if he bothered to tamper with the designers.
I also think that, while the stock designs may be "bloated" one thing that makes them sensible to draw real world conclusions from is the fact that every component isn't min-maxed down to the last single Kelvin of total meltdown, contrary to what I assume most of us on this forum typically do.
His comments on maneuverability isn't totally wrong, but that can easily be resolved by tweaking the gumballs on the rockets, or adding radial thrusters, which a select few of the stock ships have, but in most cases, they're fairly low thrust Resistojets.
I didn't really read through the whole article, but I skimmed through it, and can see why the guy made his "first impressions" as they are.
|
|
elukka
Junior Member
Posts: 73
|
Post by elukka on Mar 27, 2017 16:13:41 GMT
The lasers in his mind have the same issue the default lasers in the game have: Comically small apertures. He's talking about a 2 mm (!) aperture in his example. That's not an anti-ship weapon, that's a laser pointer you bug your cat with. A real life design for an orbital anti-missile laser, Zenith Star, featured a four meter mirror: i.imgur.com/T7Yi0Kq.pngThe first thing I did with module design was take the default violet laser and replace the 80 cm mirror with a nice 10 meter mirror. Now it was melting missiles at hundreds of kilometers. Those 3 mm railguns would certainly be stripped right off a ship long before they get in range.
|
|
|
Post by The Astronomer on Mar 27, 2017 16:31:13 GMT
The lasers in his mind have the same issue the default lasers in the game have: Comically small apertures. He's talking about a 2 mm (!) aperture in his example. That's not an anti-ship weapon, that's a laser pointer you bug your cat with. A real life design for an orbital anti-missile laser, Zenith Star, featured a four meter mirror: i.imgur.com/T7Yi0Kq.pngThe first thing I did with module design was take the default violet laser and replace the 80 cm mirror with a nice 10 meter mirror. Now it was melting missiles at hundreds of kilometers. Those 3 mm railguns would certainly be stripped right off a ship long before they get in range. That's way too large for me. My lasers use just 1.5 m, but higher power. Anyways, I guess that person won't even care to touch this game anymore, right? *sigh* Anyways, who is Tmp Adr?
|
|
|
Post by deltav on Mar 27, 2017 22:06:36 GMT
The lasers in his mind have the same issue the default lasers in the game have: Comically small apertures. He's talking about a 2 mm (!) aperture in his example. That's not an anti-ship weapon, that's a laser pointer you bug your cat with. A real life design for an orbital anti-missile laser, Zenith Star, featured a four meter mirror: i.imgur.com/T7Yi0Kq.pngThe first thing I did with module design was take the default violet laser and replace the 80 cm mirror with a nice 10 meter mirror. Now it was melting missiles at hundreds of kilometers. Those 3 mm railguns would certainly be stripped right off a ship long before they get in range. That's way too large for me. My lasers use just 1.5 m, but higher power. Anyways, I guess that person won't even care to touch this game anymore, right? *sigh* Anyways, who is Tmp Adr? The writer in question seems to be a sort of Project Rockets type guy who is mainly focused on Hard Sci Fi, not necessarily on gaming. His blog sounds pretty interesting, would be good for Scifi Writers to get ideas. plus.google.com/collection/AA3jkB
|
|
|
Post by imallett on Mar 28, 2017 18:28:09 GMT
Hi all, I'm the OP of the original post linked. Just a few random clarifications/notes: - I played through the whole campaign shortly after the game was released, and I believe before I wrote the article. I did it using a combination of stock ships and custom ships, with custom ships mainly being railgun spam. This was indeed before some patches made railguns less effective (I didn't follow it closely, but some of my hypergun designs might have played a role in motivating these patches). In my view, guns still beat lasers, though:
"The stock lasers are pretty anemic; it seems that titanium-sapphire + xenon, plus carefully tuning the frequency doubler and nonlinear optics is the optimal choice for efficiency (means smaller radiators), and they're almost competitive with railguns for range, although the diffraction story still plays out for irradiance."
This is more-or-less still true. Also, the laser stations mentioned were custom-designed and used these lasers.
- Most of the analysis is indeed not game-based. As in, missiles and railguns should be more effective than they are, but the game has limitations (bad targeting, tracking AI, performance limits on number of K-slugs in flight). As deltav guessed, I'm affiliated with projectrho, which does hard-sci-fi analysis, not so much gaming. So, I try to combine real Physics and the odd simulation when CoaDE doesn't get it just right.
In particular, total internal reflection, Fresnel and secant losses, and slanted armor make a huge difference for lasers, but AFAICT CoaDE doesn't simulate them at all--and its simulation of divergence appears to be an attenuation instead of an actual spreading.
- The 2mm laser aperture example was deliberately to show that small apertures are bad. Read the paragraphs following.
- There has been some additional discussion and analysis of CoaDE's limitations in the comments of the original post, which might be worth reading.
|
|
|
Post by darkwarriorj on Mar 29, 2017 0:23:10 GMT
- In my view, guns still beat lasers, though:
"The stock lasers are pretty anemic; it seems that titanium-sapphire + xenon, plus carefully tuning the frequency doubler and nonlinear optics is the optimal choice for efficiency (means smaller radiators), and they're almost competitive with railguns for range, although the diffraction story still plays out for irradiance."
This is more-or-less still true. Also, the laser stations mentioned were custom-designed and used these lasers.
- In particular, total internal reflection, Fresnel and secant losses, and slanted armor make a huge difference for lasers, but AFAICT CoaDE doesn't simulate them at all--and its simulation of divergence appears to be an attenuation instead of an actual spreading.
Hey Ian, the article you wrote was pretty cool. In regards to your points though, I have two major questions here: 1. Currently I'm finding that I can build lasers which can effective lase enemy armor to pieces out to 1000km, the game's hard cap, with ease, and can build lasers which can reasonably mounted on ships which have far greater ranges - tens of thousands or even a hundred thousand km effective range, if the game would let me actually use them with that range. With railguns and the revamped actually correct model, I cannot do such a thing. Even theoretically, it seems to me that railgun's effective ranges fall off dramatically fast compared with lasers. What factors am I missing when it comes to railgun ranges being superior to lasers? Is it perhaps that area saturation could increase the effective railgun range but is not modelled in game, for example? Even that seems to be of limited utility given the sheer range lasers could have, some dodging thrusters and the incredible amount of time a railgun bullet would need to travel across 10 000km, for example, so is there anything we're missing here? 2. Can you explain more on the effects of total internal reflection and other such effects for lasers? I mean, I know what the first thing is (not the second or third though), but what effects do they have on laser damage, and under what circumstances do they apply? Also, my impression is that CoaDE's laser damage model is a work in progress. Some other things which currently work against lasers to my knowledge is the lack of impulse shock type damage for lasers (see: Player tests involving close range stupidly high intensity lasers just cheerfully melting away a very small amount of armor without just shredding the region), as well as a hard damage per second cap which forces lasers to deal considerably less damage than they could, and also makes aerogel and ablative type armors far more effective than they should be, as well as making multiple simultaneous nuclear detonations more damaging than a single nuclear detonation when it shouldn't. Also, sloped armor effects I believe are accounted for in the simulation - or at the very least, sloped armor is in fact very useful against lasers, as it certainly improved my missile's suitability against lasers.
|
|
|
Post by Enderminion on Mar 29, 2017 3:03:29 GMT
|
|
|
Post by deltav on Mar 29, 2017 4:35:22 GMT
Hi all, I'm the OP of the original post linked. Just a few random clarifications/notes: - I played through the whole campaign shortly after the game was released, and I believe before I wrote the article. I did it using a combination of stock ships and custom ships, with custom ships mainly being railgun spam. This was indeed before some patches made railguns less effective (I didn't follow it closely, but some of my hypergun designs might have played a role in motivating these patches). In my view, guns still beat lasers, though:
"The stock lasers are pretty anemic; it seems that titanium-sapphire + xenon, plus carefully tuning the frequency doubler and nonlinear optics is the optimal choice for efficiency (means smaller radiators), and they're almost competitive with railguns for range, although the diffraction story still plays out for irradiance." This is more-or-less still true. Also, the laser stations mentioned were custom-designed and used these lasers.
- Most of the analysis is indeed not game-based. As in, missiles and railguns should be more effective than they are, but the game has limitations (bad targeting, tracking AI, performance limits on number of K-slugs in flight). As deltav guessed, I'm affiliated with projectrho, which does hard-sci-fi analysis, not so much gaming. So, I try to combine real Physics and the odd simulation when CoaDE doesn't get it just right.
In particular, total internal reflection, Fresnel and secant losses, and slanted armor make a huge difference for lasers, but AFAICT CoaDE doesn't simulate them at all--and its simulation of divergence appears to be an attenuation instead of an actual spreading.
- The 2mm laser aperture example was deliberately to show that small apertures are bad. Read the paragraphs following.
- There has been some additional discussion and analysis of CoaDE's limitations in the comments of the original post, which might be worth reading.
Thanks for taking the time to respond personally. We all appreciate you taking the time to comment on COADE and to give the game more exposure. We all have very strong opinions here, and I think if you do a search and see some of the designs you will see why we feel the way we do based on proof ingame. Nevertheless your comments are noted and appreciated.
|
|
|
Post by imallett on May 27, 2017 5:15:53 GMT
1. Currently I'm finding that I can build lasers which can effective lase enemy armor to pieces out to 1000km, the game's hard cap, with ease, and can build lasers which can reasonably mounted on ships which have far greater ranges - tens of thousands or even a hundred thousand km effective range, if the game would let me actually use them with that range. With railguns and the revamped actually correct model, I cannot do such a thing. Even theoretically, it seems to me that railgun's effective ranges fall off dramatically fast compared with lasers. What factors am I missing when it comes to railgun ranges being superior to lasers? Is it perhaps that area saturation could increase the effective railgun range but is not modelled in game, for example? Even that seems to be of limited utility given the sheer range lasers could have, some dodging thrusters and the incredible amount of time a railgun bullet would need to travel across 10 000km, for example, so is there anything we're missing here? It might not play out particularly well in-game, but the main intuition here is that both lasers and k-slug weaponry suffer an inverse square falloff—but for lasers, it's effectiveness whereas for rail-/coilguns it's accuracy. I've been playing around more with the lasers in-game. The biggest laser module I've ever designed has an output power of 978 MW, and an intensity of 8.5 TW/m^2 at 1000 km. Naturally, it has a 100m aperture and takes 10 GW to run. The ship it takes to run this thing is 1.72 km long, has 0.4 sq. km of radiators, and masses 4.75 Mt. Now yes, this monstrosity could, if the game supported it, reasonably attack things a few light seconds away. I found that reducing the aperture a bit helped with destruction (so it seems COaDE does model laser area, contrary to my prior statement) and also allows for turreting (since slewing the whole ship is impossibly slow), but either way, it punches right through just about anything at the maximum in-game limit, and it can fry entire swarms of missiles. But, this thing has a cross-sectional area about 10x that of what astrogators regularly hit with ballistic interplanetary ship trajectories, even with today's technology, in real life. So, all I need to do is just pelt the general vicinity with k-slugs from light minutes away. I hit a radiator, and your laser drops efficiency. I hit enough of them, and it's dead. I hit that huge focusing mirror, and it's dead. I hit the reactor, and it's dead along with you. Even if you could see the k-slugs on radar far in-advance (which you probably can't, because radar scales as inverse fourth power of distance), and maneuver out of the way somehow, you can't do that forever. It could take literally months of high-impulse dodging for your laser battleship to get close enough to fight back. The only realistic defense is to hope the laser can ablate-thrust the projectiles out of the way, which it essentially can't—you can make projectiles big, narrow, and fast, and with slanted armor you can leverage secant and Fresnel /TIR losses (discussed next). Essentially, lasers lose their effectiveness at distance in a way that railguns just don't. And if you try to scale the laser to compensate, the larger target just makes railguns effective even farther. I will grant that this is not always the case in-game, since the engagement limit is tiny. 2. Can you explain more on the effects of total internal reflection and other such effects for lasers? I mean, I know what the first thing is (not the second or third though), but what effects do they have on laser damage, and under what circumstances do they apply? ... Also, sloped armor effects I believe are accounted for in the simulation - or at the very least, sloped armor is in fact very useful against lasers, as it certainly improved my missile's suitability against lasers. When light hits a surface—any surface—the Fresnel equations apply. These determine what fraction of the light reflects away from the surface and what portion refracts into the surface. The refracted light is then absorbed by the material via the Beer–Lambert Law (for "opaque" surfaces this happens very rapidly). "Fresnel loss" refers to the fact that the reflected light does not damage the surface. Only the refracted light can be absorbed and cause damage. Usually taken to refer to the tendency of materials to reflect more at steeper angles. Practically every surface does this, but it's easiest to see on glossy surfaces—try it! Look at an angle and see the stronger reflection! "Total internal reflection" is a related phenomenon where, for some refractive index pairs and incident angles, 100% of the light is reflected. The extreme version of a Fresnel loss. Not "nearly" 100%; exactly 100%. If you want to try this, the easiest is in the pool/ocean (a " Snell window"). Relevant here, any laser attempting to damage a surface in a TIR configuration will do absolutely nothing, regardless of its intensity—such as the Aluminum armor example I gave in the link."Secant loss" is the fact that light falling at an angle on a surface is "spread out"; the irradiance reducing by a factor of 1/cos(angle), the secant. It's the main reason we have seasons on Earth. In-game, you're right about the sloped armor being taken into effect. Absolutely mandatory for k-slug defense. For lasers, I suspect secant loss is modeled, but not Fresnel or TIR. I tried a thin-Aluminum-armored missile vs. the stock Cutter (using it's 532nm green laser only), and the laser still shot the missiles down handily. In reality, the laser should TIR off the missile's hull at anything more than 64.39 degrees. As you can see, the laser (erroneously) damages even the portion of the armor nearly 90 degrees to the laser (orig):It's worth noting that this example depends on the wavelength being known. Refractive index is wavelength-dependent, especially for metals. For 532 nm, Aluminum's is 0.90175. Since it's less than vacuum (refractive index 1), TIR is possible. This is not the case for other wavelengths. [EDIT: The Fresnel equations depend on the the complex-valued refractive index. When the imaginary component is also taken into account, TIR is not possible for Aluminum. Sorry.]
|
|
|
Post by newageofpower on May 27, 2017 14:27:19 GMT
I've been playing around more with the lasers in-game. The biggest laser module I've ever designed has an output power of 978 MW, and an intensity of 8.5 TW/m^2 at 1000 km. Naturally, it has a 100m aperture and takes 10 GW to run. The ship it takes to run this thing is 1.72 km long, has 0.4 sq. km of radiators, and masses 4.75 Mt. Now yes, this monstrosity could, if the game supported it, reasonably attack things a few light seconds away. I found that reducing the aperture a bit helped with destruction (so it seems COaDE does model laser area, contrary to my prior statement) and also allows for turreting (since slewing the whole ship is impossibly slow), but either way, it punches right through just about anything at the maximum in-game limit, and it can fry entire swarms of missiles. First assumption problem: assuming you are optimized. childrenofadeadearth.boards.net/post/22998/threadUnder 60kt for a laser warship here, and Apophys is not using modded materials. Ce:LLF based lasers can pass 40% efficiency (although have a lower melt temperature) and in the future we'd be using FELs with 70% or better efficiency. childrenofadeadearth.boards.net/post/21241/threadWith modded materials, by bigbombr But, this thing has a cross-sectional area about 10x that of what astrogators regularly hit with ballistic interplanetary ship trajectories, even with today's technology, in real life. So, all I need to do is just pelt the general vicinity with k-slugs from light minutes away. I hit a radiator, and your laser drops efficiency. I hit enough of them, and it's dead. I hit that huge focusing mirror, and it's dead. I hit the reactor, and it's dead along with you. The problem is you're trying to shell a manouvering target at light minutes. With stock inefficiencies the Apophys design has 6.7 mg acceleration... You'll notice bigbombr's design has a ludicrous 100mg of acceleration... What are your rails? My 200km/s designs firing 1 gram graphene reinforced bullets mass over 800t each... Before power, radiator, fuel etc... Even if you could see the k-slugs on radar far in-advance (which you probably can't, because radar scales as inverse fourth power of distance), and maneuver out of the way somehow, you can't do that forever. It could take literally months of high-impulse dodging for your laser battleship to get close enough to fight back. The only realistic defense is to hope the laser can ablate-thrust the projectiles out of the way, which it essentially can't—you can make projectiles big, narrow, and fast, and with slanted armor you can leverage secant and Fresnel/TIR losses (discussed next). The above laserstars have burn times measured in weeks. Secondly, you'd never deploy a solo ship; send out a wing of recon drones to spot the incoming kinetic shells. Between dodging and lasing, closing the distance is not as hard as it seems. You should try out the current metagame - with distributed fire, missile swarms are far more manageable with high velocity railguns. In my experience, a swarm of gundrones backed up by lasers can kill hundreds of even 20 km/s attacking missiles, and with MPD tech my gundrones have 50km/s dV to reduce engagement velocity below that threshhold. Regarding TIR... Is there a good reason not to use UV or shorter wavelengths? Sub-20nm we'd need diffraction-based focusing, I guess. EDIT: In addition to FEL tech, we'd never use gigantic radiator panels on a warship. LDRs, my friend, are the future.
|
|
|
Post by bigbombr on May 27, 2017 14:37:18 GMT
I've been playing around more with the lasers in-game. The biggest laser module I've ever designed has an output power of 978 MW, and an intensity of 8.5 TW/m^2 at 1000 km. Naturally, it has a 100m aperture and takes 10 GW to run. The ship it takes to run this thing is 1.72 km long, has 0.4 sq. km of radiators, and masses 4.75 Mt. Now yes, this monstrosity could, if the game supported it, reasonably attack things a few light seconds away. I found that reducing the aperture a bit helped with destruction (so it seems COaDE does model laser area, contrary to my prior statement) and also allows for turreting (since slewing the whole ship is impossibly slow), but either way, it punches right through just about anything at the maximum in-game limit, and it can fry entire swarms of missiles. First assumption problem: assuming you are optimized. childrenofadeadearth.boards.net/post/22998/threadUnder 60kt for a laser warship here, and Apophys is not using modded materials. Ce:LLF based lasers can pass 40% efficiency (although have a lower melt temperature) and in the future we'd be using FELs with 70% or better efficiency. childrenofadeadearth.boards.net/post/21241/threadWith modded materials, by bigbombr But, this thing has a cross-sectional area about 10x that of what astrogators regularly hit with ballistic interplanetary ship trajectories, even with today's technology, in real life. So, all I need to do is just pelt the general vicinity with k-slugs from light minutes away. I hit a radiator, and your laser drops efficiency. I hit enough of them, and it's dead. I hit that huge focusing mirror, and it's dead. I hit the reactor, and it's dead along with you. The problem is you're trying to shell a manouvering target at light minutes. With stock inefficiencies the Apophys design has 6.7 mg acceleration... You'll notice bigbombr's design has a ludicrous 100mg of acceleration... What are your rails? My 200km/s designs firing 1 gram graphene reinforced bullets mass over 800t each... Before power, radiator, fuel etc... Even if you could see the k-slugs on radar far in-advance (which you probably can't, because radar scales as inverse fourth power of distance), and maneuver out of the way somehow, you can't do that forever. It could take literally months of high-impulse dodging for your laser battleship to get close enough to fight back. The only realistic defense is to hope the laser can ablate-thrust the projectiles out of the way, which it essentially can't—you can make projectiles big, narrow, and fast, and with slanted armor you can leverage secant and Fresnel/TIR losses (discussed next). The above laserstars have burn times measured in weeks. Secondly, you'd never deploy a solo ship; send out a wing of recon drones to spot the incoming kinetic shells. Between dodging and lasing, closing the distance is not as hard as it seems. You should try out the current metagame - with distributed fire, missile swarms are far more manageable with high velocity railguns. In my experience, a swarm of gundrones backed up by lasers can kill hundreds of even 20 km/s attacking missiles, and with MPD tech my gundrones have 50km/s dV to reduce engagement velocity below that threshhold. Regarding TIR... Is there a good reason not to use UV or shorter wavelengths? Sub-20nm we'd need diffraction-based focusing, I guess. To be honest, the recent corrections for the densities of graphene and 3D-graphene made acceleration and delta-v somewhat sane.
|
|