speed limits
Posted: Fri Mar 12, 2010 7:36 am
This is my first time starting a new topic, so let me just first say that I really like the idea of creating a generic space simulator that can accomodate a nearly infinite variety of user created universes and scenarios. The creation of an MMORPG that isn't mind bogglingly boring (EVE comes to mind) and uses real physics is very appearling to me.
In fact, I am seriously considering volunteering to join the development team part time (if they will have me). I have a good deal of non-graphics related programming and I am a physicist by trade. I would be most happy doing back end development of the physics engine to create weaponry and pilot assist commands that make newtonian physics based combat intuitive (which it isn't naturally) and entertaining (which is the common complaint of the x-wing style "space" sim advocates).
However, I wanted to make sure that the game is actually using newtonian physics. There are two aspects of the game that I have discovered so far that suggest this may not be the case.
1. flight mode top speeds for ships are different. If flight mode is supposed to be truly newtonian physics, the only limting speed should be c unless you are in a dense nebula or a planetary atmosphere where drag is not negligible. I understand that the developers might choose to avoid the complications of relativity by limiting ship speeds to perhaps c/100. It is also perfectly reasonable to place a speed cap due to radiation hazard. At speeds close to the speed of light, the ambient hydrogen in the interplanetary medium is traveling towards the ship at nearly the speed of light. While the drag created by these ions is not very large due to their low density, each individual ion has sufficient energy(relative to the spacecraft) to penetrate a large amount of hull plating a deliver a lethal radiation dose to any organic beings as well as damage internal ship systems. However, in either of the above cases for keeping the speed limit <c, every ship should still have the same artificial imposed speed cap(well, in the radiation hazard limit, heavily armored ships might be able to get higher top speeds than less heavily armored ships, but that is obviously not the way the current game does this). To do otherwise is to impose a non-physical artificial difference between ships. I am presuming that the flight mode top speed is a property of the individual space craft and not hard coded so that, if I wrote a mod using this engine, I would be able to make my ships all have the same top speed, but I want to make sure this is the case. I also wanted to convey my "feature request" that all spacecraft have the same top speed that is at least c/100. Immersion is really big for me in space sims, and games with non-physical speed limits just ruin the immersion for me.
2. The governor sets a requested velocity vector in the direction your ship is facing and a magnitude given by your "combat top speed". But why is this magnitude different for different ships and furthermore, why can you not select its value to be any thing you want (less than the absolute top speed of the ship obviously...discussed above). Sure, if you select too high a combat speed maximum, you may end up having a little trouble turning on a dime, but you also dont want to be stuck puttering along unable to catch your quarry because they went to flight mode and ran away. I know that there are challenges to making newtonian space combat work, but I feel that the underlying engine being created here should provide players and future modders with options in this regard rather than limiting the governor to only work at a set speed for each spacecraft. Maximum velocities sans drag (governed or not) should not be related to the ship's acceleration and should be, for the most part, the same(baring the armor argument above). Never-the-less, it may be a good idea to have space stations look out for themselves by warning craft that are traveling too fast and could potentially damage the station. Maybe they should even shoot the potential kamikazes down to avoid getting rammed at nearly light speed. Bottom line: I want to select the magnitude of the velocity vector my governor seeks to achieve rather than being told what my "combat speed" is. My combat speed is whatever I decide is the right speed cap for the situation at hand. When docking, I may want to set my speed cap to something very small. When fighting in an asteroid field, I may want it low so that my inertia doesn't carry me into an asteroid, but quick enough that I am not standing still. In open space, I may have long range weapons and desire that my ship have 0 velocity relative to my target.
In fact, I am seriously considering volunteering to join the development team part time (if they will have me). I have a good deal of non-graphics related programming and I am a physicist by trade. I would be most happy doing back end development of the physics engine to create weaponry and pilot assist commands that make newtonian physics based combat intuitive (which it isn't naturally) and entertaining (which is the common complaint of the x-wing style "space" sim advocates).
However, I wanted to make sure that the game is actually using newtonian physics. There are two aspects of the game that I have discovered so far that suggest this may not be the case.
1. flight mode top speeds for ships are different. If flight mode is supposed to be truly newtonian physics, the only limting speed should be c unless you are in a dense nebula or a planetary atmosphere where drag is not negligible. I understand that the developers might choose to avoid the complications of relativity by limiting ship speeds to perhaps c/100. It is also perfectly reasonable to place a speed cap due to radiation hazard. At speeds close to the speed of light, the ambient hydrogen in the interplanetary medium is traveling towards the ship at nearly the speed of light. While the drag created by these ions is not very large due to their low density, each individual ion has sufficient energy(relative to the spacecraft) to penetrate a large amount of hull plating a deliver a lethal radiation dose to any organic beings as well as damage internal ship systems. However, in either of the above cases for keeping the speed limit <c, every ship should still have the same artificial imposed speed cap(well, in the radiation hazard limit, heavily armored ships might be able to get higher top speeds than less heavily armored ships, but that is obviously not the way the current game does this). To do otherwise is to impose a non-physical artificial difference between ships. I am presuming that the flight mode top speed is a property of the individual space craft and not hard coded so that, if I wrote a mod using this engine, I would be able to make my ships all have the same top speed, but I want to make sure this is the case. I also wanted to convey my "feature request" that all spacecraft have the same top speed that is at least c/100. Immersion is really big for me in space sims, and games with non-physical speed limits just ruin the immersion for me.
2. The governor sets a requested velocity vector in the direction your ship is facing and a magnitude given by your "combat top speed". But why is this magnitude different for different ships and furthermore, why can you not select its value to be any thing you want (less than the absolute top speed of the ship obviously...discussed above). Sure, if you select too high a combat speed maximum, you may end up having a little trouble turning on a dime, but you also dont want to be stuck puttering along unable to catch your quarry because they went to flight mode and ran away. I know that there are challenges to making newtonian space combat work, but I feel that the underlying engine being created here should provide players and future modders with options in this regard rather than limiting the governor to only work at a set speed for each spacecraft. Maximum velocities sans drag (governed or not) should not be related to the ship's acceleration and should be, for the most part, the same(baring the armor argument above). Never-the-less, it may be a good idea to have space stations look out for themselves by warning craft that are traveling too fast and could potentially damage the station. Maybe they should even shoot the potential kamikazes down to avoid getting rammed at nearly light speed. Bottom line: I want to select the magnitude of the velocity vector my governor seeks to achieve rather than being told what my "combat speed" is. My combat speed is whatever I decide is the right speed cap for the situation at hand. When docking, I may want to set my speed cap to something very small. When fighting in an asteroid field, I may want it low so that my inertia doesn't carry me into an asteroid, but quick enough that I am not standing still. In open space, I may have long range weapons and desire that my ship have 0 velocity relative to my target.