# Calculating velocities

I'm wondering which is the better way to handle velocities...

1. Classic EV style in which standard thrusters have a maximum speed. Afterburners cause you to temporarily go over that limit, but the second you let off the afterburner your ship slowly accelerates down to it's top speed. I'm currently using this method, since it's easier to implement though less accurate.

2. Frictional environment in which the ship encounters no friction until it surpases it's maximum speed. Once the max speed has been surpased your possible acceleration tapers off as a quadratic function of how much faster you're going over the rated speed. Once you let go of the thrusters you will accelerate back down to the ships max rated speed. Afterburners provide stronger acceleration, thus faster peek speed.

I'm tempted to stick with the first style, since it remains true to the EV/EVO form, though the second method would be cool.

Thoughts?

I've also released a new version of the engine with some very significant under the hood changes, and a few noticable changes here: (url="http://"http://www.sfu.ca/~kberg")www.sfu.ca/~kberg(/url)

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The first method, though ideally you would use a proper curve. I'll post more here when I've worked it out.

--blackhole

I like the first method better, but in reallity your ship would go faster and faster until it either 1: hit something (asteroid, planet, star, etc) or 2: ran out of fuel.

but this isn't reality, so use the first method, it's more fun.

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As someone doing a lot of Physics, I would prefer the second method... far more accurate and true to life -- it would also probably be nicer to play.
However, most people are used to method #1 -- I dunno, it's your thing. Do it how you want!

C~M

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Originally posted by Mordon:
**I like the first method better, but in reallity your ship would go faster and faster until it either 1: hit something (asteroid, planet, star, etc) or 2: ran out of fuel.
**

Not necessarily, if the propulsion is non-Newtonian (which I find likely, considering how speed is measured in AUs/hour...). If the propulsion system doesn't impart any actual kinetic energy to the ship, but relies on spacetime manipulation instead, a constant energy output of the engine might be required to keep the gravitic fields up...

Then again, many ships have very conspicuous exterior rocket-type outlets. =

-- Cinga

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Originally posted by CheatMaster:
As someone doing a lot of Physics, I would prefer the second method... far more accurate and true to life -- it would also probably be nicer to play.
However, most people are used to method #1 -- I dunno, it's your thing. Do it how you want!

The second method would be nicer, but it would make the creation of balanced ships more difficult.

-- Cinga

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Just posted another build. Shows off a lot more of the newly implemented stuff. Fixed the stupid memory problem, so now SpriteWorlds blitters run again, really speeds things up.

What do you guys think about spobs having gravity? An extra field for mass in each spob would be enough. Would it throw off the gameplay too much?

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well, yes spobs should have gravity, they did in epsilon.

Anyway, for the propulsion argument, remember E=mc^2, in other words, the ammount of additional energy required to change momentum is equal to the mass times light speed times light speed again. So, although you can keep accelerating, it's going to take more and more energy, as your thrusters must ADD the value of E to themselves each time.

Isnt physics fun?

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--blackhole

(url="http://"mailto:blackhole@mac.com")mailto:blackhole@mac.com(/url)blackhole@mac.com

Spöps having gravity would be great, especially if you could orbit (maybe you'd have to be in a close, stabel orbit to get land?). I think it'd be especially great for combat. You could use your orbit to keep you moving while being able to focus on aiming you ship on the enemy (if you're using forward firing weapons). Or you could lure your enemy into it to slow him down and make him a better target. Or if you were really good, you could use it to accelerate you (like in the voyager fly-bys of the planets) though that might involve extra programming. Or etc...

I think maybe relativistic accelration (like blackhole said) where there is no top speed (well, besides light speed, though you could get closer and closer), just mass and acceleration would be cool. Lower accel/heavier ship could reach the same % of lightspeed as smaller/faster accelerating ships, it'd just take them a lot longer to get there.

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-NY Times Magazine

"Some people call magazines mags, some call 'em zines, so I just call them gazs."

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I played around with relativistic settings and it sorta sucks. After a while you can't tell where you're going, how fast or anything. The starfield blurs into nothing.

What if there were another limiting factor though. Right now, I've got a system density field in there. This is used to calculate how much friction the ship experiences (based on it's top speed field). Or not, I should upload a version using the relativistic code for you guys to play around with...

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Make speed caps high, but make ship shields begine to drain at certain speeds and acceleration slow in comparisson to the rop speed with out shield drain. You can also make thrust drain fuel very slowely as well, so ultimately you will either run out of shields or fuel. So two controls on the ship should be for removing the first speed lock, which keeps you from going fast enough to drain your shields, and the second is to keep you from draining them enough for it to counter ballance the recharge. Do you have a web page for this?

-Walter-

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No, I don't really have a web page dedicated to this (I've been spending almost all my available time coding...) It would probably be a good idea to set something up some time though, just a page to keep track of all the implemented vs proposed features in order to see how fast developement is going.

Anyways, as promised, I've UL'd two versions: one using the proposed Einsteinian physics model, and the other using the old Newtonian model. I haven't bothered to put anything in HTML since having two seemingly similar versions will most likely confuse anyone who doesn't read this...

Try both out, see how they feel. Try and catch the other ships to get a feel for how much control you have.

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In response to the new build, build 4 feels much better and smoother than the b5. I noticed a slight fps drop. The new physics are quite realistic, but I much prefer the old ones (Newtonian I believe).

I really like the parallax scrolling stars; they give a much stronger 3d feel than EV/O has. What about a foreground star layer (ie, one that scrolls faster than the ships do?

I can't really tell the difference between the Einsteinian and Newtonian models. I really liked build 4, but in both build 5 versions, the acceleration feels really sluggish (like flying a UE freighter or something ). Could you do a build with a slightly higher acceleration constant or something?

Keep up the good work!

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If a little knowledge is dangerous, where is the man who has so much as to be out of danger? - T.H. Huxley

I love this build! Especially the parallax starfield, hell, that's better than that of Ares! But what's the difference between the Newtonian and Einsteinian builds? They appear exactly the same

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OpenGL Avara!

AIM: EVAndrewM

"I haven't seen myself lately, AndrewM."
 GreenYO, #ev

The newtonian build is the same as EV/EVO. It uses simply acceleration and top speed. The Einsteinian model is:

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**< snip> ... I think maybe relativistic accelration (like blackhole said) where there is no top speed (well, besides light speed, though you could get closer and closer), just mass and acceleration would be cool. Lower accel/heavier ship could reach the same % of lightspeed as smaller/faster accelerating ships, it'd just take them a lot longer to get there.

**

Basically, there is no real top speed for each individual ship. I should also add a key to adjust the mass of the ship... (w/o having to use relativistic effects ;)) The Newtonian build is the exact same as build 4 with a small bug fix, and adding in a reverse targetting key. I'll check on the fps drop though... That could easily cause the sluggish ship problem.

Make sure you tell me which version you prefer. If everyone here likes Build 4 (classic EV) then I'll go with the newtonian model. Also, does everyone want the game panel in the same place? (top right of the screen, vertical)

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I'm afraid you've got your theorems seriously garbled. Newtonian motion has no top speed whatsoever. All motion thereof is relative. I suggest you review Newton's laws. The idea of a top speed is simply something that was implemented by `Syntax to prevent gameplay insanity. There is no scientific theory supporting it. A Newtonian model works at low relativistic velocities, not approaching anywhere near c (lightspeed). The 'Einsteinian' model, aka Special Relativity, is necessary for velocities approaching c. Basically, and I don't entirely understand it myself, if two objects are moving away from a stationary object (though stationary objects are something of a joke) in opposite directions at velocities of c with respect to the stationary object, their velocities relative to each other will not exceed c. Basically, it says that c + c = c. As opposed to the normal model of additive velocities (Newtonian), where an object moving away from a stationary object at 20 m/s, while another moves away from the stationary object in the opposite direction at 20 m/s, their relative velocities will be 40 m/s away from each other. Or, 20 + 20 = 40. In the model of special relativity, this value will be slightly less than 40, but at these relative speeds, the difference is not measurable.

As far as a practical model for gameplay motion, I would recommend a curve, where a frictional value degrades acceleration on the object with greater intensity as speed increases. In this model, a top speed will never be acheived, but a practical upper limit will never be exceeded by any significant amount.

I hope this clarifies things. Anybody that was under other impressions concerning motion should probably find a Grade 12 level physics text and read it carefully.

Chris Burns

I think I speak for pretty much everyone here... We're more than aware of all of Newtons laws. It's just so rediculous to have a system that allows infinate speed that we all take it for granted that there WILL be an artificial top speed limit.

That dealt with, there are a series of lemma's that deal with Einsteins theories. Among them are two of note, time and length dilations which account for the noted inconsistancies in your examples.

Your suggestion is a good one, though. It would reduce the amount of energy needed (thus time spent holding down acceleration keys) a great deal when trying to maneuver at high speeds.

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Ships are in a vacume, aka space. That applys a great deal of pressure on the ship, and it's pulling out.

Doing tight manouvers at high speed apply more pressure, and less constant pressure at that.

Due to these facts, it is less safe for ships to exceede a certain design limits.

However, it'd rock if there were outfits to remove the limit.

Going over the 'safe speed' would start hurting your 'Hull Integrety', displayed in a bar similar to the sheild/armor rating.

Taking shots with sheilds down, tight turns, and sudden changes of speed would all damadge the integrety, and all with varying amounts.

The armor, however, would be TOTALLY seperate.

One is the sturdyness of your ship, aka structure integrety, the other is the armor plating on the ship.

Granted, if you have 0 structInteg or armor, the ship would die.

Also, a speedomitor would be nice, something showing how fast relitive to a star you're going.

A meter showing the acceleration would be nice, too..

How's that sound?

-Skunks

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Enginners can actually hear machines talk to them. The rattle in the car's engine teases softly, "I'll bet you can't find me." The computer hums an approving tune when the enginner writes an expecially briliant peice of computer code. The toaster says "Not yet, not yet, not yet." untill the toast pops out. An enginner who is surrounded by machines is never lonly and never judged by apperance. These are friends.

To be honest, I hadn't even considered hull integrity yet. Damaging your ship with dangerous maneuvering, large gravitational forces, ... This is almost getting into the realm of locational damage.

Do people want locational damage? If you do, then what systems should be vulnerable? Shields, Armor, Engines, Sensors, Hull (integrety), Radar, Cloak (if present), ...?

I've posted a new build, available at the same place as always.

(This message has been edited by kberg (edited 05-22-2000).)