If my memory serves me right, I-War had a very different approach to shielding. The ships had, say, a shield generator which worked all over the surface of the ship, but that shield generator could only deflect one hit once every while, or it could only deflect hits on one side of the ship and then it had to wait until it could deflect hits on the other side - not sure anymore.

This could create really neat tactics when some fighter ships ''deflect'' the shields of a big capital ship in one direction while the bombers make a run on the other side Waddayathink?

For large ships, I like Shadow Mint''s idea. And making the larger mesh might not be too bad - you just have to scale the normal mesh (unless you want to reduce complexity to make collisions easier). Although I''d want to have a different section of shield mesh assigned to each generator.

For small fighters, I think the ellipsoid is best though, with layering for multiple generators.

You can use the same graphics for both of them though - wireframe, or just translucent colouring on the mesh. If possible, I think it''s best to make only the part of the shield that was hit go visible (not the whole mesh).

If you know what the modern Star Trek shields look like, then for fighters it''d look something like that, and for large ships it''d look the same except a different shape of shield.

John B

quote: Original post by TerranFury
Each shield generator emits a field according to an inverse square function. The force field at a given point is given by the sum of all individual fields.

Exactly. Although I would consider taking this a little further, so that for each generator there are two parameters: total field power, and a drop-off factor. They perhaps are not the best words to use, but this is what I mean. Rather than have a fixed function like the inverse square function mentioned by TerranFury, turn the "power of 2" into "power of x", where x can be adjusted to some degree. The adjustment could be made by the player during the game, or it could be fixed by the fictional "manufacturer" of the generator. So for a given amount of power going into the generator, you can either have a small tight field, where the field strength at any point is very high, or you can spread it out over a larger area, at the cost of field strength. If you also allow the player to control the power going into the generator, then there can be many ways for the shields to be configured, even when the number and placement of generators are fixed.

quote: Original post by TerranFury
It''s like the shield is a cloud, and weapon shots "carve out" this cloud; the shot and the shield neutralize each other. The outer, thin areas of the cloud do less to neutralize shots than the inner areas, but all areas affect the shot as it moves through them. More poweful shots get further into the cloud. If the shot is powerful enough to "tunnel" all the way through the cloud to reach the ship, then the ship is hit.

I think an easier and more realistic way would be to calculate the difference between the weapon power and field strength at the moment the shot reaches the "surface" of the metaball group, and adjust the power of both shot and shield at that time. If the shot has enough energy left, then simply let it through, if not, it gets blocked. Either way the power drain to the sheilds is rationed out to all the generators that have an effect at that location, and the whole field is diminished then, rather than creating a tunnel through it.

quote: Original post by Plasmadog
Exactly. Although I would consider taking this a little further, so that for each generator there are two parameters: total field power, and a drop-off factor.

I like that idea.

quote: Original post by PlasmaDog
I think an easier and more realistic way would be to calculate the difference between the weapon power and field strength at the moment the shot reaches the "surface" of the metaball group, and adjust the power of both shot and shield at that time. If the shot has enough energy left, then simply let it through, if not, it gets blocked. Either way the power drain to the sheilds is rationed out to all the generators that have an effect at that location, and the whole field is diminished then, rather than creating a tunnel through it.

By surface I assume you mean there would be a threshold level between solid shield and empty space, with no cloudy areas in-between. This has some advantages and some disadvantages. First, the pros: It would perhaps be a little easier to calculate (though you'd probably still have to store the scalar field, so the memory requirements wouldn't drop). Also, as a concept, it's something gamers are more familiar with. In addition, it makes visualization easy; just use the marching cubes algorithm. On the down side, though, it's just not as cool as mine!


[edited by - TerranFury on April 1, 2002 10:18:55 AM]

quote: Original post by cearny
If my memory serves me right, I-War had a very different approach to shielding. The ships had, say, a shield generator which worked all over the surface of the ship, but that shield generator could only deflect one hit once every while, or it could only deflect hits on one side of the ship and then it had to wait until it could deflect hits on the other side - not sure anymore.

Your memory serves you well - in I-War and Edge Of Chaos (I-War 2) shields don't enclose the whole ship in a bubble, but only block shots from a particular direction. The shield generator can rotate to place the shield over any part of the ship, except the main thrusters.

That meant that if you ganged up and hit the enemy from three different directions at once, one of the shots was guaranteed to get through. It also made you try to get behind the enemy because they were unshielded there. IMHO, it worked quite well.

[edited by - Krunk on April 1, 2002 11:14:41 AM]

Err... Just to be an annoying prick...

THE ENTIRE POINT OF ATTACKING CAPITAL SHIPS WITH FIGHTERS IS TO GET INSIDE THE SHIELDS

Okay, that is my statement, after watching way too much startrek and such ^_^

Capital Ships are big enough to sport such big armor platings that normal fighters can''t do any serious damage. All they *can* do is take out smaller weapon arrays, so that the bombers stand a chance of surviving long enough to land a lucky hit on stronger targets (shield generators, bigger weapon arrays, etc. etc.) The bigger bombers then try to weaken the shields.

Meanwhile, the smaller guns on a capital ship gun at the Bombers and the bigger Frigates/Corvettes. Fighters are usually ignored by capital ships.

Capital ships *do* have shields though. Because they can sport enormous beam weapons against each other, they *have* to get a defense against that as well. Huge circular shields work best. The way to take out these shields is either to keep blasting away with HUGE beams ''till the shields are depleted. Or send in the smaller fighters and bombers to take out the short range weapons, so that you can get a corvette in to destroy the shield generator.

Shields are big circles, the bigger the cap-ship, the bigger the shield. The entire point of shields is to eliminate enemy fire. So, when you got 2 fleets battling each other, you probably got a big carrier on both sides with huge shields. That is where the bombers hide, and the "repair ships". Then you get Cruisers, that also sport huge shields. They are the ones that provide cover for fighters. Then you got Corvettes/Frigates. Still big, a lot of guns, though lesser shields. And just about the only type of shield that a fighter can harm. They are the dudes that go inside enemy shields to take out fighters and shield generators. And the small fighters/bombers? No shields at all. Simply there to kill other fighters/bombers.

And the real fun is when a cap. ship loses it shields. Suddenly, the enemy capital ships can start gunning down all the fighters that are hiding in there, and they can blast away at cargo ships.

...

...

Damn, this is really off-topic I think! Erm... Circular shields, where moer generators -> more power.

Right... Went to do something... err... important... :D and came up with another idea perhaps.

Expand the mesh of the ship outwards, to generate the shield. Then, when it gets hit somewhere, it "dents in" towards the "real" position of the vertex. Once it is completely dented (it hits the original point, ie. the armor plating) the ship will take normal damage there.

The amount of "dent" per hit will off course depend on the strenght of the weapon, and the strenght of the shields, but also of the *distance* to the nearest shield generator. Or rather, what shield generator has the most effect on it (per point, based on the strenght and distance to each shield generator. Perhaps come up with a simple law that dictates how fast the influence of a generator weakens over distance, and give it a cool name ).

Anyway, there would be one special button, "power-up shield". That would immediatly deplete some sort of energy reserve, and every generator would start to push against the mesh of the ship, expanding it greatly, and generating the shield mesh. (either the entire ship model is used, or a special, custom mesh) The generators then kick in to keep the integrity intact. Come up with some sort of "inward force" that the mesh will force onto the generators. Then, because of that inward force, and distance to the generators, the shield will immediatly begin to collapse. However, because of the strenght of the generators, each "vertex" of the shield mesh will stabelize at some point, because the closer it gets to a generator the greater the "outward" force that counters it. Now, when a "vertex" gets hit, the amount of force it gives increases, and it moves inwards ''till the generator can counter it enough.

Now, the effect of sending extra power to a generator would be increased force at that point, so it would start to push away the mesh again. When a generator failes, it completely quits sending force, so a large part of the shield would collapse, though at some point the other generator''s fields would "catch" it, hopefully before it reaches the hull (reaching the hull == no more shield there).

And it takes time to refill the original "shield burst". When it is filled again, you can refire it. That would then give a big extra value to every "vertex" of the shield, causing it to return to normal.

So, a really smart captain would buy a second energy array, so that he can refire his shields during battle ^_^

I like that idea, you could use a radial projection of the dents:

struct dent{
vector vDirection;
float fDepth;
}

So whenever an object (projectile/whatever) strikes the shield, the location of it''s intersection is determined, and the shield is bent inwards there. Over time, the fDepth of the dent will slowly decrease until it dissapears.

George D. Filiotis
Are you in support of the ban of Dihydrogen Monoxide? You should be!

The "dent" idea is pretty cool. Somehow I doubt it''s scientifically plausible, but that doesn''t really matter. What''s important in an idea like this is that (A)It''s cool/original and (B)It works. I think your idea does both of those things wonderfully.

One small concern I have, however, is with the fact that ships are not regularly subdivided. The effect of a "dent" on the ship ends up having as much to do with geometric complexity at a given area as anything else. The effect is far from uniform. I''m not sure if that matters.

Oh yeah, one final big plus to the polygon-offset shield is that it''s VERY easy to render - much more so than my NURBS.

quote: THE ENTIRE POINT OF ATTACKING CAPITAL SHIPS WITH FIGHTERS IS TO GET INSIDE THE SHIELDS

Not necessarily. In many games/movies/whatever, the advantage of using fighters is that the turrets of capital ships are often designed for shooting large distant targets, and therefore can''t track fast enough to shoot at fast moving fighters.