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Ship Bumping? Still needed?
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Lexar Mundi
Imperial Shipment
Amarr Empire
#101 - 2012-10-09 03:36:23 UTC
Seminole Sun wrote:
This (somewhat ridiculous) mini-threadnought eventually raised a good question (somewhere around page 8 if you're interested)

https://forums.eveonline.com/default.aspx?g=posts&t=155027&find=unread

And that is, is there a valid reason to have ship bumping in the game?

My concern/issue/problem is that it is an absolutely riskless activity with no consequences and no correspondingly cheap counter. Sure, I can shoot the guy, but in hi-sec that incurs a lost ship and a security status penalty (not to mention, if I can kill him inside 20 seconds I almost certainly lost a lot more valuable ship than he had). As a result, it strikes me as very nearly the definition of griefing. Leaving aside the issue of ganking, it's just someone causing problems for which there's no rational, reasonable solution.


There was a time when titan bumping was the only form of tackling with subcaps. With heavy interdictors, that's not the case any more.

So does this relic have a place any longer?

bumping can still be used to knock people away from stations, therefor it is still needed.

/end thread.
Magnulf
Wormholers Anonymous
#102 - 2012-10-09 12:04:36 UTC
Veryez wrote:
Immortis Vexx wrote:


....Stuff....



Someone needs to re-open their kinematics textbook I see… What you have is kinematics problem, and while you could figure this out with forces (since we are working with elastic collisions), you can’t the way you’re trying to do it (using velocity instead of acceleration). The easiest way to do this is to use conservation of momentum. To simplify the equation, we’ll assume that the frigate transfers all of its energy to the freighter (thus frigate final velocity = 0). Therefore:

M1V1 + M2V2 = M1V3 + M2V4

Where M1 = Freighter Mass
M2 = Frigate Mass
V1 = Initial Freighter Velocity
V2 = Initial Frigate Velocity
V3 = Final Freighter Velocity
V4 = Final Frigate Velocity

Velocity is of course a vector, so to simplify our calculation, we’ll assume a perpendicular collision (i.e. the freighter is moving perpendicular to the frigate). Therefore V1 = 0 and V4 = 0 (remember we’re dealing with vectors, and I assumed complete energy transfer).

Using numbers for an ibis (with a MWD) and a charon, I used 960 e6 for M1, 1.663 e6 for M1 (the MWD raises mass by 500000) and 2448 m/s for V2.

Solving for V3, I get 4.24 m/s (this would be the Freighter's velocity in the initial frigate’s direction). For those who want the full challenge (i.e. the Frigate doesn’t completely transfer all it’s energy, you will need to solve for V3 in relation to V4 in the conservation of Momentum equation and plug it into the Conservation of Energy equation and solve the polynomial equation – have fun). However in that case, the angle changed would only be smaller.

In other words the freighter will be knocked off course by 3.733 degrees. Which considering the number of times I’ve warped sideways, probably really isn’t enough to prevent a warp.


i.e. Bumping in EvE has nothing to do with real life physics....


No offense, but I think you need to reopen your textbook as well :) The kinetic energy is 1/2*mass*velocity squared. In other words your equation should be:

m1v1^2 + m2v2^2 = m1v3^2 + m2v4^2

which, if solved for v3, gives:

v3 = square root ( m2/m1 * v2^2)

v3 = square root ( 1.663/960 * 2448^2) = 101.9 m/s
Pipa Porto
#103 - 2012-10-09 13:16:15 UTC
Magnulf wrote:
Veryez wrote:
The easiest way to do this is to use conservation of momentum.


No offense, but I think you need to reopen your textbook as well :) The kinetic energy is 1/2*mass*velocity squared. In other words your equation should be:

m1v1^2 + m2v2^2 = m1v3^2 + m2v4^2

which, if solved for v3, gives:

v3 = square root ( m2/m1 * v2^2)

v3 = square root ( 1.663/960 * 2448^2) = 101.9 m/s



Just to point out, you can (and Veryez did) do this using Momentum instead of Kinetic Energy.

Just assume that the collision is perfectly elastic, use the right frame of reference, and you can safely ignore Kinetic Energy.


Assume the Freighter is moving at 93.8m/s (all 5s Charon) and masses 960Mkg, and the SFI is moving -19k m/s (I can post the fit, if you want) in the direction of the freighter's travel (negative of course indicating that it is actually moving towards the freighter head on) and masses 60Mkg (100mn MWDs add a lot of mass). First, we'll change the reference frame to one where the Freighter is sitting still (add a constant of -93.8m/s to all velocities).

v1 is post-collision Freighter, v2 is post-collision SFI. u is pre-collision velocity, and m is mass, 1s and 2s accordingly.

v1= [u1*(m1-m2)+2m2u2]/(m1+m2)
v1=[0*(whatever)+2(60)(-19000)]/(960+60)

v1=-2,235m/s

v2=[u2*(m2-m1)+2m1u1]/(m1+m2)
v2=[-19000*(60-960)+2(960)(0)]/(960+60)

v2=16,764m/s

In other words, the Freighter gets bumped crazily off backwards from its direction of travel and the SFI gets bumped crazily off backwards from its direction of travel.

I can also do the math for a perfectly inelastic linear collision for you.

v=[m1u1+m2u2]/(m1+m2)
v=[960*0+(60*-19000)]/(960+60)

v=-1117m/s

In other words, both masses are moving backwards from the Freighter's direction of travel.


Now, as we know, the magnitude of these speeds is more than what we see in the game, owing to the effects of continuing acceleration, the fact that Space is a viscous liquid, and my guess that the collisions are not perfectly elastic. But the fact that Bumping by relatively small, extremely fast ships results in big ships moving at dizzying speeds is not surprising. Newtonian Physics predicts it.


If you want to do 2 or 3 dimensional or partially elastic collisions, feel free.

EvE: Everyone vs Everyone

-RubyPorto
Backfyre
Hohmann Transfer
#104 - 2012-10-09 15:13:35 UTC
Cephelange du'Krevviq wrote:


F = ma

Irony is ironic; are you forgetting that frigate, if traveling at several thousand meters per second transfers a lot more energy/force to the target than its basic mass would suggest? There's also little to no friction in the near-vacuum of space, so each vessel should bounce off in appropriate directions and at appropriate velocities.

Technically, collisions are based upon conservation of momentum (m v) and conservation of energy (1/2 m v^2)... Better physics would be a plus. You could then have freighters bumping cruisers...

Dread Pirate Pete wrote:
If you are harassed by a bumper (who is in a cheap insured ship in a undecable npc corp) you can't do nothing of real value to defend yourself. Neither can your friends. All you can do is hope you have more patience than he does, which is not the best game mechanic.


Not entirely true. Have a friend double web your freighter to get it aligned much faster.

Have a friend bump the bumper.

For miners, try a tight orbit around the rock or a can to make it harder on the bumper.

Bumping has evolved as a hack tactic to counter a lot of poorly designed game mechanics. It is needed until all the other stuff is fixed.
Krakhen
Praetors of Orpheus
#105 - 2012-10-11 19:25:12 UTC
Bumping is a result of limited gameplay mechanics. I hope it gets replaced by collision one day. Or maybe they could replace the vast vaccum with water, then it would be sensible. Roll
Nyla Skin
Caldari Provisions
Caldari State
#106 - 2012-10-11 20:07:31 UTC
Seminole Sun wrote:

And that is, is there a valid reason to have ship bumping in the game?


As long as theres stations and stargates, there wil be ship bumping.

In after the lock :P   - CCP Falcon www.nizkor.org/features/fallacies
Katran Luftschreck
Royal Ammatar Engineering Corps
#107 - 2012-10-11 20:52:00 UTC
Praxis Ginimic wrote:
I would LOVE to see a collision mechanic in place. If a heavy armored cruiser bumps a mining rig at top speed then mass amounts of damage to miner. If a nano frig bumps a freighter the frig just pops. Im not gonna pretend to have thought through this at all but it would be cool. Maybe a ramming speed mod...reinforced prow for tearing through enemy hulls. And 'cause it causes damage you can shoot back. It could still effect speed and trajectory to continue to be used as it is now



Auguror: 10,730,000kg

Hulk: 40,000,000kg

Laws of physics says that it is the cruiser that would suffer more damage. Almost four times as much, in fact. So by all means, go for it. The miners will be the one's laughing at the end of the day.


Oh, and freighter bumping with realistic physics? I'd love to see it, actually...

Maelstrom: 103,600,000kg

Charon: 960,000,000kg


I'd love to see realistic collision physics. People would become terrified of freighters.







http://youtu.be/t0q2F8NsYQ0
CorInaXeraL
The Dresdeneers
#108 - 2012-10-11 20:57:26 UTC
Katran Luftschreck wrote:
Praxis Ginimic wrote:
I would LOVE to see a collision mechanic in place. If a heavy armored cruiser bumps a mining rig at top speed then mass amounts of damage to miner. If a nano frig bumps a freighter the frig just pops. Im not gonna pretend to have thought through this at all but it would be cool. Maybe a ramming speed mod...reinforced prow for tearing through enemy hulls. And 'cause it causes damage you can shoot back. It could still effect speed and trajectory to continue to be used as it is now



I'd love to see realistic collision physics. People would become terrified of freighters.



I would park salvage ships outside of Jita 4-4.