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Engine-Kill drifting problem

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Post Sat Oct 09, 2004 11:12 am

Engine-Kill drifting problem

Hey guys, I haven't been here in a while; danged school has sucked time right out the window
But I have managed to satiate my thirst for FL by slipping in a few hours here and there
I tried a recently-released mod (ReBalance v3.5) which I worked on with MD for a long time this summer. However, he seems to have slipped in a little thing somewhere that is driving me absolutley INSANE : whenever you hit the Engine-kill key (say when you are going 550 m/s in Cruise), your ship just drfits to a complete stop (to 0 m/s) in about 3 seconds -- there is no realistic momentum or inertia in this, and it makes dogfighting unbelievably hard, frustrating, and retarded. It's so unrealistic and damned annoying that I am about to kick my comp

Could anyone tell me what file(s) that would allow for this type of thing? Would this change be in constants.ini, engine_equip.ini, or some other file?
Thanks so much; I just can't friggin play with this unrealistic and stupid movement-cap.

"Do you see the slightest evidence anywhere out there that man was the climax towards which creation had been straining from the beginning? That creation came to a screeching halt with the birth of man?"
- Ishmael

Edited by - Ro9ue on 10/10/2004 12:35:55 PM

Dev

Post Sat Oct 09, 2004 2:31 pm

Well, without looking at the .ini files for the mod I can't tell you for certain. HOWEVER, it sounds very much like the linear drag of the ship hulls is a large fraction of the linear drag of the engines. If you've never looked into how FL deals with linear movement, this will take some explanation, but it should answer your question completely (presuming I'm correct about the mod).

There are three things that affect your linear movement: thrust, linear drag, and mass. The thrust is provided by the ship's engine (and if you've activated one or more thrusters, those too; like drag and mass, thrust adds together). Linear drag is provided by the engine and the ship's hull. Mass is provided by the ship's hull as well as all the equipment mounted on the ship.

Increasing the thrust/linear drag ratio will increase your ship's top speed (indeed, the top speed exactly equals thrust/linear drag), while increasing the thrust/mass ratio will increase your ship's acceleration (from 0 m/s, the initial acceleration is exactly thrust/mass, though of course the acceleration must die off since the ship reaches a steady maximum velocity). Now, the reason why ships keep drifting when you hit engine kill in stock FL is this: the linear drag of all the fighter engines is always 599, while the linear drag of their hulls is always 1. When you kill the engines, you negate both the thrust AND the drag produced by the engines, thus making the deceleration of your ship very low (and expectedly, the greater the ship's mass the longer it will hold its velocity).

So, my guess is that much if not all of the linear drag on the ships of the mod in question is allocated to the hull rather than the engine. Thus, when you kill the engines, the total linear drag doesn't drop by a factor of 600 like you expect it to; it may only be halved or it might not even change at all. Since you've also lost all the thrust provided by the engines, you can expect your velocity to drop like a stone.

If you'd like to change things so that they are more to your liking, the files to mess with are data/equipment/engine_equip.ini and data/ships/shiparch.ini.

Post Sat Oct 09, 2004 3:33 pm

Check this out. This is a thread from bane42 dealing with everything concerning flight stats and some great explanations.

Post Sun Oct 10, 2004 11:34 am

Aha, ok. Those files and the coefficients were what I needed I can't wait to jump in and try out new values and constants - and regain my realistic engkill. I mean, who ever heard of a game in which you deactivated your main means of propulsion and then drifted to a stop -- in the vacuum of space for cryin' out loud! Ugh, that just really sent me. It's simply absurd.

Anyway, thanks for the explanation and the link. Great job, bane42 and Dev, for the exquisite explanations of flight dynamics I am itching to find some time to look in my files to find what the blazes that mod changed.

"Do you see the slightest evidence anywhere out there that man was the climax towards which creation had been straining from the beginning? That creation came to a screeching halt with the birth of man?"
- Ishmael

Edited by - Ro9ue on 10/10/2004 12:36:42 PM

Post Tue Nov 09, 2004 11:54 am

THANK GOD! I'm glad I'm not the only one who's had this problem!
anybody know how to pass it on to the mod makers? I'm not getting any response from them. this has been the only thing keeping me from playing this mod!

Post Tue Nov 09, 2004 12:04 pm

For a more complete- in my opinion, but it's backed up by mini-mods that demonstate all of the concepts- picture of how all of this works:

Click here to view my Physics article.

Dev's correct, but there is a nuance here. Basically, ships in the mod you're playing are halting super-fast because the ship's Linear_Drag has been tinkered with (I don't suggest this to modders, for reasons that are clear if you understand what that Linear_Drag is for).

What matters for slow/fast acceleration curves, as I showed in my article, is the relationship between Linear_Drag and Mass.

So, for example... in the mod you're talking about, if you want ships to slow down much more slowly on Engine_Kill events... simply up the ships' Masses by 3. This will NOT change the top speed of the ships, as my article explained, but it WILL affect handling aspects of the ship, including true turning behavior.

To see some pretty dramatic examples of this sort physics editing, download my mod, Warriors of the Sky, which you can find a download link for in the Mod Announcements forum.

Edited by - Argh on 11/9/2004 12:05:47 PM

Edited by - Argh on 11/9/2004 12:10:46 PM

Edited by - Argh on 11/9/2004 1:48:48 PM

Post Tue Nov 09, 2004 2:14 pm


Dev, you're incorrect, unfortunately. The Engine's Linear_Drag and Ship's Linear_Drag are basically the same thing, and ships that have a Linear_Drag of 0 can still drift to a halt very slowly, despite whatever's happening with the Engine.
Actually, that's not entirely correct. Engine kill does kill the engine's linear_drag, but it does not kill the ship's linear_drag. A ship with a linear_drag of 0 still slows down because of a setting in the constants.ini file.

Post Tue Nov 09, 2004 2:47 pm

Yes, I'd forgotten about DEFAULT_LINEAR_DAMPING, which in my mod is set to 0, along with DEFAULT_ANGULAR_DAMPING... I set them to zero to simplify getting control over the flight physics, and haven't seen a reason yet to turn them back on...

In my mod, all Linear_Drag handling is through the Engine file, not the ship. I mainly did this because was rather concerned about being able to insta-stop in various ways, and wanted to make sure that ships couldnt' do that. Same reasoning applied to linear_damping, etc.

Edited by - Argh on 11/9/2004 2:53:28 PM

Post Fri Nov 12, 2004 4:50 pm

"So, for example... in the mod you're talking about, if you want ships to slow down much more slowly on Engine_Kill events... simply up the ships' Masses by 3. This will NOT change the top speed of the ships, as my article explained, but it WILL affect handling aspects of the ship, including true turning behavior."

erm, is it possible to get some more specific info? what files to mess with and where exactly and how? would the mass have to be changed for each ship? what?

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