Sign in to follow this  
Anthlon

Extend the physics distance in atmosphere

Recommended Posts

I have observed this a long time ago, never has any issue with that, but now, it realy made me mad!

Situation:

- I made a flight to a lower orbit

- early situation in career = no other on-orbit power sources + engine with no power supply

-> fuel+energy empty craft orbiting kerbin stuck there (with 1 crew in it)

- rescue mission type to meet at orbit, than gently touch "dead ship" and retrograde burn holding dead one until safe deorbit trajectory

this was the situation after burn:

kerbal_stouchana3.png

Situation after:

I did after retro-burn, another burn detached from dead one to regain some speed/alt to make difference of landing, rescue ship was supposed to land a lot later (far from dead one), parachutes on both ships already activated+gear extended for case landing to a land

Problem:

If you are going down, the ship which you do not watch (piloting/flying) will disappear killing the crew.

I did immediately after landing recover of watched ship, and other one (withl longer landing trajectory) was not even seen at tracking station, also no debris from it of any kind.

Killed crew, now in list KIA.

FIX THAT!

Edited by Anthlon
corrections

Share this post


Link to post
Share on other sites

But then it would have to simulate physics, all the way down. That would mean every everything that ever is in the atmosphere when you are not there would have to be simulated. This would likely cause problems.

Share this post


Link to post
Share on other sites

There is a mod so you can extend how far out the physics work. Defualt is 2.5km I know some people have tride for fun 50+ km.

Share this post


Link to post
Share on other sites

Yep this has been discussed many times and always comes back to needing to simulate physics for multiple craft at once which would be a large performance hit. Easiest solution is instead of recovering the craft just recover the kerbal. He can take any science he gathered anyway.

Share this post


Link to post
Share on other sites
Yep this has been discussed many times and always comes back to needing to simulate physics for multiple craft at once which would be a large performance hit. Easiest solution is instead of recovering the craft just recover the kerbal. He can take any science he gathered anyway.

It is! but there should be some solution, also for droping (recovering) stages, something like preloaded result for object of some conditions. Like with or without parachute activated etc.. I personaly do not need exact simulation on non-watched crafts/debris..

Lets say, if it has parachute, than place it on surface of projected land, or sea, if it has not, then crash it (erase).

Edited by Anthlon
advance

Share this post


Link to post
Share on other sites

My first reaction was "It's always been like that, what are you complaining about?" but on second thoughts I think you're right - it is one of the big functional holes in KSP that we have to hope will be addressed during beta. We do know Squad intend to address the aerodynamics, so perhaps while they're working on that they can look at recovering 'stages' through atmosphere.

Share this post


Link to post
Share on other sites
There is a mod so you can extend how far out the physics work. Defualt is 2.5km I know some people have tride for fun 50+ km.

Please tell me the name of this mod, as i very much would like to play with something like that.

- - - Updated - - -

But then it would have to simulate physics, all the way down. That would mean every everything that ever is in the atmosphere when you are not there would have to be simulated. This would likely cause problems.

Does not have to be everything. Just letting us choose which crafts to enable physics on would be enough.

Share this post


Link to post
Share on other sites
Here is a better mod for this issue than extending the physics range, which takes into account parachutes and crap.

Share this post


Link to post
Share on other sites

Actually, if you de-orbit those 2 ships just like it shown in the picture, without separating them, both of them could survive. They are unlikely to get 2.5km away from each other during the re-entry.

Share this post


Link to post
Share on other sites
My first reaction was "It's always been like that, what are you complaining about?" but on second thoughts I think you're right - it is one of the big functional holes in KSP that we have to hope will be addressed during beta. We do know Squad intend to address the aerodynamics, so perhaps while they're working on that they can look at recovering 'stages' through atmosphere.

The biggest issue is with Unity, not Squad. It's how Unity handles the physics simulation. All the calculations are done single-core, and while the original example of 2 tiny ships in-atmos isn't a huge issue, many-multiple stages with many multiple parts, all with their own trajectories, drags, joint stresses, etc. creates exponential computation. All on a single core. I mean the game already is pretty damn laggy.

That said, the [long-running] rumour is Unity 5 will have more multi-core options, giving Squad more options when it comes to how the physics are handled, and Squad's eager to jump on it. It was supposed to be available in beta around this time(?) but we haven't heard anything so I assume Squad hasn't got its hands on it yet.

I mean with the engine we have the solution to OP's mission (at least going by his screenshot) would've been to've sent up a probe ship with an empty pod and rescued only the stranded astronaut. That or roll the dice on having both ships de-orbit together (maybe he can tangle their landing legs on the way down?) and fire the chutes as close to the same time as he can, and hope they stay within the 2.5km sphere. I think he can still deploy chutes and raise their deployment height without power, so I think the de-orbit shouldn't be too far before they deploy and then they should stay pretty close to one-another.

Edited by Franklin

Share this post


Link to post
Share on other sites
But then it would have to simulate physics, all the way down. That would mean every everything that ever is in the atmosphere when you are not there would have to be simulated. This would likely cause problems.

I don't really think so.

When you have a craft landed, it's probably a good idea not to load that (unless it's near a loaded craft).

Besides, how many spacecraft would you have in the air at a time?

Share this post


Link to post
Share on other sites
I don't really think so.

When you have a craft landed, it's probably a good idea not to load that (unless it's near a loaded craft).

Besides, how many spacecraft would you have in the air at a time?

Depends, are you working with a mod that takes advantage of satellite networks? http://i.imgur.com/p0hlg41.jpg

But the physics "sphere" isn't about on land, or in an atmosphere or anything like that. Just distance from the active ship. So really you're just asking to make the physics "sphere" [much] larger, which can capture many, many ships for a number of players.

Essentially anything outside the active ship's physics sphere is put "on rails" in that it's physicsless, but will maintain the trajectory it held at the time it was put on rails. If that trajectory was an orbit, it'll remain in orbit. If that trajectory was a de-orbit, it'll "crash" (be removed by the simulation).

Share this post


Link to post
Share on other sites

I'll admit before part costs were introduced, this was an afterthought, but now we have the issue of being unable to recover dropped stages. Hopefully Squad does address this, because dropped stages are expensive when you can't recover a single one. It's one thing to want to simultaneously de-orbit two ships, that doesn't happen often, but to want to attach chutes to a dropped tank? It happens all the time.

Share this post


Link to post
Share on other sites
Depends, are you working with a mod that takes advantage of satellite networks? http://i.imgur.com/p0hlg41.jpg

But the physics "sphere" isn't about on land, or in an atmosphere or anything like that. Just distance from the active ship. So really you're just asking to make the physics "sphere" [much] larger, which can capture many, many ships for a number of players.

Essentially anything outside the active ship's physics sphere is put "on rails" in that it's physicsless, but will maintain the trajectory it held at the time it was put on rails. If that trajectory was an orbit, it'll remain in orbit. If that trajectory was a de-orbit, it'll "crash" (be removed by the simulation).

What I had in mind was that there would be multiple spheres of physics loading, so satellites wouldn't have to load.

Share this post


Link to post
Share on other sites

Stage recovery should address this problem, granted the parachute is already staged when you push it into the atmosphere.

Share this post


Link to post
Share on other sites

Normaly when I need to send a ship to push another out of orbit and I want to recover both I have the pusher ship give just enough of a nudge to put the dead ship into atmosphere and then it backs off and thrusts back into a stable orbit while I ride the deadship down. I deorbit the pusher ship after the first one touches down. Technicly you dont even need a stable orbit for the pusher ship, just one that stays above 30km or so and ensure it will be out side of physics before you hit the atmosphere. Its orbit wont decay when its on rails and ships dont deleate till they get into the low 20s of KM

Share this post


Link to post
Share on other sites

1 - Download "Stage Recovery"

1a - install "Stage Recovery"

2 - apply parachutes liberally (or RealChutes) or leave enough fuel for a powered suicide burn landing

3 - watch as a clever kerbal keeps most of your things intact and returns them to KSC

4 - Profit (literally)

Share this post


Link to post
Share on other sites

I think it's the LazorSystems mod or seomthing that increases physics range? max is still only 7.5 km or so though, so you can run into the same problem even with that!

As others have stated, either landing them both together would work (I have an old ship up on the rocketbuilders forum that would happily take 3 Kerbals to LKO, then perform a bit of an aerial ballet with all 3 pods seperating and drifting down on their own 'chutes - this works as they stay within the 2.5km default range) or making sure your pusher-ship gets back into a semi-stable orbit above 30km before switching back to the craft that is landing/returning.

Share this post


Link to post
Share on other sites

+1 I really want something like this implemented into the stock game.

Tip: if you land both craft together, you can maintain physics on both. Just hit the parachute button on both and keep them close together, and they'll parachute at the same time and land right next to each other.

Sometimes the aerodynamic physics fails on one, but all you have to do is switch back and forth with the ] key. If the one you don't have focused starts pulling ahead like the air isn't slowing it, just swap to it.

Share this post


Link to post
Share on other sites

Thanks for replies, i see the problem now, how it is set up at this current state. No serious complaints to squad, they are making a hell good job, from nothing we have good game.

Now to my suggestion, as been said here. Same for (my ship, but also for everyone)

-separating somewhere where is debris falling down, can we have something like simple impact calculator? By that i mean - If its falling, lets have crash it to projected XY surface, if it has parachute lets have it land as a "landed" debris for all that things we do have disappearing now. Possible in game as it is now? Really, why to lose time and money (in game) with stage parachutes for smooth drop, and not just bomb KSC with falling boosters straight down..which are never land/impact to ground

Share this post


Link to post
Share on other sites

Here's an idea for the solution: Targeted ships could be set to stay in physics range.

Share this post


Link to post
Share on other sites
Here's an idea for the solution: Targeted ships could be set to stay in physics range.

This probably concludes all possible situations in best way. +1 for this..

Share this post


Link to post
Share on other sites
This thread is quite old. Please consider starting a new thread rather than reviving this one.

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Sign in to follow this