[1.12.X] RealChute Parachute Systems v1.4.8.3 | 24/01/21

[stupid_chris]

Oh! Now I finally get _exactly_ what you've been talking, sorry for slowpoking -_-"

I'll be very-very-very-very appreciated! Theoretically this is possible, as game always know where is CoM of the vessel you can cast a line from vessel CoM to chutes origin point and apply drag force in that direction ...I hope I do not disgrace myself because of this hypothesis, cause I'm not a programmer at all

Also, what if I weld chute directly into the pod? Theoretically will it apply force correctly since they become one part?

That will apply the force as if it was applied uniformly on all the parts welded together, yes. As for applying on the vessel, no need to do it this way, the parachute already has a position vector. I can direct it to the place where I want it to apply the force with this vector alone, it's just a matter of if the whole vessel deals well with forces applied on it.

[The Destroyer]

Congrats on the daily!

[stupid_chris]

Oh wow.

Necessary here.

But dayum, that will probably get some more folks around!

[KvickFlygarn87]

Grats on getting featured in Modding Monday!

[Deltac]

Hate to be a bugger, but what was the consensus reached between you and friz about the Fasa Gemini chutes?

[stupid_chris]

Hate to be a bugger, but what was the consensus reached between you and friz about the Fasa Gemini chutes?

For some reason the parachutes simply don't want to animate. I've been quite busy and I haven't had much time to figure out what is wrong, but it doesn't seem to be on Frizzank's side. I'm not quite sure what it can actually be.

[jrandom]

For some reason the parachutes simply don't want to animate. I've been quite busy and I haven't had much time to figure out what is wrong, but it doesn't seem to be on Frizzank's side. I'm not quite sure what it can actually be.

What difference is there, if any, between the animation for regular chutes and Frizzank's chutes? That might be a promising line of investigation.

[stupid_chris]

What difference is there, if any, between the animation for regular chutes and Frizzank's chutes? That might be a promising line of investigation.

I doubt there is any. I'll hve to look into it, but my guess is going more to why my plugin can't animate it and stock can.

[Aknar]

First of all, love your mod, hope what i'll say afterwards will be well received.

I don't really understand the decision to go for 50m main chutes. That really seems excessive, and yet the parachute has lost a lot of it's efficiency. We have to reason with Kerbal sizes 2x smaller and their environment which is 4x smaller. I hope the idea isn't to land a whole ship with all it's stages since the idea of staging is to keep only the stuff you need throughout the mission while getting rid of the rest as it becomes useless. Replacing the vanilla parachutes with stats of your own was a good move and I can't get why it has been undone. You obviously put loads of great and realistic new features into the new versions and this is probably more realistic but it seems to defeat the purpose of having several different types of parachutes and even a micro-burn to brake at the last second if there is a 50m parachute doing all the work for you and threatening to trap you under it you once it comes down. I'd envision the big ones to be the last solution for heavy crafts having to land on duna for example. Instead of one huge chute, you could easily fit in three small ones that would do the trick and look way cooler. About those, where are they? I can't get my hands on them and I suppose you need to change the whole part.cfg to avoid overlap, ... Even the ones that deploy two chutes overlap. That's a bit of a shame :/ The single chutes should be stored away in the stock parts that have a smaller profile (or a new part with the same profile). I'll try and play around with values until I get something I'm happy with but I'd be really greatful if you could give me the version you had after the major update to have the new features but before you changed the chute to 50m. If you don't have it anymore, could you tell me how to get those three parachutes that don't overlap? For now I'm using the drogue chutes for main chutes which is actually really fancy because it forces you to do a last-second burn to have a smooth landing

Edited December 10, 2013 by Aknar

[ZobrAA]

That will apply the force as if it was applied uniformly on all the parts welded together, yes. As for applying on the vessel, no need to do it this way, the parachute already has a position vector. I can direct it to the place where I want it to apply the force with this vector alone, it's just a matter of if the whole vessel deals well with forces applied on it.

So I weld SDHI chute into pod, and drag force vector seems now be applied correctly:

But what the heck with pod's mass now?! xD

Also look at mass of original SDHI_ParaDock_1_ClampOTron:

It seems this is a bug...

[AngelLestat]

The new shapes looks ugly, they are too big.

Also the menu part count is increased by a lot.

Why always modders dont take care of this issue.

There is a limit to the amount of parts that we can add to the game. Also the loading time increase, the game performance decrease and find a part in the menu selection between many is harder.

All these addoms would be great if they come in form of procedural parts. Snapping between standard sizes.

I will keep the old version of real parachutes.

[stupid_chris]

First of all, love your mod, hope what i'll say afterwards will be well received.

I don't really understand the decision to go for 50m main chutes. That really seems excessive, and yet the parachute has lost a lot of it's efficiency. We have to reason with Kerbal sizes 2x smaller and their environment which is 4x smaller. I hope the idea isn't to land a whole ship with all it's stages since the idea of staging is to keep only the stuff you need throughout the mission while getting rid of the rest as it becomes useless. Replacing the vanilla parachutes with stats of your own was a good move and I can't get why it has been undone. You obviously put loads of great and realistic new features into the new versions and this is probably more realistic but it seems to defeat the purpose of having several different types of parachutes and even a micro-burn to brake at the last second if there is a 50m parachute doing all the work for you and threatening to trap you under it you once it comes down. I'd envision the big ones to be the last solution for heavy crafts having to land on duna for example. Instead of one huge chute, you could easily fit in three small ones that would do the trick and look way cooler. About those, where are they? I can't get my hands on them and I suppose you need to change the whole part.cfg to avoid overlap, ... Even the ones that deploy two chutes overlap. That's a bit of a shame :/ The single chutes should be stored away in the stock parts that have a smaller profile (or a new part with the same profile). I'll try and play around with values until I get something I'm happy with but I'd be really greatful if you could give me the version you had after the major update to have the new features but before you changed the chute to 50m. If you don't have it anymore, could you tell me how to get those three parachutes that don't overlap? For now I'm using the drogue chutes for main chutes which is actually really fancy because it forces you to do a last-second burn to have a smooth landing

You have it all wrong.

The 50m parachute is not there to be OP. It's there because of a specific reason: it is the required diameter to make a 4.5 ton body land at 6m/s on the surface of Kerbin. and 4.5tons is, well the mass of the mk1-2 pod. If you have anything heavier, it won't do the same job. If you are on Duna, it won't do the same job. The kerbal environment does not change the physics. Drag stays drag, and you have to deal with it the same way. You don't need four time less drag than real life because it's in Kerbal universe. Also, for the "three small ones" I have already asked sumghai, and he sent me the model for this already, it will be added in the next version.

For the overlapping, it really isn't that simple. You can't get them to not overlap by changing something in the config, unless you put the parachutes outside the case. If it was that easy, I would've done it.

P.S. the Apollo capsule parachutes had an equivalent diameter of 45m and the Dragon has the equivalent of 65m of parachutes.

Play however you want, but know that it's not that easy, else I would've done it, yes thank you.

It seems this is a bug...

No, you need to change the value of "caseMass" because the case is now the whole pod. So caseMass should be paraclampotron + pod = 0.3 + 4.5 = 4.8

The new shapes looks ugly, they are too big.

Also the menu part count is increased by a lot.

Why always modders dont take care of this issue.

There is a limit to the amount of parts that we can add to the game. Also the loading time increase, the game performance decrease and find a part in the menu selection between many is harder.

All these addoms would be great if they come in form of procedural parts. Snapping between standard sizes.

I will keep the old version of real parachutes.

Not my problem if you don't like the parts, use the stock MM file. Also, I could add 100 new parts and not increase your load time, because these parts all use the same models.

And lastly, for the 1000th time, procedural parts are planned.

Guys, this is a little irritating, but please take some time to be well informed when submitting a report/complaint. It's not only annoying for me, but I'm extremely busy and I end up wasting a lot of time on this.

[scottholio]

Personally, I like the new parts' look. I was actually going to ask you Chris if you could add a couple more parachutes. I was hoping for some chutes that have drogue and main chutes in the one part with auto-cut of the drogues at x altitude etc.

Edit: Don't focus on the negative comments mate, I really enjoy this pack and appreciate all the work you have put into it. Thnaks for sharing it.

Edited December 10, 2013 by scottholio

[stupid_chris]

Personally, I like the new parts' look. I was actually going to ask you Chris if you could add a couple more parachutes. I was hoping for some chutes that have drogue and main chutes in the one part with auto-cut of the drogues at x altitude etc.

Next update I already have received them, I even used them here, I'm just waiting to add a few more things to my code, for a fix to a bug concerning the new triple chutes models, as well as for .23 before pushing the next update.

[scottholio]

Next update I already have received them, I even used them here, I'm just waiting to add a few more things to my code, for a fix to a bug concerning the new triple chutes models, as well as for .23 before pushing the next update.

Nice, looking good

[rosenkranz]

Personally, I like the new parts' look. I was actually going to ask you Chris if you could add a couple more parachutes. I was hoping for some chutes that have drogue and main chutes in the one part with auto-cut of the drogues at x altitude etc.

Edit: Don't focus on the negative comments mate, I really enjoy this pack and appreciate all the work you have put into it. Thnaks for sharing it.

This. Much better than just reusing the stock models.

I did have a question about the deployment. I accidentally deployed them early and they semi-deployed at that point but I don't think they were doing anything and they were going all kinds of crazy directions (not just backwards but all directions, this particular rover had 19 of them). It was quite amusing to watch this go on but i was worried they wouldn't deploy correctly.

Well they did finally (officially) semi-deploy at about 25000m and I watched the g-meter peg out come back to something normal. The orientations also came back to normal. I'll try to post pictures later (assuming i can get it to do that again)

[stupid_chris]

This. Much better than just reusing the stock models.

I did have a question about the deployment. I accidentally deployed them early and they semi-deployed at that point but I don't think they were doing anything and they were going all kinds of crazy directions (not just backwards but all directions, this particular rover had 19 of them). It was quite amusing to watch this go on but i was worried they wouldn't deploy correctly.

Well they did finally (officially) semi-deploy at about 25000m and I watched the g-meter peg out come back to something normal. The orientations also came back to normal. I'll try to post pictures later (assuming i can get it to do that again)

This is probably related to the bug someone mentioned eariler. The parachutes orientations are borked a little sometimes, I believe I fixed it, this should be packaged with 0.3.2

[Lazurkri]

stupid question, but does this work in career mode?

[stupid_chris]

stupid question, but does this work in career mode?

Sure does, if I'm not mistaken, all the parachutes are currently assigned to the same node as stock equivalents. After 1.0 I'll do a "career" update and I'll work this a little more.

[Aknar]

I don't wish to bug you with this but I feel I was misunderstood. It seems odd to me that in a universe that is scaled down, we have parachutes the size of the human ones. The cockpit is kerbal-sized so something around half the size of a human one. The old ones seemed more appropriate... The drogue chutes are of a similar size and can bring down a heavy craft even if you do need a burn at the last second, so going for something that massive seems a bit over the top for the task at hand.

For the triple parachute and overlapping. I though that it was done by defining their orientation like you would for flame effects for exemple. Of course, I understand that it only works for the part itself and not parachutes from other parts.

I understand you might not share my opinion and I don't want to appear ungrateful for this wonderful mod you made. I have an idea of how difficult most of this must be, and this is why I am not doing it myself. I'm stuck playing with values in the .cfg files. I am also aware of how much time you put aside to answer every single post and that really changes from other threads I'm used to posting on, and I want to thank you for that as well

Edited December 10, 2013 by Aknar

[stupid_chris]

I don't wish to bug you with this but I feel I was misunderstood. It seems odd to me that in a universe that is scaled down, we have parachutes the size of the human ones. The cockpit is kerbal-sized so something around half the size of a human one. The old ones seemed more appropriate... The drogue chutes are of a similar size and can bring down a heavy craft even if you do need a burn at the last second, so going for something that massive seems a bit over the top for the task at hand. I understand you don't share my opinion and I'm sorry to appear ungrateful for this wonderful mod you made.

It's totally normal to have parachutes earth sized on Kerbin. Let's go through it in steps.

Drag is a vector. It's orientation is the inverted orientation of your velocity vector. Until now this should be all good.

Now this is how the force applied by drag is defined:

Df = ½ * rho * v² * Cd * A

Where:

Df is the force in N

rho is the atmospheric density in m/kg³

v² is the speed in m/s squared

Cd is the drag coefficient, no units

A is the cross sectional area, in m²

Now, to calculate how large your parachute must be you must do this little physics trick. Here, you want the drag force to equal the gravitational force that is imposed on the object. Gravitational force is defined this way:

Fm = m * g

Where:

Fm is the gravitational force in N

m is the mass of the object in kg

g is the gravitational acceleration in m/s²

so this means Fm = Fd => m * g = ½ * rho * v² * Cd * A

Now we want to figure out the diameter we need. Let's isolate it area.

m * g = ½ * rho * v² * Cd * A => (2 * m * g) / (rho * v² * Cd) = A

Now that we have this, we need to know what the diameter is.

A = r² * pi => A = (D/2)² * pi => A = (D² * pi) / 4

Let's plug this in the equation we had before

(2 * m * g) / (rho * v² * Cd) = (D² * pi) / 4 => (8 * m * g) / (rho * v² * Cd * pi) = D² => sqrt((8 * m * g) / (rho * v² * Cd * pi)) = D

So we have it, the formula of how to calculate diameter!! Now let's compare the environment specific variables Earth to Kerbin!

Earth gravity: 9.81m/s²

Kerbin Gravity: 9.81m/s²

Earth atmospheric density ASL: 1.22 kg/m³

Kerbin atmospheric density ASL: 1.22kg/m³

The rest depends of the vessel. And since units are measured the same way here than on Kerbin, the equation is the same at both places!

Now let's see here. The mk1-2 pod weights 4500kg. We want to land it at 6m/s. Let's say we use a Nylon parachute of a Cd of 1.

m = 4500

g = 9.81

rho = 1.22

v² = 6 * 6 = 36

Cd = 1

sqrt((8 * 4500 * 9.81) / (1.22 * 36 * 1 * pi)) = D

Type this in your calculator, you'll get D = 50.59174415m

This is where the 50m of my parachutes come from. The Kerbin scale only changes the width of the planets and the orbital energy, it does not affect drag in any way. The gravitational pull is the same, the atmosphere is the same, the parachute is the same.

Sources:

http://my.execpc.com/~culp/rockets/descent.html

http://en.wikipedia.org/wiki/Drag_(physics)

[XanderTek]

Chris, I've noticed that the deployed parachutes are further from the craft than in stock. Is that just a function of bigger chutes getting longer lines? Totally cosmetic, just wondering if there's any way to change that. I find I have to zoom way out to even see the parachute.

Aknar, it should be a pretty simple config change to resize them as you like. Just make sure that [parachute deployed area]x[drag coefficient]= the same number as before you started.

[stupid_chris]

Chris, I've noticed that the deployed parachutes are further from the craft than in stock. Is that just a function of bigger chutes getting longer lines? Totally cosmetic, just wondering if there's any way to change that. I find I have to zoom way out to even see the parachute.

It's necessary, else the parachute canopy would look "flattened". And so work models.

[thorfinn]

I don't understand whether the "new main" chutes are two-stage drogue+main parachutes... if not, I recommend those

Since lots of things seem to be in flux I think I'll wait for 0.23 to rebuild my modpack and add this one also, but great job!

[DasBananenbrot]

Speaking of 0.23 I am thrilled of how the new tweakable system will work and I hope (not so) stupid_chris won't have problems make it compatible with RealChute

Edited December 10, 2013 by DasBananenbrot
Just realised I made several mistakes D'oh