Why do decoupler shrouds pay any attn to engine diameter?

[E. F. Kranz]

Let me say first, I don't even know how shrouds are created inside the game.

But because of the updates, I've given a shot at playing with the stock parts, while I wait for the mods I prefer to stabilize.

So now I've realized that even using stock parts, decoupler shrouds don't work right.

Currently, the shroud generator is attached to the diameter of the engine. But that's not the way it should be.

It should look at the tank diameters above and below the engine, and connect them. If there's a differential, the shroud should be tapered.

Because SQUAD seems to be so competent in the other design aspects of this game, I have to assume this is a fundamental limitation of the Unity game engine?

Can anyone elucidate the situation re: decoupler shrouds?

[rodion_herrera]

The diameter is based on the diameter of the ENGINE ABOVE THE DECOUPLER, and NOT the diameter of the decoupler itself or the diameter of the fuel tank on top of the engine. Thus, if you've been experiencing "thin" shroud, it's because that engine is smaller than the tank above it, even though your have a wider decoupler at the bottom. Again, based on ENGINE and not TANK.

So if you have an LV-T45 stuck to a large tank above it, don't expect that if you place a large decoupler on the bottom, that the shroud would be same diameter as large tank and large decoupler--the LV-T45 is small, so the shroud will be small--only if your engine is as large as Skipper or Mainsail, will you see the large shroud.

Edited June 3, 2013 by rodion_herrera

[stupid_chris]

It has always been like this, and since shrouds are not a physical form and have no collision mesh, they probably never took the time to change it. It doesn't change anything to the game, your rocket won't be less structurally stable because your shroud isn't sized to your engine.

[E. F. Kranz]

Yes, gentlemen, I realize that. I'm asking why.

It seems to my layman's mind a fairly simple thing to pay no attention to the engine diameter. There may be situations where one wishes to put a small rocket under a large tank.

The shroud generator should be able to look at the tanks above and below the engine, and construct the shroud accordingly. I'm trying to figure out why it doesn't.

[stupid_chris]

Yes, gentlemen, I realize that. I'm asking why.

It seems to my layman's mind a fairly simple thing to pay no attention to the engine diameter. There may be situations where one wishes to put a small rocket under a large tank.

The shroud generator should be able to look at the tanks above and below the engine, and construct the shroud accordingly. I'm trying to figure out why it doesn't.

I answered you, they just didn't bother to change it. Since it doesn't affect the gameplay in anyway, they probably just don't want to put the development time on this yet. That's all.

[Specialist290]

The simplest explanation is probably that the shroud is generated as part of the engine, not part of the decoupler.

[Temstar]

But if we generate the shroud according to the tank above, how would a Poodle should look like if it's attached to the bottom of a 1.25m stack?

[E. F. Kranz]

But if we generate the shroud according to the tank above, how would a Poodle should look like if it's attached to the bottom of a 1.25m stack?

There would be no shroud, because it would intersect with the engine.

Again, I'm no game designer (anymore), but this isn't exactly rocket science, it's simple math.

[stupid_chris]

This sounds like too much development time for a purely aesthetic thing in this game. I think they can leave that aside for now and work on more important things.

See here

[Temstar]

There would be no shroud, because it would intersect with the engine.

Again, I'm no game designer (anymore), but this isn't exactly rocket science, it's simple math.

But then we'll have other people complaining "Why do I get no shroud when I attach 2.5m engine under 1.25m stack? Fix plz Squad."

[rodion_herrera]

But then we'll have other people complaining "Why do I get no shroud when I attach 2.5m engine under 1.25m stack? Fix plz Squad."

Don't forget the other people saying/commenting, "Nooo, leave it as is--it's so...KERBAL!"

[E. F. Kranz]

This sounds like too much development time for a purely aesthetic thing in this game. I think they can leave that aside for now and work on more important things.

I can't argue that this should be a high priority, and you might note that my original post was inquisitive, rather than critical.

Perhaps this very issue is already on the development calendar, and I'm simply caught unawares?

[E. F. Kranz]

See here

A sincere thanks for the link.

[Brotoro]

I hope that the ability to add custom shrouds will be added eventually, and then you could cover any default shrouds that offend your sensibilities as well as making payload fairings and whatnot. But the default engine shrouds are better than nothing (back in 0.17 or whenever we didn't have them), and they work fine in most cases, so I'm not overly worried about getting this Right Away (I'd like to see some other basic things fixed first).

Edited June 3, 2013 by Brotoro

[Catullus]

You could just use the right size of decoupler and a size adapter underneath it.

[Supernovy]

The model for the fairing is actually inside of the model for the engine.

From the Skipper engine config:

MODULE

{

name = ModuleJettison

jettisonName = obj_fairing

bottomNodeName = bottom

isFairing = True

jettisonedObjectMass = 0.5

jettisonForce = 15

jettisonDirection = 0 0 1

}

Where obj_fairing refers to the mesh in the model.mu file.

EDIT: You didn't hear it from me, but DYJ is looking to make procedural fairings similar to his procedural wings.

[Finnerty]

It doesn't change anything to the game, your rocket won't be less structurally stable because your shroud isn't sized to your engine.

It changes my game because the shroud doesn't match the tank diameter and is less stable when using the nuclear rocket. Its much smaller in diameter and has to be strutted to make it stable enough to not come apart at this skinny section of rocket.

[NovaSilisko]

Shrouds aren't "Generated". They're part of the model. We're going to have shrouds that stretch to fit the diameter of the part below them but that's a very low priority thing as has been said, and will be worked on at some point in the future, when we're more in the polishing phase as opposed to the deeper development phase.

[stupid_chris]

It changes my game because the shroud doesn't match the tank diameter and is less stable when using the nuclear rocket. Its much smaller in diameter and has to be strutted to make it stable enough to not come apart at this skinny section of rocket.

The problem here is your engine that is too small for what is under. The shroud has nothing to do here. If there was no shroud at all, you would have to strut it too. The problem isn't the shroud here.

[E. F. Kranz]

The model for the fairing is actually inside of the model for the engine.

That is what I assumed. Appreciate the confirmation.

Shrouds aren't "Generated". They're part of the model. We're going to have shrouds that stretch to fit the diameter of the part below them but that's a very low priority thing as has been said, and will be worked on at some point in the future, when we're more in the polishing phase as opposed to the deeper development phase.

That prioritization makes sense. Being unfamiliar with Unity, perhaps I can't see why it'd be more than a few lines of code.

[the_bT]

It should look at the tank diameters above and below the engine, and connect them. If there's a differential, the shroud should be tapered.

The Unity engine has some capability to create meshes on the fly, however its not as easy as you make it sound. While your suggestion would work if the diameter under the engine is larger than the one above it, if it is the other way around you will get into trouble.

And even if you somehow get around that, you are not done just generating the geometric form of the shroud (which is only trivial if you refrain from adding any detail). You will need to generate a texture mapping too. And that can get ugly quickly. If you want the lighting to look right (you do!) you need to generate normals for your geometry. If you want to use a texture with a bump map you need to generate tangent vectors. That is all doable if you put some effort into it. But what is the reward? A shroud that looks better in some situations and worse in some other situations?

I agree that it does look weird. It really does. But there is no easy way around.

Thinking about it, It might work by animating the shroud model and then lock that animation in one frame depending on the diameters. But the texture mapping would still be problematic. It needs to look good in all situations, nothing looks worse than a distorted texture.

[erkha343]

The problem here is your engine that is too small for what is under. The shroud has nothing to do here. If there was no shroud at all, you would have to strut it too. The problem isn't the shroud here.

Yes, but in real life that is what hold the engine and the previous stage together.