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HotRockets! Particle FX Replacement + Tutorial


Nazari1382

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I can make something wide like that for the poodle specifically, but making it switch based on pressure is something a coder would need to help with.

That's on my list from when Nothke recruited me, yeah :)

It actually meshes really well with what RF is already doing.

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A lot of people are making incorrect statements about exhaust plume shape and size. Color just depends on temperature, and fuel mixture.

The exhaust plume size and shape is never the same as an engine travels through the atmosphere. When the exhaust plume is narrower than the bell nozzle, the nozzle is known as overexpanded. This is because the engine is operating outside of its optimal design conditions and it is too low in the atmosphere, so low that the air pressure is pushing in on the plume and the nozzle isn't getting every bit of force it can from the exhaust. When the bell nozzle is at the perfect balance of exhaust pressure and air pressure, the exhaust plume is exactly the same size as the nozzle exit and the engine has maximum efficiency. When the exhaust plume expands out past the bell nozzle, that means that nozzle is underexpanded and isn't capturing all of the pressure that the exhaust could provide (often the case in space). This is the whole reason why there are different Isp ratings for atmosphere and space for every given engine (just two in the case for KSP). So much depends on the size and shape of the bell nozzle. Keep in mind that some types of engines and some fuels work better in different environments as well, that is a different discussion

This leads me to an interesting thought. Nothke, if you want to get the simplest variable to use in changing the exhaust plume size, just use instantaneous engine Isp and compare that linearly to the min/max of the engine for simplicity. The problem with trying to do a variable exhaust plume is that each engine has a different sets of Isp's with only 2 data points (atmo and space). Realistically we should have a curve that shows Isp vs altitude. You could take the ground/space Isp and convert them to min/max at ground or space.

This means if Isp Ground is higher than Isp Space, the rocket should be optimal expansion at launch, then gradually become under-expanded in space (huge exhaust plume). Similarly, if the Isp Space is higher than Isp Ground, the rocket should be under-expanded (tiny exhaust plume) at launch and gradually become optimally expanded as it reaches space. I assume you need to use a plugin that makes the smoke and particle trails from the engine change with multiple variables (more than just thrust) in order to implement this, but I think it is perfectly doable with a few equations. Maybe have different algorithms for different types of engines (like nuclear vs standard).

Edited by Blaylock1988
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A lot of people are making incorrect statements about exhaust plume shape and size. Color just depends on temperature, and fuel mixture.

The exhaust plume size and shape is never the same as an engine travels through the atmosphere. When the exhaust plume is narrower than the bell nozzle, the nozzle is known as overexpanded. This is because the engine is operating outside of its optimal design conditions and it is too low in the atmosphere, so low that the air pressure is pushing in on the plume and the nozzle isn't getting every bit of force it can from the exhaust. When the bell nozzle is at the perfect balance of exhaust pressure and air pressure, the exhaust plume is exactly the same size as the nozzle exit and the engine has maximum efficiency. When the exhaust plume expands out past the bell nozzle, that means that nozzle is underexpanded and isn't capturing all of the pressure that the exhaust could provide (often the case in space). This is the whole reason why there are different Isp ratings for atmosphere and space for every given engine (just two in the case for KSP). So much depends on the size and shape of the bell nozzle. Keep in mind that some types of engines and some fuels work better in different environments as well, that is a different discussion

This leads me to an interesting thought. Nothke, if you want to get the simplest variable to use in changing the exhaust plume size, just use instantaneous engine Isp and compare that linearly to the min/max of the engine for simplicity. The problem with trying to do a variable exhaust plume is that each engine has a different sets of Isp's with only 2 data points (atmo and space). Realistically we should have a curve that shows Isp vs altitude. You could take the ground/space Isp and convert them to min/max at ground or space.

This means if Isp Ground is higher than Isp Space, the rocket should be optimal expansion at launch, then gradually become under-expanded in space (huge exhaust plume). Similarly, if the Isp Space is higher than Isp Ground, the rocket should be under-expanded (tiny exhaust plume) at launch and gradually become optimally expanded as it reaches space. I assume you need to use a plugin that makes the smoke and particle trails from the engine change with multiple variables (more than just thrust) in order to implement this, but I think it is perfectly doable with a few equations. Maybe have different algorithms for different types of engines (like nuclear vs standard).

It's quite hard to make an engine that has more efficiency in 1 atmo than in space. Why? Isp is not only about bell shape, but also pressure difference between the combustion chamber and the atmosphere. Oh, and KSP doesn't just use vacuum and 1 atmo Isp, it calculates Isp at different pressures from those two variables. If you right-click an engine, you can see the Isp go up while you're ascending.

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seems your mod makes my engines overheat. even a skipper on 70% thrust with 2 small tanks and a big one attached overheats and explodes.

i have quite a lot mods installed, so maybe there is an incompatibility somewhere? i'll try to find out witch mod it could conflict with, but given the number, this could take some time..

FAR, Deadly Reentry, Interstellar (maybe one of those 3), KAS, Kethane, KWRocketry, B9, Remotetec and a dozen smaller ones...

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seems your mod makes my engines overheat. even a skipper on 70% thrust with 2 small tanks and a big one attached overheats and explodes.

i have quite a lot mods installed, so maybe there is an incompatibility somewhere? i'll try to find out witch mod it could conflict with, but given the number, this could take some time..

FAR, Deadly Reentry, Interstellar (maybe one of those 3), KAS, Kethane, KWRocketry, B9, Remotetec and a dozen smaller ones...

It is deadly reentry...... If you would bother with reading just three pages back, you would have seen the post by NathanKell himself, where he explains the incompatibility and how to make a quick workaround...

Edited by DasBananenbrot
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It's quite hard to make an engine that has more efficiency in 1 atmo than in space.

Correct me if I am wrong, I thought in KSP there were a couple engines that had higher Isp in atmosphere than in space. I agree it isn't very realistic if this is true.

Why? Isp is not only about bell shape, but also pressure difference between the combustion chamber and the atmosphere.

Scientists design engines for specific applications. They know what atmospheric pressure (or range) their engine will be operating in and design a fitting bell nozzle because they also design the combustion chamber pressure. What I was explaining is why a single given rocket has doesnt have a constant Isp at changing altitudes.

Oh, and KSP doesn't just use vacuum and 1 atmo Isp, it calculates Isp at different pressures from those two variables.If you right-click an engine, you can see the Isp go up while you're ascending.

KSP doesn't calculate pressure differences, it just interpolates between ground Isp and vacuum Isp depending on what elevation you are in the atmosphere (if there is one present) to get the instantaneous Isp (the one you can click on and see). That is exactly what I was suggesting Nothke (or someone) use. That along with knowing the min and max and where the min and max are can be the parameters necessary to change the exhaust plume effects.

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The reason this breaks with DRE is because the modulemanager patch in DRE expects ModuleEngines, not ModuleEnginesFX. To fix this for now, for each engine that this modifies, find its entry in DeadlyReentry.cfg and

1. change @PART[whatever] to @PART[whatever]:Final

2. Right below, change @MODULE[ModuleEngines] to @MODULE[ModuleEnginesFX]

Just wanted to say that this worked for me. Thanks!

Edit: Now if we could just get shock diamonds in our exhaust... :)

Edited by Orum
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I would like to add sound to ion engine,where do i put my sound to be recognized?

@PART[ionEngine] //PB-ION

{

!MODULE[ModuleEngines]{}

EFFECTS

{

powerflame

{

MODEL_MULTI_PARTICLE

{

name = flameion1

modelName = MP_Nazari/FX/flameion

transformName = thrustTransform

emission = 0.0 0.0

emission = 0.10 0.00

emission = 0.15 0.45

emission = 1.0 0.75

speed = 0.0 0.75

speed = 1.0 0.97

}

AUDIO

{

channel = Ship

clip = sound_ion

volume = 0.0 0.0

volume = 1.0 1.0

pitch = 0.0 0.2

pitch = 1.0 1.0

loop = true

}

}

}

MODULE

{

name = ModuleEnginesFX

//engineID = rocketengine

//runningEffectName = powersmoke

directThrottleEffectName = powerflame

thrustVectorTransformName = thrustTransform

exhaustDamage = False

ignitionThreshold = 0.1

minThrust = 0

maxThrust = 2

heatProduction = 0

PROPELLANT

{

name = ElectricCharge

ratio = 12.0

}

PROPELLANT

{

name = XenonGas

ratio = 0.1

}

atmosphereCurve

{

key = 0 4200

}

}

}

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So i had time to test and it is awesome!!!!!!! Is there anyway i can add my own rocket flame effects? Or do i just recolor the files in the folder i want a green Nerva flame well because its radioactive

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a green Nerva flame well because its radioactive

The exhaust of the nerva is not (very) radioactive. It is hydrogen that has been heated by a nuclear reactor. There are no fissile materials in it (unless there is a problem with the cladding)

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