[0.17] Re-entry Heat Module and Mk-1 Pod Heat Shields

[Subcidal]

Oh god it's amazing.

Make some various sized heatshields. the .75 or .5 size (Like the size of the mk16 parachute) would be nice for certain probes and stuff. And add the ability to decouple and this mod is going to be one of the best ever.

Edit : So I just came in at a steep angle to blow one up for you know... test reasons....

Anyway, I can't end the flight, It did blow up though, The game isn't frozen i can still mouse around it's just fixed onto the area that I blew up at.

Edited September 25, 2012 by Subcidal

[Tommygun]

Been using the latest version and it is a lot of fun.

I have a question, I deployed two separate parachutes when my speed was at about 1000 m/s and it destroyed only one of the chutes.

Does your plug-in recognize more than one chute for destruction?

Also have you considered modeling the damage to a parachute?

If the chute opened at say 380 m/s, the chute uses a damaged texture in place of the normal one and the drag is only 80% of normal.

[DasPenguin85]

Well, this time around it worked flawlessly, even with Mechjeb.

I would hate to give any critique, considering that it just got to a working version - which is awesome, by the way. However, I find it messing with my perception that the smoke and flames seem to move so slow, mostly the smoke though, that seems like the effect is tied to the craft, but not the world/simulation, so it appears very slow. I guess a better way of putting it is that I don't feel like my craft is ripping through the atmosphere at 2,000 m/s, it feels more like a slow floating effect, like 20 m/s.

I'd be remiss if I gave critique with no help though, so I feel obliged to extend an offer of my skills: if you need more models, textures, or animations, shoot me a PM - I have 15 years experience with 3D Studio Max under my belt, I can send sample images of my work.

Cheers dude!

PS> Thank you for this mod! All critique aside, I've been waiting for something like this for ages, and every time I re-enter Kerbin's atmosphere I get that feeling like I'm watching the ending of Apollo 13, but alas KSP has no vanilla effect for reentry, and you've brought me one step closer to that level of immersion.

[Moach]

just a note - i've managed to provide inherent stability using a torque instead of hijacking the flight controls -- it's still quite unsteady (might be my top-heavy pod design, tho) but it already shows it's possible keep the shield pointed the right way without overriding input....

tests are still being tested

got the new version too - i'll put the changes together with mine before i send it over

cheers!

[PakledHostage]

I am happy to hear that my bug fixes have improved things! I was aiming to deal with the "show stoppers" so that people newly downloading the mod would have a more positive first impression. This will buy time to work on polish and solving some of the remaining nuisance items...

@Moach: Sounds like a good idea. I look forward to seeing what you come up with.

@DasPenuin85: The module is structured so that it can be used with any heat shield part that has a built-in heat animation. Just develop your 3D model and include an emissive animation. There are tutorials on this forum for how to do KSP compatible models and animations in Unity3D. Configure your animation model so that it "plays" from coldest to hottest. I just display the animation frame by frame, depending on the temperature that I calculate for the heat shield. Use my module’s "HeatShieldHeatAnimation" parameter in the part.cfg file to set the name of your heat animation.

Also, MrPwner is working on a transparent texture for emissive animations. It is an impressive bit of work because, as far as I know, it has never been done before with any other mods in KSP. When he gets it working, he will add a transparent detached shock effect to the plugin.

@Tommygun: I like your suggestion but I think the way to deal with parachute damage is in the parachute module itself. Parachute parts could have a parameter in the part.cfg file that sets the rated opening speed. Open it above that speed and it takes damage. If this were handled in the parachute module, then I wouldn't have to apply my cludge to destroy parachutes that open in the middle of the plasma trail...

@Subsidal: I will add this to the list of bugs. I suspect that there's an additional function that I need to call to end the mission when I destroy the spacecraft.

Edited September 25, 2012 by PakledHostage

[Pleborian]

and this is why the ksp modding community is pretty awesome, look at you guys are working together to make new awesome things excellent work on the mod btw, not exactly practicle with my current playing style but I tried it out and was like 'well.... that was pretty good' even though I lost bill jeb and bob

[Sbowyer28]

I wish there was A way I could help but i cant model or code, IM GOOD FOR NOTHING:)

[Moach]

if you can fly, you can help! - everybody needs test pilots, most certainly kerbals!

coders do enjoy getting the maximum possible information on how things are working - specialy so when they're not, so it always helps to have a set of brave test pilots running every possible configuration and pushing the envelope so we can find the proper balance between the omg-many things that can make or break stuff like this

and you'd be surprised how easy coding comes along when you have a stimulating purpose for it in mind

[Sbowyer28]

I cant help test because my computer lags to where some plugin's dont work. A little off topic but have you ever thought og making a G42-200 Starliner for KSP moach?

[Moach]

it has occurred to me.... but then, it'd be kinda tough to make it in any way where the parts aren't extremely specialized and restricted to that one configuration.... plus, without a proper atmospheric model, it just doesn't work (drag should ease off passing the sound barrier, KSP just keeps building it up until something breaks)

speaking of which... some "light" reading down at wikipedia on the matter at hand here revealed quite a convenient mathematical coincidence

turns out, the peak shock temperature a vehicle can expect during reentry is pretty much the same value (in Kelvin) as the velocity in m/s -- that could cut quite a corner in simulating this stuff for KSP (where scientific precision can be stretched a little to make ends meet)

An approximate rule-of-thumb used by heat shield designers for estimating peak shock layer temperature is to assume the air temperature in kelvins to be equal to the entry speed in meters per second  a mathematical coincidence. For example, a spacecraft entering the atmosphere at 7.8 km/s would experience a peak shock layer temperature of 7800 K. This is unexpected, since the kinetic energy increases with the square of the velocity, and can only occur because the specific heat of the gas increases greatly with temperature (unlike the nearly constant specific heat assumed for solids under ordinary conditions).

curious, huh?

[Sbowyer28]

I may be able to test too now that I think about it and I have a suggestion, an aeroshell or Higher Velocity entry's (Such as Duna or eve) that can hold a small 1 meter or 0.5 Probodyne or MMI probe.

[PakledHostage]

speaking of which... some "light" reading down at wikipedia on the matter at hand here revealed quite a convenient mathematical coincidence

turns out, the peak shock temperature a vehicle can expect during reentry is pretty much the same value (in Kelvin) as the velocity in m/s

I noticed that when I was developing the re-entry heat physics model. It is one of the facts that I used to check my work. It gave me some comfort that the values calculated by the current re-entry heat physics model that is used in the module already agree quite well with this. You can set the "DisplayHeatShieldUI" parameter to "True" in the heat shield's part.cfg file if you want to view the shock temperature all throughout the re-entry. Also, you may want to have a look at the the Re-entry Heating Model thread, over in the General Discussion section. This explains the current re-entry heat physics model in detail.

I guess the question then becomes, do we use a physics model that has at least some physical significance and basis in aerodynamics & thermodynamics, or do we just fudge it? I prefer to stay with the physics model currently used in the module because it isn't just based on a rough rule-of-thumb. This allows re-entry effects to be varied somewhat realistically for different planets, merely by changing one or two constants in the model. The model will then respond according to the properties of the atmosphere that exists on that planet. That is the way it works right now, with the exception that gamma and the simplified heat transfer coefficient are the same for every planet/moon with an atmosphere.

And as for making this module work with other heat shield/aeroshell parts, maybe the best way to do that would be to expose the HEAT_DAMAGE_LIMITS constant as a parameter that can be set in the part.cfg file. Heat shields and aeroshells that are designed for higher speed re-entries could have higher heat damage tolerance, maybe with a corresponding weight penalty to maintain some play balance and challenge.

Edited September 25, 2012 by PakledHostage

[ddavis425]

I did a short suborbital flight to see the effects, but all I got was 2 puffs of smoke. I thought that I needed more speed, so I tried reentry from a Mun return trajectory. The heatshield got very bright, but I didn't see any flames

[PakledHostage]

I did a short suborbital flight to see the effects, but all I got was 2 puffs of smoke. I thought that I needed more speed, so I tried reentry from a Mun return trajectory. The heatshield got very bright, but I didn't see any flames

Hmmm...

What warp were you using?

What did you set your periapsis altitude at?

What if you try, say, starting from a LKO in the 80km to 100 km range and lower your periapsis to somewhere in the 25-35 km range? It shouldn't make a difference if you enter in real time, but what if you re-enter at 1x time warp? Does that make a difference? You should see a plasma trail comparable to that of the video on the first page of this thread if you re-enter this way. If you still don't see any re-entry effects, then there must be some game setting or video card issue that is preventing the smoke effects from being displayed?...

[ddavis425]

I had decoupled the pod and activated the heatshield in orbit around the Mun, Kerbin periapsis was ~10km. I used time warp to get from the Mun to Kerbin's atmosphere (not sure what warp setting, but I did use physical warp at one point). I just tried another flight, AP was 100km and PE was 20km, the heatshield glowed but never gave an effect. I'll try another flight without using time warp.

Edit: I did several more flights, at varying speeds and angles, with and without time warp, and I still can't get any effects to show up other than the glowing heat shield.

It still looks nice.

Edited September 26, 2012 by ddavis425

[PakledHostage]

Edit: I did several more flights, at varying speeds and angles, with and without time warp, and I still can't get any effects to show up other than the glowing heat shield.

Thanks for trying!

The flame effect is just an instance of the game's built-in particle emitter. I am surprised that it isn't visible for you. Could it be something about your installation, video card or maybe even operating system?

[Sbowyer28]

Can I help test new Heat Shield's please.

[Olsson]

When decoupling sometimes during using a heat shield the decoupled part might blow up and say "Excessive g-loads/forces bla bla bla..". For example I have a 2m heat shield and then I have aeroshells which I decouple before I cut my craft loose from the heatshield the aeroshells will often explode at around 10 000m altitude which is when I do this.

[PakledHostage]

@Olsson: Can you post an image of your spacecraft? Or maybe even the .craft file? It sounds like you're using the re-entry plugin in another heat shield model. The logic currently expects the shield to stay attached to the command pod. I might need to change that if more people are installing it on parts that drop away (I can think of how to do it, but I'd need to try it).

@Sbowyer28: I did a bit more work on the module last night (I exposed an "AllowableHeatDamage" parameter so that it can be set in the part.cfg file), but there's nothing to test yet. I am waiting to see Moach's changes before I release another version.

Edited September 26, 2012 by PakledHostage

[Sbowyer28]

Thanx Also I can try to talk to Pelf if you want to turn his aeroshell into a working heatshield for this pack.

[PakledHostage]

I can try to talk to Pelf if you want to turn his aeroshell into a working heatshield for this pack.

That would be great! But he can actually already do it if he wants... All he'd have to do is create an emissive animation for his aeroshell model. He can set it up so that the animation "plays" from cold to hot. He then just needs to set the "HeatShieldHeatAnimation" parameter in the aeroshell's part.cfg file to the name of his animation. The current value "Heat" is the name of the animation in Dani-Sang's heat shield part that is supplied with my module.

My module looks for an emissive animation with the name specified in the "HeatShieldHeatAnimation" parameter. It then figures out how long it is and scales that length to the temperature range. It then just displays the animation, frame by frame, depending on the temperature.

[Sbowyer28]

Hostage have you ever thought of adding an Animation in the Stock Capsules for a "Burnt Effect" Like the Apollo or SpaceX Dragon Burn Marks on the side.

[PakledHostage]

have you ever thought of adding an Animation in the Stock Capsules for a "Burnt Effect" Like the Apollo or SpaceX Dragon Burn Marks on the side.

Unfortunately, 3D modelling is outside my area of expertise... It is its own specialty. I just make the programs that "make things go"... The 3D models have to be drawn and textured by people far more artistic than I am. They then compile their models into a format that can be used by KSP. The emissive animations that I mentioned above are compiled into the model at the same time.

[Pleborian]

actually been having alot of fun with this mod, trying to get a perfect burn effect while in IVA.

noticed a few of things though, the smaller heat shield works much better than the larger one. what I mean by this is that I can make it glow and burn, just glow or not do anything at all depending on my re-entry angle. now compared to the bigger heat shield no matter what it seems random what angles will make it glow, and as of the 10 attempts I have had I have never achieved a burn off it which leads me to believe its broken some how? another reason I think this is when you activate the shield itself one the smaller one a small window pops up with shock and shield temperatures, but the bigger one does not have this.

also this may be something that works correctly as I have no idea of the maths you guys have used to build this, but coming in on a very steep angle will negate the effects of re-entry but coming in very shallow will prolong the effects on your craft longer so you can experience the coolness of it all a little longer, not to long though of boom goes the craft shouldnt coming in steep just destroy your craft in mere seconds?

apart from that im going to continue enjoying the burn up effects a bit longer, not sure if any of the gibberish I just wrote will help but I hope so. Keep up the good work

[PakledHostage]

noticed a few of things though, the smaller heat shield works much better than the larger one. what I mean by this is that I can make it glow and burn, just glow or not do anything at all depending on my re-entry angle.

I want to tweak the logic for when it displays the plasma trail, but I haven't finished it yet. It is a compromise between what "looks cool" and "physical accuracy".

The reason the little UI window displays when you use the small shield and not the big one is that the "DisplayHeatShieldUI = True" option is turned on in the MK1-1 pod shield's part.cfg file. This was unintentional. Both heat shields are otherwise identical. The only difference between them is the part.cfg file (the larger one's rescale factor is set to 2.0, rather than 1.0). They both run the same plugin module.

also this may be something that works correctly as I have no idea of the maths you guys have used to build this, but coming in on a very steep angle will negate the effects of re-entry but coming in very shallow will prolong the effects on your craft longer so you can experience the coolness of it all a little longer, not to long though of boom goes the craft shouldn’t coming in steep just destroy your craft in mere seconds?

Not necessarily. Think of it like fried ice cream or waving your hand through a flame. You can expose objects to very high heat for short periods without appreciable heating. When you do a very steep re-entry, the spacecraft slows down so fast due to atmospheric drag that it doesn't have time to heat up. In that case, the spacecraft is destroyed by g-forces, rather than heating. I regard this effect as another piece of evidence that the re-entry heating physics model is actually working the way it should.

Edited September 26, 2012 by PakledHostage