[1.0.x] [V1.9f] Kerbal Foundries wheels, anti-grav repulsors and tracks

[Haifi]

At least the tracks should have better traction. The only problem is, when your movement is more like floating or levitating in low-G, its not a problem of traction anymore but of mass.

[lo-fi]

It's a bit of a balancing act with all of these things. Settings that work on one world are useless on another; the TR-2L's are a great example of this. They have enough grip to work in low gravity (though still arguably too much), but put them anywhere near a normal gravity world and they're useless and flip craft quicker than even Jeb can manage. Tracks tend to be a bit more stable due to the negative feedback the steering method gives. In reality, I think, tracks would be rather useless in low grav because of their inherent low ground pressure, where actually skinny bike wheels would be a much better option for traction... But it's a game with reckless little green aliens with the body conformation of a fig roll & an impossibly big skull, it's supposed to be fun and tracks look cool, so I've tried to hit something in the middle.

[Madrias]

You see, that's where I disagree. Sure, skinny little bike wheels may allow you more mass per square centimeter of your contact patch, but the tracks offer more surface area to move the vehicles.

Either way, we need both. Skinny wheels for those who want 'em, tracks in various forms, a good set of mid-size wheels (and the repulsor wheels fit the bill 100% as a perfect 'usable' size.), some small wheels for small rovers, giant wheels for mobile bases, and super-high-tech anti-gravity devices.

And yes, I also agree, a repulsor with the batteries put in backwards would be nice for ultra-low-gravity worlds, partnering with the tracks/wheels.

We also need some form of a repulsor turned into an engine (providing forward thrust) and a repulsor-based RCS, so we can have 100% electric powered vehicles. Of course, these things should have stupidly high power draw because they're using the repulsors to do things they aren't supposed to do.

[Haifi]

I dont like to be a naysayer, but repulsors that work horizontally as in providing thrust. I dont think i would like that and besides i dont think "science" on these would work that way. Theyre practically meddling with gravitation. As long as gravitation is a pretty monodirectional force towards a massive body's center I dont think you could bend it enough to give you horizontal momentum.

[lo-fi]

I guess ion engines are about as close as it gets to electric propulsion. Not really my field, and would need a far different mechanism than the repulsors which actually do work against gravity. I think the standard engine modules can be converted to run on electriccharge easily enough with some config bashing (though I could be wrong). If that's the case, it would be easy enough to produce something whether you deem it atmospheric only (fans) or otherwise.

I've been trying to find some scientific papers on grip vs ground pressure, but not a lot is easily forthcoming. I can't really see where low ground contact pressure gives any advantage to low gravity traction beyond what it does in normal gravity situations, though. It's sort of modelled with the use of multiple colliders, and last time I checked a tracked vehicle was able to climb some decent slopes. It's hard to gauge, and I'd hate to up it to stock flippy-crashy-boom-boom levels

[Madrias]

True, Lo-Fi, about making electric engines. (I've made a few oddball ones myself. You need ElectricCharge and some resource to keep KSP happy, but you can make a resource definition and some ultra-light resource, a small containment of that resource, and a generator for it all in that part. Mostly converted Ion-Engines for the model in my basic design.)

As for the tracks in game, I love the fact that the tracks have an ability to climb some wicked slopes at times. While I have difficulty on some worlds with the terrain (Eve is difficult because the two shades of purple are near-identical to me), I tend to enjoy slowly cruising around places like the Mun.

[Gaalidas]

Isn't electric charge technically a resource as far as KSP is concerned? I've run a few craft with EC as the only resource being used, but it tends to eat up a TON of EC no matter how you configure it. I only tried to take one of those engines (made to simulate a Star Trek style impulse engine running off a warp-core reactor as the only fuel source) and make it use only half of the EC and the result was an engine that provided miniscule thrust and required, literally, an infinite amount of EC to function. Since infinity does not actually exist, I had to scrap the idea. However, if you instead consumed EC into a generator that generated a miniscule amount of another resource with an extreme efficiency rating at the same rate the engine wanted to use it, you could simulate an engine using EC as its only resource without requiring the supposed infinite EC to run.

As for the repulsors being used as engines, i don't think that would work because they are actually reacting to the surface under them, along with all that gravity mumbo-jumbo (There is no gravity, according to one theory. The earth just sucks.) To repulse horizontally, you would need a wall behind you to push against. However, if one were to attach repulsors as an angle behind the craft, and pulsed the repulsion field between high and low settings rapidly, you might produce a sort of "wave" effect that could move a craft forward. If you also made inverse-repulsors that could pull you back towards the ground just enough to keep the craft at its current height but low enough to not counteract the repulsors from levitating the craft, then you could permanently set the angled repulsors to a higher setting and the constant fighting to repulse the craft to a higher level than the rest of the repulsors are set to would cause the craft to continually move horizontally to relieve the pressure. This could, theoretically, be used to keep a craft from sliding sideways while moving, and possibly even be used to slow/stop a craft. This could also have the effect of creating the ability to steer a repulsor-supported craft without slippage.

The theory behind this is actually possibly today with normal wheels and hydraulics, as far as the propulsion is concerned. If you have a vehicle which is restricted from moving vertically, and has an angled set of wheels in the back that are made to push downward, the vehicle will attempt to roll one way or the other to relieve the pressure (yes, I know it's more complicated than that, but this is very basic). If that restriction in vertical movement is at the back of the vehicle, and there is less restriction near the front, then the craft will attempt to roll that direction. Not very useful out in the world, but if we had repulsors in the real world, one could possibly generate a form of thrust simply by repulsing at an angle on the back, and pushing downward just behind the center of that repulsion reaction, thus creating something similar to when you squish the sides of a straw with water in it. The liquid moves to escape the collapsing space in the directly with the least resistance.

So, as far as I can make out, if the repulsor was not set up to only lift the craft vertically, but instead attempted to push the craft in the opposite direction of the repulsor plate (pointed down, craft moves up) then you might be able to create all of this without making individual parts for each purpose. I figure with regular wheels and a small engine on the back pointed upwards, you could get the same effect by raising the back suspension and throttling up. Of course, that would be very inefficient for a friction-based system like the wheel, and with repulsors you might be better off with some small engines on the back and some RCS stabilization systems pointing every other direction. Even if you didn't use repulsors for propulsion, it would be awesome to be able to use them for stability by angling them outward from the center of the craft, similar to how a roman archway supported the center stone the craft would settle into this "pocket" between the inward-pushing repulsors. You'd simply have to input more energy into the repulsors to maintain the same height as you would with vertically aligned repulsors.

Either way, inverted repulsors is something I've been toying with the idea of for a while now... ever since I discovered the squid-system mod a long time ago, before I even heard of this mod (in fact, before it existed.) EDIT: Squid was/is an Impossible Innovations mod (I think) which provided alternate versions of stock wheels which, when the squid was activated, would attach to the surface it was on and keep all wheels firmly attached while driving. I hated the visual effect associated with the activated squid system, but it certainly worked. It was built with landing on low/no gravity bodies and staying landed. This was before we had claws or even asteroids, but I believe the system would have worked on them too. END EDIT

EDIT: Huh. I think you hit a nerve or something. I wrote all that in about 60 seconds of frantic typing. Only took me 2 minutes to fix the glaring typos. I'm sure I missed a bunch of them.

Edited January 20, 2015 by Gaalidas

[datubaman]

It's a bit of a balancing act with all of these things. Settings that work on one world are useless on another; the TR-2L's are a great example of this. They have enough grip to work in low gravity (though still arguably too much), but put them anywhere near a normal gravity world and they're useless and flip craft quicker than even Jeb can manage. Tracks tend to be a bit more stable due to the negative feedback the steering method gives. In reality, I think, tracks would be rather useless in low grav because of their inherent low ground pressure, where actually skinny bike wheels would be a much better option for traction... But it's a game with reckless little green aliens with the body conformation of a fig roll & an impossibly big skull, it's supposed to be fun and tracks look cool, so I've tried to hit something in the middle.

Why not make it configurable? In fact, that's something I would like to see a bit more of with this mod. I love the tracks, but some of them are the right scale, but too short for what I want to do, while others are the right length for what I want, but are way to big scale-wise. I want to be able to configure the length and width of the track, as well as the height.

For the length, you could simply have a slider that you could use to adjust the number of road wheels as a means for adjusting length. Or you could do it the same way you adjust the length of the Missile Pylons in BDArmory. For the width and height, simple sliders would suffice. But yes, I think making the tracks tweakable would really be a vast improvement to this mod.

[lo-fi]

Wow, that's an essay even by your standards, Gaalidas! I'll need a big mug if coffee before tackling that one.

The vernor engine uses one resource, so I wonder if I things have changed now to make things easier without phantom resources... I'll have a quick look in the config.

I did look at procedural tracks briefly, but due to the nature of how the skinned mesh works to simulate movement with the suspension and the texture is rotated to give the idea that its actually rotating, its pretty much impossible. There's a small chance the width might be configurable, but that's about as far as it would ever go. And before anyone says "yeah, but can't you just...": you try rigging up even a standard track, then tell me how that's going to work out

The good news is we have tweakscale working, so that will open up lots of design possibilities for you with the next release, and there are more designs to choose from.

[Gaalidas]

It's crazy how my mind works sometimes. If only I could summon that kind of essay-writing power for those times when an essay is required.

[sebi.zzr]

Hello,lo-fi do you use "transformName" for AlphaRepulsor and what is the name?

[lo-fi]

Not really sure what you mean?

[sebi.zzr]

Not really sure what you mean?

I tried to add some visual effects to AlphaRepulsor with help from smokescreen,but i'm missing "transformName" like engines use.

transformName = thrustTransform
thrustVectorTransformName = thrustTransform

Usually this is set in unity.

[Koosmonaut]

I'm pretty sure the Repulsors are very heavily tweaked wheels, so I wouldn't be surprised if they didn't have any 'thrustvector'.

[lo-fi]

Ah, I see. Koosmonaut is right, they're not engines and have no thrust transform. I'll have a look in the model though, there may be a conveniently placed transform you can use to play around.

[Gaalidas]

Or you could probably add a dummy transform conveniently named "thrustTransform" for that. Hmm, this could be the ticket to adding a sort of "glow" emission like the ion engines have (or like the Near Future electric engines) and then a sort of "overload" effect to the repulsor, perhaps to be displayed when the repulsor is at maximum output. Hey, I just had a thought. How about a red "overheating" style glow for the repulsor plate when running at maximum and still having issues, reduced by adding more repulsors to the craft to support the weight? They could have an actual heat production like you'd get on engines, and could tie into the system other mods use for bleeding off excess heat. That could make the repulsor system a little less "cheaty" for the hardcore player.

Something to think about for the next beta after we release this one.

I would strongly suggest, sebi.zrr, that you wait a bit before doing any more serious work on that effect. We're getting ready to unload a massive update to this stuff. On the up-side, the repulsors haven't changed all that much so maybe you've got little to worry about. Just backup your work, cause there have been some name changes.

Edited January 20, 2015 by Gaalidas

[lo-fi]

Certainly lots of options and the repulsors definitely deserve some love having been a bit overlooked while I've been messing with tracks and wheels.

Effects tied to how hard they're working would be really cool.

Also, anyone got any ideas for texture to put in the marked places on the rover body?

Hint: This is the last thing on my list before hitting the RELEASE button.

EDIT: sebi.zzr , you will be able to use a transform called Grid, but I believe this was changed since 1.7, so do hang fire for the moment, I think it's changed since 1.7. It may have been called Mesh001 previously, but I can't confirm without spending a lot of time digging around.

Edited January 20, 2015 by lo-fi

[Madrias]

Plain gray (or whatever the current texture color is) with some rivet detailing, perhaps?

[riocrokite]

http://www.cgtextures.com/ might help

[lo-fi]

Thanks guys, I run out of inspiration sometimes

[riocrokite]

Thanks guys, I run out of inspiration sometimes

hmmm, since you ran out of inspiration - I need some wheels...

check out http://www.etftrucks.eu

[Madrias]

I could use that whole truck with a flat bed instead of a box. Got a few really good ideas in mind for something like that. And by the looks of it, there's a decent driver's cab up there, too. Add to that an onboard APU and fuel supply, and it'd be awesome.

[riocrokite]

I could use that whole truck with a flat bed instead of a box. Got a few really good ideas in mind for something like that. And by the looks of it, there's a decent driver's cab up there, too. Add to that an onboard APU and fuel supply, and it'd be awesome.

I hear ya:) I need top-mounted heavy wheels that can turn widely (important for long vehicles) and then have all suspension and stuff hidden inbetween them, not on the right/left side so the whole construction is narrow and fits underneath the sides of a frame If you can do it I promise I can collaborate and prepare special version of frame so it all fits nicely;)

But yah, only 8.61% of people want more wheels so maybe after your next release?

Edited January 20, 2015 by riocrokite

[lo-fi]

If you'd like to model and texture something I can certainly rig it up and configure for you, it doesn't take me long Only caveat is that the model needs to be symmetrical left to right for that kind of mounting, but that shouldn't be too much of a hardship with that design. The KF plugin does the steering like that as standard, so it'll be a good choice.

[Mekan1k]

Please PLEASE update the download soon! (I want to play with the tracks again...)