Launch pad/Runway quirks

[jros83]

For reasons unknown to me, it is clear that a rocket that starts with the default orientation, that is, East over the water is on the right, is vastly more stable even sitting still on the pad than one that is, for example, oriented in the VAB to "face" East (something I like to do for standard orbiting, and whether that's right or wrong is not the point of this). I don't see why this is the case. It would be nice in my opinion if a static rocket on the launch pad, all things being equal, starts equally as stable no matter how you have it oriented.

As well, for both the launch pad and the runway, why do vehicles always start slightly off the surface and drop in to place? That causes more stability issues with the launch pad than the runway, as on the runway you can always immediatly engage brakes. However, the fact remains that it's bizarre. Is there a behind the scenes reason why we are at 1.05 and vehicles can't start flush on the surface? If not, then I would also suggest that they do.

Maybe these things have been explained in the past, but I have missed those explanations.

I don't mean to sound upset or disgruntled. I am by no means either of those things. And I am enjoying KSP here at 1.05 as much as I ever have.

[Harry Rhodan]

4 hours ago, jros83 said:

For reasons unknown to me, it is clear that a rocket that starts with the default orientation, that is, East over the water is on the right, is vastly more stable even sitting still on the pad than one that is, for example, oriented in the VAB to "face" East (something I like to do for standard orbiting, and whether that's right or wrong is not the point of this). I don't see why this is the case.

Maybe because the pad, like the runway, is part of the absolutely flat KSC. It is slightly off the center of gravity and thereby slightly tilted to the west.

[jros83]

5 hours ago, Harry Rhodan said:

Maybe because the pad, like the runway, is part of the absolutely flat KSC. It is slightly off the center of gravity and thereby slightly tilted to the west.

Then I refer back to my issue of why do craft spawn in to the pad and runway just off the ground and drop in to place? If they spawned in flush against the surface, it would help mitigate the quirkiness.

 

Though, I get that due to game design and reduced dimensions, there is no "flat" surface on Kerbin, so I get nothing could start perfectly flush. But there has to be a better solution than spawning in a meter or two above the ground and falling in to place.

Edited December 3, 2015 by jros83

[Thorbard]

4 hours ago, Harry Rhodan said:

Maybe because the pad, like the runway, is part of the absolutely flat KSC. It is slightly off the center of gravity and thereby slightly tilted to the west.

Didn't realise that. Is that also why aircraft start rolling down the the runway of their own accord?

[jros83]

And again what's with craft spawning just off the ground and dropping in to place? That small drop can and usually does have an appreciable negative affect. On runway vehicles not so much, but on the pad it definitely does. The sole answer can not be to use those.... ugh what are they called (I don't have the game open)? The red stabilizers... That can't be the only answer. 1. in Career you don't start with them and 2. that's just a band-aid. In real life rockets don't start 2 meters off the ground, drop in to place and start to sway because of the drop. To be honest I am surprised there isn't more talk about this in the community.

Edited December 3, 2015 by jros83

[Dafni]

Does it still do this drop when you place your rocket/plane on the ground in the VAB/SPH before you click launch?

[jros83]

39 minutes ago, Dafni said:

Does it still do this drop when you place your rocket/plane on the ground in the VAB/SPH before you click launch?

Sometimes, and even when it doesn't, it still sways and acts a little goofy. Because it WANTS to drop in to place I can only assume.

[Padishar]

2 hours ago, Thorbard said:

Didn't realise that. Is that also why aircraft start rolling down the the runway of their own accord?

Basically, yes.  The whole of the KSC model is on a flat plane and is tangent to the sphere somewhere among the buildings (I believe the VAB is probably the center).  This also causes the runway to effectively slope to the right all along its length.

[jros83]

And is there nothing Squad can do about this?

[Torgo]

I see the 'dropping' thing more pronounced with the L1 and L2 launch pads. I don't see it as much with the L3 pad. Could it be a function of the L3 pad being higher? I'm not at home to look right now, but I recall seeing the ships dropping from the height of the L3 pad surface. 

[jros83]

5 hours ago, Torgo said:

I see the 'dropping' thing more pronounced with the L1 and L2 launch pads. I don't see it as much with the L3 pad. Could it be a function of the L3 pad being higher? I'm not at home to look right now, but I recall seeing the ships dropping from the height of the L3 pad surface. 

Interesting. If true, then one could assume all launch pad vehicles are coded to conform to one version (L3) of the launch pad, regardless of what state the pad is in in your game?

I could see that as being a cheap shortcut. Sorry Squad. No offense.

[wrcsubers]

10 hours ago, Padishar said:

Basically, yes.  The whole of the KSC model is on a flat plane and is tangent to the sphere somewhere among the buildings (I believe the VAB is probably the center).  This also causes the runway to effectively slope to the right all along its length.

Consider this extremely crude and highly exagerated Microsoft Paint rendition...

The circle is Kerbin, The flat horizontal line is the Launch Pad(or runway).  The line coming out from the middle of Kerbin is a tangent line.  The arrow is your rocket(or plane).  While in the game these dimensions are much larger making the angle much smaller the idea is still the same.  Your craft is going to point slightly West when sitting on the Launch Pad.

Another Example is if you take a plane from one end of the runway to the other, you'll notice that the altitude is lower in the middle than at the ends by about 1.5m; this happens for the same reason as above.

As for your craft 'dropping' I'm guessing that it has something to do with the physics being suspended while you are building your craft in the VAB/SPH.  The physics engine does a whole bunch all at once when your craft loads.  The Launch Stabilizer Clamps really do help a lot, but if you have a really heavy craft or funky design, it still might not do the trick.

Edited December 4, 2015 by wrcsubers

[Claw]

Yep, the above is true. Also, craft spawn above the surface because the potential for the alternative (spawning slightly in the ground) would result in catastrophe. 

[jros83]

16 hours ago, Claw said:

Yep, the above is true. Also, craft spawn above the surface because the potential for the alternative (spawning slightly in the ground) would result in catastrophe. 

There's another alternative.

Spawning flush.

[Claw]

That's true, but comes with an inherent assumption that spawning flush also comes with zero error. I'd love to say this is such a simple black and white fix. Spawning too low is also a problem. Take a look at the small fixed landing gear. That's an example of something that exists in the current system, but spawns too low already.

What actually helps out way more is if you have an example craft that spawns far too high, or experiences some similar issue. Then that helps us pinpoint specific issues.

[Stone Blue]

On 12/3/2015, 11:51:33, Padishar said:

Basically, yes.  The whole of the KSC model is on a flat plane and is tangent to the sphere somewhere among the buildings (I believe the VAB is probably the center).  This also causes the runway to effectively slope to the right all along its length.

I knew about the east-west slpe in the runway, but always wondered why everything seemed to veer to the right when taking off...

[Stone Blue]

20 hours ago, Claw said:

Yep, the above is true. Also, craft spawn above the surface because the potential for the alternative (spawning slightly in the ground) would result in catastrophe. 

I can attest to this... Using HyperEdit, you can easily test this...I found that HyperEditing a craft at less than 3m above the runway, causes the craft to spawn below the surface...Once the physics kicks in, the game sees this as a crash/collision with the ground...

[Stone Blue]

4 hours ago, jros83 said:

There's another alternative.

Spawning flush.

Whats flush, though?.... Many times EVA'ing Kerbals on the surface, I've had them clip into the ground... Happens a lot at the bottom of the slope at the east end of the runway... Also I've had them and craft clip while entering the water at the beach...

Also, the launch pad only seems to be more of an issue due to the design of most craft you launch from there vs from the runway (ie being long thin and VERTICAL, vs being wider and HORIZONTAL on the runway...

Also, I'm not sure whether part count or total mass affects how much wobbling happens at launch, but it seems higher count, higher mass ships get affected more...

Also, I think it actually seems better in 1.0.5...

[Claw]

I had to wait till I was at my KSP machine, but here's an example of some of the quirks I'm talking about (which also falls in line with some of Stone Blue's observations).

 

 

That's a flag and a lander shuttle, suspended approximately 700m above the ground. Meanwhile, there's a rover on the ground below (you can see the lights to the right of the NavBall).