SDK Question Touchdown points definition 2016

[gattispilot]

Ok Thanks. Makes sense. Not sure why the LEr ends up upside down. I reverse the order of the last 2 points and no change

 

[gattispilot]

I also noticed if I crash a DG it eventually ends upside down.

I have several ground vessels but not sure what to change on the touchdown points.

 

[gattispilot]

So I tried my Curiosity Rover in 2016.

It just seem to sink into the surface. Also notice the whole shadow. One thing I also noticed on the pop up window the "X" is not there to close it.

static const int ntdvtx = 3;
static TOUCHDOWNVTX tdvtx[ntdvtx] = {
	{ _V(0, .001, 1.5), 1e6, 1e5, 3.2, 0.8 },
	{ _V(-2, .001, -2.6), 1e6, 1e5, 3.2, 0.4 },
	{ _V(2, .001, -2.6), 1e6, 1e5, 3.2, 0.4 }//,
	//	{ _V(-2, -2.164, 1.5), 1e6, 1e5, 3.2, 0 },
	//	{ _V(2, -2.164, 1.5), 1e6, 1e5, 3.2, 0 },
	//	{ _V(-2, 1.6, -2.6), 1e6, 1e5, 3.2, 0 },
	//	{ _V(2, 1.6, -2.6), 1e6, 1e5, 3.2, 0 },
	//	{ _V(-2, 1.6, 1.5), 1e6, 1e5, 3.2, 0 },
	//	{ _V(2, 1.6, 1.5), 1e6, 1e5, 3.2, 0 }
};

 

[Donamy]

couldn't you raise the touch points, to be even with the shadow ?

 

[gattispilot]

Well yes. But shouldn't the mesh block the shadow below it?

I have tried different setting to get the vessel above or less in the ground and no success

 

[DaveS]

Well yes. But shouldn't the mesh block the shadow below it?

I have tried different setting to get the vessel above or less in the ground and no success

Are you sure it's the shadow that is obscuring the mesh and not the terrain? To me it looks like it's the terrain that is doing all the obscuring and not the shadow. To test this you can try disabling vessel shadows from the Visual Effects tab.

 

[gattispilot]

Here she is with vessel shadows turned off. She is sinking in the surface.

I would think I would be higher up. It would be nice to ride on the surface without flipping

 

[gattispilot]

So is there a flat spot to test what the landing points look like. So the wheels are just above the surface.

It seems that the thrust is greater in 2016. HAs anyone gotten a vessel to drive on the surface without flipping?

 

[jedidia]

DanStephs UCGO cars still drive fine in 2016, actually (you just can't enter the cockpit, that ctds. But the driving model is stable).

The problem with sinking into the ground is probably located here:

{ _V(0, [B].001[/B], 1.5), 1e6, 1e5, 3.2, 0.8 },
	{ _V(-2, [B].001[/B], -2.6), 1e6, 1e5, 3.2, 0.4 },
	{ _V(2, [B].001[/B], -2.6), 1e6, 1e5, 3.2, 0.4 }

Basically, the y-position of your points is at the height of the vessels CoG. Which I would not expect to be at the bottom of the wheels.

Another problem you are going to have with the whole arrangement, which I just noticed myself while working with dynamic touchdown points, is that Scenario Editor will place the vessel according to only the first three touchdown points. But as soon as you make a move, Orbiter considers all the touchdown points, which in your case are way lower than the three initial ones. The expected result is the vessel being flung upwards as soon as it moves after being placed with scenario editor.

 

[gattispilot]

Ok. Here is the image of the rover.

You can see the touchdown points. So the touchdown points are not where the wheel contact the ground?

 

[jedidia]

No, if the mesh is positioned like that, they are at the correct height. The other ones at -2.164 wouldn't be, though.

 

[gattispilot]

Thanks. So how do I get it to drive on the surface. The thrust is at 0,0,0. Without the flipping.

I did notice that effect. When the vessel is added no issues but when thrust is applied it tends to sink down a bit.

On Dans cars How can you drive them if you can't get them in? Depending on which pad they do sink in.

 

[jedidia]

On Dans cars How can you drive them if you can't get them in? Depending on which pad they do sink in.

Just from external view. They sink in a little bit depending on evenness of the terrain, that's unavoidable, but I haven't seen anything extreme.

 

[gattispilot]

Ok. So not sure if adjusting the dampness would help. In the real world. If the dampness was weak on a car. The car would be bouncing. I guess if enough bounce it could leave the surface. Maybe that is whats happening.

Ideally the vessel should hug the surface.

 

[mike-c]

touchdown points in cfg

Hope i didn't missed it in orbiter2016's doc:
is there a new Syntax/semantic for defining TD-Points (n>4) in a (Vessel).cfg

Thank's in advance :tiphat:

 

[N_Molson]

below standard sea-level.

"datum" as they say

 

[gattispilot]

Yes. There is a new definition:http://www.orbiter-forum.com/showthread.php?p=541512&postcount=4

So maybe it is not the touchdown points that cause my ground vessels to flip,....

But maybe the dampness....
"Low stiffness makes the vessel jump more. It's the equivalent of a soft spring, so exerts a low force at large spring displacement.

However, be careful when increasing the stiffness. A higher stiffness also increases the eigenfrequency of the system, which can lead to numerical instabilities in particular at higher time accelerations (large forces even at small displacements).

Regarding damping: look up "critical damping" for computing damping values that return the spring to equilibrium fastest and don't induce oscillations. "


https://en.wikipedia.org/wiki/Damping

 

[mike-c]

In the process of getting a Velcro-Atlas flying i got some strange behavioure on launchpad: sinking into the ground like a needle, tipping over and then lying flat on the ground, bouncing a few meters into the air; all immediate at sim start.

After some trying i found these params working for a middlesize rocket:
static TOUCHDOWNVTX tdvtx0[ntdvtx0] = {
{currTD1, 1e8, 1e6, 3, 1},
{currTD2, 1e8, 1e6, 3, 1},
{currTD3, 1e8, 1e6, 3, 1},
{_V(0.0,0.0, 1.0), 1e8, 1e6, 3},
};

tdvtx0[3] is constant, since i cannot yet hand it over to the vessel from
Config\Vessels\*.cfg

 

[gattispilot]

Ok. I can't figure this out.

So the mesh is oriented correctly.

DWORD ntdvtx = 3;
static TOUCHDOWNVTX tdvtx[3] = {
	{ _V(0, .001, 20), 1e5, 1e2, 0.5, 0.005 },
	{ _V(-15, .001, -20), 1e5, 1e2, 0.5, 0.005 },
	{ _V(15, .001, -20), 1e5, 1e2, 0.5, 0.005 },
	//{ _V(0, 5, 0), 1e5, 1e2, 0.5 }// new point just to make a closed shape (more are not needed as the crawler is unlikely to get upside down)
};

void SLSCRAWLER::clbkSetClassCaps(FILEHANDLE cfg) {
	// physical specs
	SetSize(6.08);
	SetEmptyMass(MASS);
	SetCW(0.9, 0.9, 2, 1.4);
	SetWingAspect(0.1);
	SetWingEffectiveness(0.1);
	SetCrossSections(_V(12.16, 15.99, 9.39));
	SetRotDrag(_V(0.1, 0.1, 0.1));
	if (GetFlightModel() >= 1) {
		SetPitchMomentScale(1e-4);
		SetBankMomentScale(1e-4);
	}
	SetPMI(_V(3.75, 3.48, 2.23));
	SetTrimScale(0.05);
	SetCameraOffset(_V(0, .7, 3.121));
	SetTouchdownPoints(tdvtx, ntdvtx);

I opened a scenario and added it and located it at the sh02;

SH-02:ShuttleA
  STATUS Landed Earth
  BASE Cape Canaveral:5
  POS -80.6745295 28.5197189
  HEADING 100.00
  ALT 2.912
  AROT -62.051 -79.897 124.244
  AFCMODE 7
  PRPLEVEL 0:1.000000 1:1.000000
  NAVFREQ 0 0
  XPDR 0
  PODANGLE 0.0000 0.0000
  DOCKSTATE 0 0.0000
  GEAR 0 0.0000
  PAYLOAD MASS 0.0 0
  ATTREF 0 0 0
  ADI_LAYOUT 0
END
crawler:SLSCRAWLER
  STATUS Landed Earth
  POS -80.6745300 28.5197190
  HEADING 100.00
  ALT -60.000
  AROT -28.841 8.183 95.517
  AFCMODE 7
  PRPLEVEL 0:1.000000
  NAVFREQ 0 0
END

Notice the ALT -60

So the craft is below the surface and rotated straight up. The points work in sc4

 

[Urwumpe]

Syntax error.

Also ALT is no standard parameter of Orbiter.