Jets with heavy noses

[tanelorn]

Hi all. I am adjusting the physics of the Desert Combat SU-25 to make it more bot-friendly for the new release of DCR. I'm running into issues with the jet being noseheavy - in other words, if you let off the stick, the nose tips toward the ground. I'm trying to figure out wether this is simply a lift issue, or if there is an imbalance of where the lift is occurring.

I want to give the jet significant inertia to make it feel like a big heavy jet, but also keep it in the air. Could anyone with vehicle physics coding experience help me out on this one? Specifically, can you tell me wether the position of the winglift and flaplift has any effect on the handling of the vehicle? Perhaps those lift objects are too far back on the plane and cause the nose to tip down as a result...

[freddy]

does it always drop the nose or does it vary with different speed?

[tanelorn]

Even at high speed it will tip down.

I wish the MDT had a definition for some of the properties related to this. There are a couple that I suspect are directly related to speed/lift ratio, such as:

ObjectTemplate.setRegulateToLift 4.91
ObjectTemplate.setWingToRegulatorRatio 1

I also found this interesting:

Code: Select all

rem *** SU-25FlapLeftMiddle ***
ObjectTemplate.create Wing SU-25FlapLeftMiddle
ObjectTemplate.setNetworkableInfo SU-25_wing_info
ObjectTemplate.geometry SU-25_Flap_Left_Middle_M1
[b]ObjectTemplate.setMinRotation 0/-2/0
ObjectTemplate.setMaxRotation 0/2/0[/b]
ObjectTemplate.setMaxSpeed 0/30/0
ObjectTemplate.setAcceleration 0/120/0
ObjectTemplate.setPitchOffset 0.5
ObjectTemplate.setPositionOffset 0/0/0
rem ObjectTemplate.setWingLift 0.5
ObjectTemplate.setWingLift 2.5
ObjectTemplate.setFlapLift 2.5
ObjectTemplate.setRegulateToLift 4.91
ObjectTemplate.setWingToRegulatorRatio 1

There is no input assigned to this, yet they are given rotations...

[Jeronimo]

Maybe there once was, but it has been taken out.

You could try adjusting it to

Code: Select all

ObjectTemplate.setMinRotation 0/10/0
ObjectTemplate.setMaxRotation 0/10/0

Maybe that solves the nose drop prob already.

[Dennis|8749236]

is the mass to heavy???

[tanelorn]

is the mass to heavy???

That's my big question... is the mass to lift ratio what is causing it? It depends on how the game handles lift. If the mass is too high and lift is too low, does that affect wether the nose can stay level, or does it simply affect how much climb you can get out of the aircraft?

I'm going to experiment with these properties, but first I wanted to ask you all if you know for certain wether the nose dropping can be due to the flaps / wings being in a certain place on the body, or if it is an effect of mass-lift ratios in general.

[Dennis|8749236]

-.-
go to BF1942, and edit BF109's mass to 10000000
and try to fly it... and u got answer...

[freddy]

mass has nothing to do with it. the mesh is the first thing, different mesh different flight charatistics, next are wings and there positions.

i´m not familiar with DC planes but the bf42 planes use a bodywing, i belive this is worth checking

Code: Select all

rem *** CorsairBodyWingVertical ***
ObjectTemplate.create Wing CorsairBodyWingVertical
ObjectTemplate.setAutomaticReset 1
ObjectTemplate.setPositionOffset 0/0/-0.1
ObjectTemplate.setWingLift 2
ObjectTemplate.setFlapLift 0

as you can see it has no networkinfo and no geometry, its propably there just to adjust flight charatistics

[tanelorn]

Yes I did find that in the code. It has a rather high lift: 10. But the plane mass is quite high also: 5000. There are 7 defined lift surfaces, and each has around 2 lift apiece. Add that to the bodylift of 10, and you get a total of 14+10 = 24 lift total.

[freddy]

i gave a plane more mass once and it felt like it had a stronger engine that was all. always worth a try tho.