+1 vote

Imagine a cube with 4 thrusters on each face, like on a small space-capsule.
These generate thrust in 12 directions (Forward, Backward, Left, Right, Up, Down, +Yaw, -Yaw, +Pitch, -Pitch, +Roll, -Roll)

Thrust for each direction is calculated and (should be) implemented each frame.

My rotations (Yaw, Pitch and Roll) work like a charm ... but I'm too stupid to integrate the linear thrust (generated local to object's orientation) into a single global translation for my object.

extends KinematicBody

var Decay:float = 2.0;
var CurrDecay:float = 0.0;

var ThrustX:float = 0.0;
var ThrustY:float = 0.0;
var ThrustZ:float = 0.0;
var ThrustMax:float = 50.0;#Meters/Second

var RotateY:float = 0.0;
var RotateX:float = 0.0;
var RotateZ:float = 0.0;
var RotateMax:float = 10.0;#Degrees/Second

func _process(delta):

if Input.is_action_pressed("Shift"):

if Input.is_action_pressed("Pitch+"):
RotateX -= (RotateMax-abs(RotateX)) * delta;
if Input.is_action_pressed("Pitch-"):
RotateX += (RotateMax-RotateX) * delta;

if Input.is_action_pressed("ThrustLeft"):
ThrustX -= (ThrustMax-abs(ThrustX)) * delta;
if Input.is_action_pressed("ThrustRight"):
ThrustX += (ThrustMax-ThrustX) * delta;

if Input.is_action_pressed("ThrustUp"):
ThrustY += (ThrustMax-ThrustY) * delta;
if Input.is_action_pressed("ThrustDown"):
ThrustY -= (ThrustMax-abs(ThrustY)) * delta;

else:

if Input.is_action_pressed("ThrustFront"):
ThrustZ -= (ThrustMax-abs(ThrustZ)) * delta;
if Input.is_action_pressed("ThrustBack"):
ThrustZ += (ThrustMax-ThrustZ) * delta;

if Input.is_action_pressed("Yaw+"):
RotateY += (RotateMax-RotateY) * delta;
if Input.is_action_pressed("Yaw-"):
RotateY -= (RotateMax-abs(RotateY)) * delta;

if Input.is_action_pressed("Roll+"):
RotateZ -= (RotateMax-abs(RotateZ)) * delta;
if Input.is_action_pressed("Roll-"):
RotateZ += (RotateMax-RotateZ) * delta;

#DAMPEN
CurrDecay = delta*Decay;
RotateX = lerp(RotateX,0.0,CurrDecay);
RotateY = lerp(RotateY,0.0,CurrDecay);
RotateZ = lerp(RotateZ,0.0,CurrDecay);
ThrustX = lerp(ThrustX,0.0,CurrDecay);
ThrustY = lerp(ThrustY,0.0,CurrDecay);
ThrustZ = lerp(ThrustZ,0.0,CurrDecay);

#EXECUTE

#CRAPPY MISGUIDED LOW-IQ ATTEMPT OF TRANSLATION:
var ThrustVector = Vector3(ThrustX,ThrustY,ThrustZ);# ???
Velocity = Velocity * ThrustVector;# ???
global_translate(Velocity);# ???
#move_and_collide(Velocity);# ???
#translate(Velocity);# ???

in Engine
recategorized

If in your submarine (yellow, isn't it?) the forward direction is -z then you get the global vector3 with global_transform.basis.z * -1.

You can exchange z with i.e. y if you want an up/down vector.

by (3,358 points)
selected by

Thanks for your response ... but it dosn't help me, as I don't know what to do with the information.
And yes, it might be yellow :P

That is your"Thrustvector" (gdscript style)

Oh, I see. I just checked your code a bit closer. I am more used to the physics approach where you can add multiple impulses.

So, if you got Thrust values for the 3 axes then you can multiply each value with each global_transform.basis.x/y/z. Then you could add thee resulting vector3's to get one vector3.

So similar to this:
(global_transform.basis.x * ThrustX) + (global_transform.basis.y * ThrustY) + (global_transform.basis.z * ThrustZ)

You could add this summed up vector to your velocity but you should reduce/damp your velocity at the same time (draft of water). Reducing of the velocity should be a small value relative to delta and the square of your velocity.

Here's the "official" info about working with Transforms:
https://docs.godotengine.org/en/stable/tutorials/3d/using_transforms.html

And here's my attempt to create a kind of "cheat sheet" for transforms:
https://godotforums.org/discussion/18480/godot-3d-vector-physics-cheat-sheet

Perhaps it helps.

Thank you! ... your input guided me to a working solution:

extends KinematicBody#User/Model

var Drag:float = 1.0;

var ThrustX:float = 0.0;
var ThrustY:float = 0.0;
var ThrustZ:float = 0.0;
var ThrustMax:float = 5.0;#Meters/Second?
var ThrustDecay:float = 2.0;

var ThrustVector:Vector3 = Vector3(0,0,0);
var MoveVector:Vector3 = Vector3(0,0,0);
var Velocity:Vector3 = Vector3(1,1,1);

var RotateY:float = 0.0;
var RotateX:float = 0.0;
var RotateZ:float = 0.0;
var RotateMax:float = 8.0;#Degrees/Second?

func _physics_process(delta:float) -> void:

if Input.is_action_pressed("Shift"):

if Input.is_action_pressed("Pitch+"):
RotateX -= (RotateMax-abs(RotateX)) * delta;
if Input.is_action_pressed("Pitch-"):
RotateX += (RotateMax-RotateX) * delta;

if Input.is_action_pressed("ThrustLeft"):
ThrustX -= (ThrustMax-abs(ThrustX)) * delta;
if Input.is_action_pressed("ThrustRight"):
ThrustX += (ThrustMax-ThrustX) * delta;

if Input.is_action_pressed("ThrustUp"):
ThrustY += (ThrustMax-ThrustY) * delta;
if Input.is_action_pressed("ThrustDown"):
ThrustY -= (ThrustMax-abs(ThrustY)) * delta;

else:

if Input.is_action_pressed("ThrustFront"):
ThrustZ -= (ThrustMax-abs(ThrustZ)) * delta;
if Input.is_action_pressed("ThrustBack"):
ThrustZ += (ThrustMax-ThrustZ) * delta;

if Input.is_action_pressed("Yaw+"):
RotateY += (RotateMax-RotateY) * delta;
if Input.is_action_pressed("Yaw-"):
RotateY -= (RotateMax-abs(RotateY)) * delta;

if Input.is_action_pressed("Roll+"):
RotateZ += (RotateMax-RotateZ) * delta;
if Input.is_action_pressed("Roll-"):
RotateZ -= (RotateMax-abs(RotateZ)) * delta;

#DAMPEN THRUST
var CurrDecay:float = delta*ThrustDecay;
RotateX = lerp(RotateX,0.0,CurrDecay);
RotateY = lerp(RotateY,0.0,CurrDecay);
RotateZ = lerp(RotateZ,0.0,CurrDecay);
ThrustX = lerp(ThrustX,0.0,CurrDecay);
ThrustY = lerp(ThrustY,0.0,CurrDecay);
ThrustZ = lerp(ThrustZ,0.0,CurrDecay);

#INTEGRATE FORCES
ThrustVector = (global_transform.basis.x*ThrustX) + (global_transform.basis.y*ThrustY) + (global_transform.basis.z*ThrustZ)
MoveVector = Velocity+ThrustVector;
MoveVector = lerp(MoveVector,Vector3(0,0,0),Drag*delta);#Water-drag

#EXECUTE