Thanks Anton_S,
But I would like a radar of this style !! Of my model Sketchyphysics for MsPhysics!

https://3dwarehouse.sketchup.com/model/dc1774c9431e40bad9689dffd6e75da7/Avion-2-sp-No-Gyro

Avion+02.skp

Hello, I would like to create text that does not of the world of the !! Example: the objects far from the center of the axis!

And I would like to create lines, shapes, points !! A radar...

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To get local velocity, along the body's Y-axis, you got to transform the global velocity relative to the body first, then get the Y component:
CODE: SELECT ALL
loc_vel = this.get_velocity.transform(this.get_normal_matrix.inverse)
vy = loc_vel.y

Regards,
Anton

===================
problem!!!!!!

Bonjour,
Je voudrais lire la vitesse D'un corps sur l'axe Y interne,no axe Y mondiale !!!
J'ai essayé get_velocity...
set_var("speed_Y",????)

Hello,
I would like to read the speed of a body on the internal Y-axis, no Y-axis world!
I tried: get_velocity...
set_var("speed_Y",????)

erreur Masse !!!! v1.0.0
no reset position ! big masse

https://youtu.be/VEXXFDndSOo

Final base

https://youtu.be/QaAZ_g9BE5M

https://3dwarehouse.sketchup.com/model.html?id=1da61a91-78ca-440a-b0dd-6663af7d3fec

https://youtu.be/wmR47dOcJn4

my project

https://youtu.be/yZW0bWTSleQ

@Anton_S
@body.set_omega([Internal body axis , 0, axes in global space]) ???

ex:
*onStart{
@body = simulation.find_body_by_name('body')
}

onUpdate{
r_body = @body.get_matrix

ax = Geom::Vector3d.new([key('up'), 0, 0]).transform(r_body)

@body.set_omega([ax.x, 0, key('right')])
}*