Need help with the phsics system, (about collision, control, camera & terrain)

Troubleshooting physics
1

hey, everyone. i am learning the jme and met some problems. can anyone help me?


  1. what kind of control and collision shape should i use? how to setup the camera ?

    the object is just like a jet plane, but with out things like wheels.

    In fact, it is a wing-in-ground vehicle/groud effect vehicle, control system like jet, but can fly at a low speed when very near the ground, become a jet when speed is very height and the vehicle works lisk a boat when the speed is too low.

    You can see the simplifed model below to know where the main forces are.(T1 is the raise force caused by the main part of the vehicle, T2, T3 are the raise forces caused by the wing parts, T5, T6 are the forces caused by the rudder, T7, T8 are the trust forces and T4, which is not appeared in the graph is a force caused by the airbrake)



    http://www.knfproject.net/u1.jpg



    In our first phase, we don’t consider the situation that when the speed was too slow, and there is no airbrake too. i tried using a box collision shape and RigidBodyControl, and a TerrainGrid. but the vehicle always collides with the terrain and springs like a rubber. Should I use the VehicleControl instead of the RigidBodyControl? and the camera now is just at the same position as the vehicle center. but i hope the camera works like the first persion view in flight simulate games, but how?


  2. when we don’t give a inital speed to the vehicle. the vehicle falt to the ground and knocked back to the sky, just like a spring. but we want to make the terrain more similar to mud, which can absorb most of the impluse. how to implement this kind of feature.
2

Think well if you want a physics simulation at all. Humans needed 100.000’s of years to learn walking on two legs with the physics around them, steering a space ship is easier but also not exactly easy. Its obviously much easier making the ship move “how you want it” than counter-acting forces all the time. Anyway use a RigidBody if you don’t want it to slide like the hovercraft example.

3
@normen said:
Think well if you want a physics simulation at all. Humans needed 100.000's of years to learn walking on two legs with the physics around them, steering a space ship is easier but also not exactly easy. Its obviously much easier making the ship move "how you want it" than counter-acting forces all the time. Anyway use a RigidBody if you don't want it to slide like the hovercraft example.


i see. i'll try to use an easier way to see the effect.
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btw, any idea about the 2nd problem?

5

restitution is the general parameter for “bounciness”

6

Normen is probably right, as usual



I always appreciate a good free-body diagram though :slight_smile: