BetterCharacterControl jumping on plain surface

Troubleshooting physics
1

hello. Im struggling with BetterCharacterControl jumping for no reason on plain surface (made of tiles 3x3 meters wide in jmonkey, spaced 3 meters from each other so they make a board). here is the code player + camera code:

public class StartGameState extends AbstractAppState{

private final Node rootNode;
private final Node localRootNode = new Node("GameStart");
private final AssetManager assetManager;
private final InputManager inputManager;
Node playerNode;
Node playerLookAtNode;
CameraNode camNode;
public BulletAppState bulletAppState;
private final FlyByCamera flyCam;
private final Camera cam;
private BetterCharacterControl playerCharacterControl;
boolean forward = false;
boolean backward = false;
boolean left = false;
boolean right = false;
private ChaseCamera chaseCam;
private Vector3f playerWalkDirection;




public StartGameState(SimpleApplication app){
    rootNode = app.getRootNode();
    assetManager = app.getAssetManager();
    inputManager = app.getInputManager();
    flyCam = app.getFlyByCamera();
    cam = app.getCamera();
    
}

@Override
public void initialize(AppStateManager stateManager, Application app){
    super.initialize(stateManager, app);
    
    rootNode.attachChild(localRootNode);
    
    bulletAppState = new BulletAppState();
    bulletAppState.setThreadingType(BulletAppState.ThreadingType.PARALLEL);
    bulletAppState.setDebugEnabled(true);
    stateManager.attach(bulletAppState);
    initPlayer();
    initKeys();
    DirectionalLight sun = new DirectionalLight();
    sun.setDirection(new Vector3f(-0.1f, -0.7f, -1.0f));
    rootNode.addLight(sun);


}
public void initKeys(){

inputManager.addMapping("RotateCameraRight", new MouseAxisTrigger(MouseInput.AXIS_X,true));
inputManager.addMapping("RotateCameraLeft", new MouseAxisTrigger(MouseInput.AXIS_X,false));
inputManager.addMapping("RotateCameraUp", new MouseAxisTrigger(MouseInput.AXIS_Y,true));
inputManager.addMapping("RotateCameraDown", new MouseAxisTrigger(MouseInput.AXIS_Y,false));
inputManager.addMapping("Forward", new KeyTrigger(KeyInput.KEY_W));
inputManager.addMapping("Backward", new KeyTrigger(KeyInput.KEY_S));
inputManager.addMapping("Left", new KeyTrigger(KeyInput.KEY_A));
inputManager.addMapping("Right", new KeyTrigger(KeyInput.KEY_D));
inputManager.addMapping("test", new KeyTrigger(KeyInput.KEY_K));




inputManager.addListener(actionListener, "Forward");
inputManager.addListener(actionListener, "Backward");
inputManager.addListener(actionListener, "Left");
inputManager.addListener(actionListener, "Right");
inputManager.addListener(actionListener, "test");



}

public void initPlayer(){
playerCharacterControl = new BetterCharacterControl(0.35f,1.8f,1f);

flyCam.setEnabled(false);
playerNode = new Node();

playerCharacterControl.setJumpForce(new Vector3f(0,2.5f,0));
getPhysicsSpace().add(playerCharacterControl);
getPhysicsSpace().addAll(playerNode);
playerCharacterControl.setGravity(new Vector3f(0,-5,0));
playerNode.addControl(playerCharacterControl);
playerCharacterControl.warp(new Vector3f(0,0,0));

playerLookAtNode = new Node();
playerNode.attachChild(playerLookAtNode);
playerLookAtNode.move(0,1.5f,0);
rootNode.attachChild(playerNode);


flyCam.setEnabled(true);
camNode = new CameraNode("Camera Node", cam);
camNode.setControlDir(ControlDirection.SpatialToCamera);
playerNode.attachChild(camNode);
camNode.setLocalTranslation(new Vector3f(0, 1.5f, 0));
camNode.lookAt(playerLookAtNode.getLocalTranslation(), Vector3f.UNIT_Y);
inputManager.setCursorVisible(false);

}

private final ActionListener actionListener = new ActionListener() {
    @Override
    public void onAction(String name, boolean keyPressed, float tpf) {
      if(name.equals("test")){
      System.out.print(inputManager.getCursorPosition().x);
      camNode.setEnabled(false);
      }
      
      if(name.equals("Forward")){
      if(keyPressed){
          forward = true;
                }else {
          forward = false;
        }
      }
      
      if(name.equals("Backward")){
      if(keyPressed){
          backward = true;
      }else {
          backward = false;
        }
      }
      
         if(name.equals("Left")){
      if(keyPressed){
          left = true;
      }else {
          left = false;
        }
      }
         
      if(name.equals("Right")){
      if(keyPressed){
          right = true;
      }else {
          right = false;
        }
      }
      
      
    }
};

private final AnalogListener analogListener = new AnalogListener() {
    @Override
    public void onAnalog(String name, float value, float tpf) {
    }
};

@Override
public void cleanup(){
rootNode.detachChild(localRootNode);

super.cleanup();
}
@Override
public void update(float tpf) {
    playerCharacterControl.setWalkDirection(new Vector3f(0,0,0));
    playerWalkDirection = cam.getDirection();
    playerWalkDirection.setY(0);
    playerCharacterControl.setViewDirection(new Vector3f(playerWalkDirection));
    if(forward){
    playerCharacterControl.setWalkDirection(playerWalkDirection.mult(10));
    } else if(backward){
    playerCharacterControl.setWalkDirection(playerWalkDirection.mult(2).negate());
    }

    System.out.println(playerNode.getWorldTranslation());}}

and here is the terrain generation code:

import com.jme3.app.Application;
import com.jme3.app.SimpleApplication;
import com.jme3.app.state.AbstractAppState;
import com.jme3.app.state.AppStateManager;
import com.jme3.asset.AssetManager;
import com.jme3.bullet.BulletAppState;
import static com.jme3.bullet.PhysicsSpace.getPhysicsSpace;
import com.jme3.bullet.control.BetterCharacterControl;
import com.jme3.bullet.control.RigidBodyControl;
import com.jme3.input.ChaseCamera;
import com.jme3.input.FlyByCamera;
import com.jme3.input.InputManager;
import com.jme3.input.KeyInput;
import com.jme3.input.MouseInput;
import com.jme3.input.controls.ActionListener;
import com.jme3.input.controls.AnalogListener;
import com.jme3.input.controls.KeyTrigger;
import com.jme3.input.controls.MouseAxisTrigger;
import com.jme3.light.DirectionalLight;
import com.jme3.material.Material;
import com.jme3.math.FastMath;
import com.jme3.math.Vector3f;
import com.jme3.renderer.Camera;
import com.jme3.scene.CameraNode;
import com.jme3.scene.Geometry;
import com.jme3.scene.Node;
import com.jme3.scene.Spatial;
import com.jme3.scene.shape.Box;
import com.jme3.texture.Texture;
import java.util.ArrayList;

public class TerrainGenerationState extends AbstractAppState{
private final Node rootNode;
private final Node terrainRootNode = new Node("TerrainRootNode");
private  ArrayList<String> tileModels = new ArrayList<String>();
private final AssetManager assetManager;
private BulletAppState bulletAppState;
private Spatial tileSpatial;
private RigidBodyControl tileRigidBody;
private Vector3f tileOffsetVector;
private final AppStateManager stateManager;

public TerrainGenerationState(SimpleApplication StartGameState){
    rootNode = StartGameState.getRootNode();
    assetManager = StartGameState.getAssetManager();
    stateManager = StartGameState.getStateManager();
}

@Override
public void initialize(AppStateManager stateManager, Application app){
    super.initialize(stateManager, app);
    initTileModels();
    initMap();

}


public void initTileModels(){
    
tileModels.add("Models/Floor1/Floor1.j3o");
}
public void initMap(){   
    
    for(int i=-5;i<=4;i++){
    int k = 0;  //arraylist index (the one containing model paths for terrain)
    int r = -15; //row vector
    tileOffsetVector = new Vector3f(3*i,-2,r);
    tileSpatial = assetManager.loadModel(tileModels.get(k));
    tileSpatial.move(tileOffsetVector);         
    tileRigidBody = new RigidBodyControl(0);
    tileSpatial.addControl(tileRigidBody);
    getPhysicsSpace().add(tileSpatial);
    rootNode.attachChild(tileSpatial);
    
    tileOffsetVector = new Vector3f(3*i,-2,r+3);
   tileSpatial = assetManager.loadModel(tileModels.get(k));
   tileSpatial.move(tileOffsetVector);
     tileRigidBody = new RigidBodyControl(0);
    tileSpatial.addControl(tileRigidBody);
    getPhysicsSpace().add(tileSpatial);
   rootNode.attachChild(tileSpatial);

    tileOffsetVector = new Vector3f(3*i,-2,r+6);
   tileSpatial = assetManager.loadModel(tileModels.get(k));
    tileSpatial.move(tileOffsetVector);
      tileRigidBody = new RigidBodyControl(0);
    tileSpatial.addControl(tileRigidBody);
    getPhysicsSpace().add(tileSpatial);
    rootNode.attachChild(tileSpatial);

    tileOffsetVector = new Vector3f(3*i,-2,r+9);
    tileSpatial = assetManager.loadModel(tileModels.get(k));
    tileSpatial.move(tileOffsetVector);
      tileRigidBody = new RigidBodyControl(0);
    tileSpatial.addControl(tileRigidBody);
    getPhysicsSpace().add(tileSpatial);
    rootNode.attachChild(tileSpatial);

    tileOffsetVector = new Vector3f(3*i,-2,r+12);
    tileSpatial = assetManager.loadModel(tileModels.get(k));
    tileSpatial.move(tileOffsetVector);
      tileRigidBody = new RigidBodyControl(0);
    tileSpatial.addControl(tileRigidBody);
    getPhysicsSpace().add(tileSpatial);
    rootNode.attachChild(tileSpatial);

    tileOffsetVector = new Vector3f(3*i,-2,r+15);
    tileSpatial = assetManager.loadModel(tileModels.get(k));
    tileSpatial.move(tileOffsetVector);
      tileRigidBody = new RigidBodyControl(0);
    tileSpatial.addControl(tileRigidBody);
    getPhysicsSpace().add(tileSpatial);
    rootNode.attachChild(tileSpatial);

    tileOffsetVector = new Vector3f(3*i,-2,r+18);
    tileSpatial = assetManager.loadModel(tileModels.get(k));
    tileSpatial.move(tileOffsetVector);
      tileRigidBody = new RigidBodyControl(0);
    tileSpatial.addControl(tileRigidBody);
    getPhysicsSpace().add(tileSpatial);
    rootNode.attachChild(tileSpatial);

    tileOffsetVector = new Vector3f(3*i,-2,r+21);
    tileSpatial = assetManager.loadModel(tileModels.get(k));
    tileSpatial.move(tileOffsetVector);
      tileRigidBody = new RigidBodyControl(0);
    tileSpatial.addControl(tileRigidBody);
    getPhysicsSpace().add(tileSpatial);
    rootNode.attachChild(tileSpatial);

    tileOffsetVector = new Vector3f(3*i,-2,r+24);
    tileSpatial = assetManager.loadModel(tileModels.get(k));
    tileSpatial.move(tileOffsetVector);
      tileRigidBody = new RigidBodyControl(0);
    tileSpatial.addControl(tileRigidBody);
    getPhysicsSpace().add(tileSpatial);
    rootNode.attachChild(tileSpatial);

    tileOffsetVector = new Vector3f(3*i,-2,r+27);
    tileSpatial = assetManager.loadModel(tileModels.get(k));
    tileSpatial.move(tileOffsetVector);
      tileRigidBody = new RigidBodyControl(0);
    tileSpatial.addControl(tileRigidBody);
    getPhysicsSpace().add(tileSpatial);
    rootNode.attachChild(tileSpatial);
    
    }
}

@Override
public void cleanup(){
rootNode.detachChild(terrainRootNode);

super.cleanup();
}
@Override
public void update(float tpf) {}}

i am fairly sure i am missing something here but i am not sure what it might be, as the tiles are perfectly plain (they are 2d planes 3x3 meters in blender which is exactly 3x3 in jmonkey as far as i know), they are spaced 3 meters between each other (so they fit perfectly) and playerWalkDirection vector Y variable is always set to 0 before moving, so there is literally nothing to bounce off. Here is the playerNode (which betterCharacterControl has control over) translation, to show that this is precisely a matter of physics body bouncing:
coords
the middle one is of course Y value.

2

Hi, a list of things to do/check:

  • Try with one tile and see if collision still doesn’t work.
  • Reduce your code, because there is a lot of copy paste.
  • Specify what physics libraries and versions you use.
  • Check if the physicsspace instance is the same as the the created one with the bulletAppState.
  • try: remove the moving the spatial directly, move it using the physicsengine ‘setPhysicsLocation’ after you have added it to the physics space.
  • Include video of what is happening as I don’t know what you mean specifically with bouncing
1 Like
3

This may be related (a very old topic of mine)
BetterCharacterControl acts like trampoline? - Troubleshooting / physics - jMonkeyEngine Hub

Basically, if using BCC, the mesh vertices cannot be larger than the collision box of the BCC collision shape.

4

Thank you for answering!
I checked if this happens when the player moves on one tile, and the thing that seems to cause the jumping are the “edges” ( the places when the triangles connect in the model). What can i do against this?

5

also thank you very much for advice

6

screenshot
screenshot1920×1080 60.9 KB

this is how big are the tiles compared to the betterCharacterControl, and the jumping occurs when going through the places where the triangles connect (these blue lines)

7

Has the issue been solved?

8

Sadly no, the project was abandoned soon after.

1 Like