HelloTerrain Physics

Troubleshooting General Help
1

Hi,

I’ve been going through the jmonkey tutorials and I’m trying to add in physics (collision detection) to the tutorial “HelloTerrain”. So far I’ve managed to create a player (encapsulate the flycam) and add in gravity, the problem is i can’t seem to get collision detection between the terrain and the player so my player keeps falling through the mesh itself. I’m now only stuck on an error that i can’t seem to fix, here is the code i’m having trouble with so far:





[java]

import com.bulletphysics.collision.broadphase.Dbvt.Node;

import com.bulletphysics.collision.shapes.CollisionShape;

import com.jme3.bounding.BoundingBox;

import com.jme3.bullet.BulletAppState;

import com.jme3.bullet.collision.shapes.BoxCollisionShape;

import com.jme3.bullet.collision.shapes.SphereCollisionShape;

import com.jme3.bullet.control.RigidBodyControl;

import com.jme3.bullet.objects.PhysicsCharacter;

import com.jme3.bullet.util.CollisionShapeFactory;



public class Main extends SimpleApplication implements ActionListener {



private TerrainQuad terrain;



public static void main(String[] args) {

Main app = new Main();

app.start();

}

public void simpleInitApp() {

bulletAppState = new BulletAppState();



stateManager.attach(bulletAppState);





AbstractHeightMap heightmap = null;

Texture heightMapImage = assetManager.loadTexture(

“Textures/Terrain/splat/mountains512.png”);

heightmap = new ImageBasedHeightMap(ImageToAwt.convert(heightMapImage.getImage(), false, true, 0), 1f);

heightmap.load();



int patchSize = 65;

terrain = new TerrainQuad(“my terrain”, patchSize, 513, heightmap.getHeightMap());



com.jme3.bullet.collision.shapes.CollisionShape sceneShape = CollisionShapeFactory.createMeshShape(terrain);



terrain.setMaterial(mat_terrain);

terrain.setLocalTranslation(0, -100, 0);

terrain.setLocalScale(2f, 1f, 2f);

Node terrain_holder = new Node();

rootNode.attachChild(terrain);

CollisionShape sceneShape =

CollisionShapeFactory.createMeshShape(terrain.getSpatial());



terrain.updateModelBound();

}

}[/java]



Any help or guidance to solve this problem will be very appreciative,

cheers!

2

Theres a test class for exactly that.

3

i belive you forgot to add the collision shape to the bulletappstate:



bulletAppState.getPhysicsSpace().add(sceneShape);



also, why are you doing this? :

CollisionShape sceneShape = CollisionShapeFactory.createMeshShape(terrain.getSpatial());



seems pointless to me… maybe you were trying to debug or something?



and terrain_holder is not used at all…



finally, i belive normen is talking about this tutorial:

https://wiki.jmonkeyengine.org/legacy/doku.php/jme3:beginner:hello_collision



hope this helps…



cheers…

4

I’ve got it working! thanks dixil, much appreciated!!

cheers lads :slight_smile: