JMonkeyEngine : Collision detection on dynamically loaded models - java

I am learning JME3 and I managed to create my own height map and modifying some of the example code, etc. Now, I created a very simple 4-wall roofless room with Blender, exported it as a Wavefront .Obj file and loaded it unto my scene (I attacked it to the terrain node.
Now, my terrain has a collision detection applied so the player can move and jump around, but it can also walk right through the walls of my model. All the examples I can find loads an already pre-built scene, and I'm still clueless as to why the player goes right through the loaded model?
Sorry for the big code, but I couldn't see how else I could do otherwise. The physics is applied at the section /** 6. Add physics: */ :
public class Main extends SimpleApplication
implements ActionListener {
private BulletAppState bulletAppState;
private RigidBodyControl landscape;
private CharacterControl player;
private Vector3f walkDirection = new Vector3f();
private boolean left = false, right = false, up = false, down = false;
private TerrainQuad terrain;
private Material mat_terrain;
public static void main(String[] args) {
AppSettings settings = new AppSettings(true);
settings.setResolution(1366, 768);
settings.setFullscreen(true);
Main app = new Main();
app.setSettings(settings);
app.setShowSettings(false);
app.start();
}
#Override
public void simpleInitApp() {
/** Set up Physics */
bulletAppState = new BulletAppState();
stateManager.attach(bulletAppState);
//bulletAppState.getPhysicsSpace().enableDebug(assetManager);
flyCam.setMoveSpeed(200);
setUpKeys();
/** 1. Create terrain material and load four textures into it. */
mat_terrain = new Material(assetManager, "Common/MatDefs/Terrain/Terrain.j3md");
/** 1.1) Add ALPHA map (for red-blue-green coded splat textures) */
mat_terrain.setTexture("Alpha", assetManager.loadTexture("Textures/terrain/island_1_alpha1.png"));
/** 1.2) Add GRASS texture into the red layer (Tex1). */
Texture grass = assetManager.loadTexture("Textures/Terrain/splat/grass.jpg");
grass.setWrap(WrapMode.Repeat);
mat_terrain.setTexture("Tex1", grass);
mat_terrain.setFloat("Tex1Scale", 64f);
/** 1.3) Add DIRT texture into the green layer (Tex2) */
Texture dirt = assetManager.loadTexture("Textures/rocks.jpg");
dirt.setWrap(WrapMode.Repeat);
mat_terrain.setTexture("Tex2", dirt);
mat_terrain.setFloat("Tex2Scale", 32f);
/** 1.4) Add ROAD texture into the blue layer (Tex3) */
Texture rock = assetManager.loadTexture("Textures/Terrain/splat/dirt.jpg");
rock.setWrap(WrapMode.Repeat);
mat_terrain.setTexture("Tex3", rock);
mat_terrain.setFloat("Tex3Scale", 128f);
/** 2. Create the height map */
AbstractHeightMap heightmap = null;
Texture heightMapImage = assetManager.loadTexture("Textures/terrain/island_1.png");
heightmap = new ImageBasedHeightMap(heightMapImage.getImage());
heightmap.load();
/** 3. We have prepared material and heightmap.
* Now we create the actual terrain:
* 3.1) Create a TerrainQuad and name it "my terrain".
* 3.2) A good value for terrain tiles is 64x64 -- so we supply 64+1=65.
* 3.3) We prepared a heightmap of size 512x512 -- so we supply 512+1=513.
* 3.4) As LOD step scale we supply Vector3f(1,1,1).
* 3.5) We supply the prepared heightmap itself.
*/
terrain = new TerrainQuad("my terrain", 65, 513, heightmap.getHeightMap());
/** 4. We give the terrain its material, position & scale it, and attach it. */
terrain.setMaterial(mat_terrain);
terrain.setLocalTranslation(0, -170, 0);
terrain.setLocalScale(2f, 1f, 2f);
rootNode.attachChild(terrain);
/** 4.5. Load some models */
Spatial building = assetManager.loadModel("Models/building1.obj");
Material mat_default = new Material(assetManager, "Common/MatDefs/Misc/ShowNormals.j3md");
building.setMaterial(mat_default);
building.setLocalTranslation(90, 117, 90);
building.setLocalScale(5f, 5f, 5f);
terrain.attachChild(building);
/** 4.6. Load Sky */
rootNode.attachChild(SkyFactory.createSky(assetManager, "Textures/Sky/Bright/BrightSky.dds", false));
/** 4.7. Load water */
// we create a water processor
SimpleWaterProcessor waterProcessor = new SimpleWaterProcessor(assetManager);
waterProcessor.setReflectionScene(rootNode);
// we set the water plane
Vector3f waterLocation = new Vector3f(0, -58, 0);
waterProcessor.setPlane(new Plane(Vector3f.UNIT_Y, waterLocation.dot(Vector3f.UNIT_Y)));
viewPort.addProcessor(waterProcessor);
// we set wave properties
waterProcessor.setWaterDepth(50); // transparency of water
waterProcessor.setDistortionScale(0.05f); // strength of waves
waterProcessor.setWaveSpeed(0.05f); // speed of waves
// we define the wave size by setting the size of the texture coordinates
Quad quad = new Quad(1000, 1000);
quad.scaleTextureCoordinates(new Vector2f(10f, 10f));
// we create the water geometry from the quad
Geometry water = new Geometry("water", quad);
water.setLocalRotation(new Quaternion().fromAngleAxis(-FastMath.HALF_PI, Vector3f.UNIT_X));
water.setLocalTranslation(-500, -58, 500);
water.setShadowMode(ShadowMode.Receive);
water.setMaterial(waterProcessor.getMaterial());
rootNode.attachChild(water);
/** 5. The LOD (level of detail) depends on were the camera is: */
List<Camera> cameras = new ArrayList<Camera>();
cameras.add(getCamera());
TerrainLodControl control = new TerrainLodControl(terrain, cameras);
terrain.addControl(control);
/** 6. Add physics: */
// We set up collision detection for the scene by creating a
// compound collision shape and a static RigidBodyControl with mass zero.*/
CollisionShape terrainShape = CollisionShapeFactory.createMeshShape(terrain);
landscape = new RigidBodyControl(terrainShape, 0);
terrain.addControl(landscape);
terrain.addControl(new RigidBodyControl(CollisionShapeFactory.createMeshShape(building), 0));
// We set up collision detection for the player by creating
// a capsule collision shape and a CharacterControl.
// The CharacterControl offers extra settings for
// size, stepheight, jumping, falling, and gravity.
// We also put the player in its starting position.
CapsuleCollisionShape capsuleShape = new CapsuleCollisionShape(1.5f, 6f, 1);
player = new CharacterControl(capsuleShape, 0.05f);
player.setJumpSpeed(50);
player.setFallSpeed(70);
player.setGravity(100);
player.setPhysicsLocation(new Vector3f(50, 100, 100));
// We attach the scene and the player to the rootnode and the physics space,
// to make them appear in the game world.
bulletAppState.getPhysicsSpace().add(terrain);
bulletAppState.getPhysicsSpace().add(player);
}
/** We over-write some navigational key mappings here, so we can
* add physics-controlled walking and jumping: */
private void setUpKeys() {
inputManager.addMapping("Left", new KeyTrigger(KeyInput.KEY_A));
inputManager.addMapping("Right", new KeyTrigger(KeyInput.KEY_D));
inputManager.addMapping("Up", new KeyTrigger(KeyInput.KEY_W));
inputManager.addMapping("Down", new KeyTrigger(KeyInput.KEY_S));
inputManager.addMapping("Jump", new KeyTrigger(KeyInput.KEY_SPACE));
inputManager.addListener(this, "Left");
inputManager.addListener(this, "Right");
inputManager.addListener(this, "Up");
inputManager.addListener(this, "Down");
inputManager.addListener(this, "Jump");
}
/** These are our custom actions triggered by key presses.
* We do not walk yet, we just keep track of the direction the user pressed. */
public void onAction(String binding, boolean value, float tpf) {
if (binding.equals("Left")) {
if (value) {
left = true;
} else {
left = false;
}
} else if (binding.equals("Right")) {
if (value) {
right = true;
} else {
right = false;
}
} else if (binding.equals("Up")) {
if (value) {
up = true;
} else {
up = false;
}
} else if (binding.equals("Down")) {
if (value) {
down = true;
} else {
down = false;
}
} else if (binding.equals("Jump")) {
player.jump();
}
}
/**
* This is the main event loop--walking happens here.
* We check in which direction the player is walking by interpreting
* the camera direction forward (camDir) and to the side (camLeft).
* The setWalkDirection() command is what lets a physics-controlled player walk.
* We also make sure here that the camera moves with player.
*/
#Override
public void simpleUpdate(float tpf) {
Vector3f camDir = cam.getDirection().clone().multLocal(0.6f);
Vector3f camLeft = cam.getLeft().clone().multLocal(0.4f);
walkDirection.set(0, 0, 0);
if (left) {
walkDirection.addLocal(camLeft);
}
if (right) {
walkDirection.addLocal(camLeft.negate());
}
if (up) {
walkDirection.addLocal(camDir);
}
if (down) {
walkDirection.addLocal(camDir.negate());
}
player.setWalkDirection(walkDirection);
cam.setLocation(player.getPhysicsLocation());
}
}
So, why isn't my model applied to the collision detection?

I have found the answer, here. The solution to the problem is this :
Create a CollisionShape. Create a PhysicsControl by supplying the
CollisionShape and mass. E.g. com.jme3.bullet.control.RigidBodyControl
Add the PhysicsControl to the Spatial. Add the PhysicsControl to the
physicsSpace object. Attach the Spatial to the rootNode, as usual.
(Optional) Implement the PhysicsCollisionListener interface to respond
to PhysicsCollisionEvents if desired.
Therefore, replace
terrain.attachChild(building);
by
rootNode.attachChild(building);
and adding
bulletAppState.getPhysicsSpace().add(building);

Related

Shaking single tile in java (libgdx + TiledMap)

I'm making a clone of old Super Mario and I am trying to shake the brick tile when mario in his little form hits it from below. The concept is taken from a great libgdx tutorial by Brent Aureli and everything he wrote/shown works, however when I made this (seemingly small) modification, the modification itself behaves strange.
Namely, when little mario hits the tile (any brick tile) ALL tiles of this kind get this offset. From my understanding, the access is getCell().getTile().setOffsetY(value) which should mean
get a single cell -> get tile in that cell -> set offset to this one tile that is in the given cell.
Documentation also suggests it should work like that:
https://libgdx.badlogicgames.com/nightlies/docs/api/
replacing tile with null when big mario hits the tile works as intended, so I don't understand why the approach with getCell.getTile doesn't.
Finally, I'm aware that cells are immobile, all I want is a purely cosmetic shift of the actual texture for half a second or so - and that is possible, but in the current state it offsets ALL similar tiles.
For the fun of it I
public class Brick extends InteractiveTile {
private static TiledMapTileSet tileSet;
public Brick(PlayScreen screen, MapObject object) {
super(screen, object);
tileSet = screen.getMap().getTileSets().getTileSet("tileset_gutter");
fixture.setUserData(this);
setCategoryFilter(SuperMario.BRICK_BIT);
}
#Override
public void onHeadHit(Mario mario) {
if(mario.isBig()){
SuperMario.manager.get("audio/breakblock.wav", Sound.class).play();
setCategoryFilter(SuperMario.DESTROYED_BIT);
getCell().setTile(null);
}
else {
SuperMario.manager.get("audio/bump.wav", Sound.class).play();
// DOES THE EXACT SAME AS LATER 3 LINES
// getCell().getTile().setOffsetY(2);
getCell().setTile(tileSet.getTile(28)); //this can change texture of individual tile.
TiledMapTile tile = getCell().getTile();
tile.setOffsetY(2);
getCell().setTile(tile);
}
}
}
InteractiveTile:
public abstract class InteractiveTile {
private World world;
private TiledMap map;
private TiledMapTile tile;
private Rectangle bounds;
protected Body body;
protected final Fixture fixture;
protected PlayScreen screen;
protected MapObject object;
public InteractiveTile(PlayScreen screen, MapObject object){
this.screen = screen;
this.world = screen.getWorld();
this.map = screen.getMap();
this.object = object;
this.bounds = ((RectangleMapObject)object).getRectangle();
BodyDef bdef = new BodyDef();
FixtureDef fdef = new FixtureDef();
PolygonShape shape = new PolygonShape();
bdef.type = BodyDef.BodyType.StaticBody;
bdef.position.set(
(bounds.getX()+ bounds.getWidth()/2)/ SuperMario.PPM,
(bounds.getY() + bounds.getHeight()/2)/SuperMario.PPM);
body = world.createBody(bdef);
shape.setAsBox(
(bounds.getWidth()/2)/SuperMario.PPM,
(bounds.getHeight()/2)/SuperMario.PPM); fdef.shape = shape;
fixture = body.createFixture(fdef);
}
public abstract void onHeadHit(Mario mario);
public TiledMapTileLayer.Cell getCell(){
TiledMapTileLayer layer = (TiledMapTileLayer) map.getLayers().get(1);
return layer.getCell(
//REVERT SCALING (PPM) AND by tile size
(int)(body.getPosition().x * SuperMario.PPM / 16),
(int)(body.getPosition().y * SuperMario.PPM / 16));
}
public void setCategoryFilter(short filterBit){
Filter filter = new Filter();
filter.categoryBits = filterBit;
fixture.setFilterData(filter);
}
}
is there an error in this code, or it is a limitation of the engine?
PS - the original (unmodified)files can be found on Brent Aurelis github site:
https://github.com/BrentAureli/SuperMario

JMonkey Endless Terrain Example: How to change the render distance

The Jmoneky Engine gives example code for endless randomly generated Terrain. My Problem is, the code has no comments or indicators to edit the View distance. I am trying to use this example code to build a game, but it looks really bad if the render distance is so short you can see the bottom of the world(void)
The Code:
public class TerrainFractalGridTest extends SimpleApplication {
private Material mat_terrain;
private TerrainGrid terrain;
private float grassScale = 64;
private float dirtScale = 16;
private float rockScale = 128;
public static void main(final String[] args) {
TerrainFractalGridTest app = new TerrainFractalGridTest();
app.start();
}
private CharacterControl player3;
private FractalSum base;
private PerturbFilter perturb;
private OptimizedErode therm;
private SmoothFilter smooth;
private IterativeFilter iterate;
#Override
public void simpleInitApp() {
this.flyCam.setMoveSpeed(100f);
ScreenshotAppState state = new ScreenshotAppState();
this.stateManager.attach(state);
// TERRAIN TEXTURE material
this.mat_terrain = new Material(this.assetManager, "Common/MatDefs/Terrain/HeightBasedTerrain.j3md");
// Parameters to material:
// regionXColorMap: X = 1..4 the texture that should be appliad to state X
// regionX: a Vector3f containing the following information:
// regionX.x: the start height of the region
// regionX.y: the end height of the region
// regionX.z: the texture scale for the region
// it might not be the most elegant way for storing these 3 values, but it packs the data nicely :)
// slopeColorMap: the texture to be used for cliffs, and steep mountain sites
// slopeTileFactor: the texture scale for slopes
// terrainSize: the total size of the terrain (used for scaling the texture)
// GRASS texture
Texture grass = this.assetManager.loadTexture("Textures/Terrain/splat/grass.jpg");
grass.setWrap(WrapMode.Repeat);
this.mat_terrain.setTexture("region1ColorMap", grass);
this.mat_terrain.setVector3("region1", new Vector3f(15, 200, this.grassScale));
// DIRT texture
Texture dirt = this.assetManager.loadTexture("Textures/Terrain/splat/dirt.jpg");
dirt.setWrap(WrapMode.Repeat);
this.mat_terrain.setTexture("region2ColorMap", dirt);
this.mat_terrain.setVector3("region2", new Vector3f(0, 20, this.dirtScale));
// ROCK texture
Texture rock = this.assetManager.loadTexture("Textures/Terrain/Rock2/rock.jpg");
rock.setWrap(WrapMode.Repeat);
this.mat_terrain.setTexture("region3ColorMap", rock);
this.mat_terrain.setVector3("region3", new Vector3f(198, 260, this.rockScale));
this.mat_terrain.setTexture("region4ColorMap", rock);
this.mat_terrain.setVector3("region4", new Vector3f(198, 260, this.rockScale));
this.mat_terrain.setTexture("slopeColorMap", rock);
this.mat_terrain.setFloat("slopeTileFactor", 32);
this.mat_terrain.setFloat("terrainSize", 513);
this.base = new FractalSum();
this.base.setRoughness(0.7f);
this.base.setFrequency(1.0f);
this.base.setAmplitude(1.0f);
this.base.setLacunarity(2.12f);
this.base.setOctaves(8);
this.base.setScale(0.02125f);
this.base.addModulator(new NoiseModulator() {
#Override
public float value(float... in) {
return ShaderUtils.clamp(in[0] * 0.5f + 0.5f, 0, 1);
}
});
FilteredBasis ground = new FilteredBasis(this.base);
this.perturb = new PerturbFilter();
this.perturb.setMagnitude(0.119f);
this.therm = new OptimizedErode();
this.therm.setRadius(5);
this.therm.setTalus(0.011f);
this.smooth = new SmoothFilter();
this.smooth.setRadius(1);
this.smooth.setEffect(0.7f);
this.iterate = new IterativeFilter();
this.iterate.addPreFilter(this.perturb);
this.iterate.addPostFilter(this.smooth);
this.iterate.setFilter(this.therm);
this.iterate.setIterations(1);
ground.addPreFilter(this.iterate);
this.terrain = new TerrainGrid("terrain", 33, 129, new FractalTileLoader(ground, 256f));
this.terrain.setMaterial(this.mat_terrain);
this.terrain.setLocalTranslation(0, 0, 0);
this.terrain.setLocalScale(2f, 1f, 2f);
this.rootNode.attachChild(this.terrain);
TerrainLodControl control = new TerrainGridLodControl(this.terrain, this.getCamera());
control.setLodCalculator(new DistanceLodCalculator(33, 2.7f)); // patch size, and a multiplier
this.terrain.addControl(control);
this.getCamera().setLocation(new Vector3f(0, 300, 0));
this.viewPort.setBackgroundColor(new ColorRGBA(0.7f, 0.8f, 1f, 1f));
}
#Override
public void simpleUpdate(final float tpf) {
}}
So following what J Atkin said about Terrain Grid, I found a endless terrain example that is a terrain grid. The Cells loaded class is protected, which means I have to extends it in the class to access it. In Jmonkey, the main class has to extend a simple application in order to run. Java doesn't allow multiple extensions, therefor I build a second class to allow access.
public class ViewTerrain extends TerrainGrid{
public void setView(int numberofcells){
super.cellsLoaded = numberofcells;
}
}
problem I am having with this class is that I don't know how to keep the original declaration IE.
this.terrain = new TerrainGrid("terrain", 65, 257, new ImageTileLoader(assetManager, new Namer() {
public String getName(int x, int y) {
return "Scenes/TerrainMountains/terrain_" + x + "_" + y + ".png";
}
}));
Looking at the source it seems TerrainGrid dynamically redefines an internal TerrainQuad tree based upon which grid the camera is in and the surrounding grid tiles. It would seem to me that you should define these tiles to be the size of the area you would like visible at any one time. Try updating patchSize in the constructor to be larger.

jmonkeyengine movement too fast for collision detection

I am making a Java game using JMonkeyEngine and I have followed the tutorial on their site to shoot balls (bullets) at a wall. I get how everything works, but when I increase the velocity of the bullet, it passes straight through the wall.
Now I know the reason why this is happening (because the bullet moves too fast per frame for collision to register). I also know how to solve for this and I have found the following method on their website (JMonkeyEngine).
setCcdMotionThreshold(0f)
But can anyone tell me how this is implemented or where I can find a sample of someone using this?
Introduction
Continuous collision detection (ccd) deals with the bullet vs paper problem. Where a fast moving object is one side of a thin object at one timestep and the other side at the next time step leading to the physics engine believing that no collision has occurred at all. Continuous collision detection on the other hand doesn't use time steps at all. It creates a swept volume over the entire period of the timestep and finds if that swept volume collides with anything. This is both expensive and inaccurate (because a simple circular collision shape is used for this rather than the full collision shape).
Usage
Continuous collision detection is set on a per object basic, you can have objects that use ccd and objects that don't in the same scene at the same time, ccd is set on a physics object as shown below
RigidBodyControl physicsObject = new RigidBodyControl(mass);
physicsObject.setCcdMotionThreshold(expectedWidthOfThinObject);
physicsObject.setCcdSweptSphereRadius(radiusOfSphereThatWillFullyContainObject);
You want to set expectedWidthOfThinObject as high you can get away
with; remember ccd is expensive and inaccurate. Setting it as zero will turn ccd off
You want to set radiusOfSphereThatWillFullyContainObject as small as possible while fully containing the object
Full example
The following source code will show the difference between using Continuous Collision Detection and using the standard collision detection. It fires two sets of balls, one fast and one slow and turns ccd on and off at 5 second intervals. The slow balls always collide with the paper, the fast ones only when ccd is turned on.
import com.jme3.app.SimpleApplication;
import com.jme3.bullet.BulletAppState;
import com.jme3.bullet.control.RigidBodyControl;
import com.jme3.font.BitmapText;
import com.jme3.material.Material;
import com.jme3.math.ColorRGBA;
import com.jme3.math.Vector3f;
import com.jme3.scene.Geometry;
import com.jme3.scene.shape.Box;
import com.jme3.scene.shape.Sphere;
public class BulletTest extends SimpleApplication {
public static void main(String args[]) {
BulletTest app = new BulletTest();
app.start();
}
/** Prepare the Physics Application State (jBullet) */
private BulletAppState bulletAppState;
/** Prepare Materials */
Material wall_mat;
Material slow_mat;
Material fast_mat;
Material floor_mat;
private RigidBodyControl brick_phy;
private static final Box box;
private static final Sphere sphere;
private RigidBodyControl floor_phy;
private static final Box floor;
/** dimensions used for wall */
private static final float brickLength = 2f;
private static final float brickWidth = 0.015f;
private static final float brickHeight = 1f;
static {
/** Initialize the cannon ball geometry */
sphere = new Sphere(32, 32, 0.1f, true, false);
/** Initialize the brick geometry */
box = new Box(brickWidth, brickHeight, brickLength);
/** Initialize the floor geometry */
floor = new Box(10f, 0.1f, 5f);
}
#Override
public void simpleInitApp() {
/** Set up Physics Game */
bulletAppState = new BulletAppState();
stateManager.attach(bulletAppState);
//bulletAppState.getPhysicsSpace().enableDebug(assetManager);
/** Configure cam to look at scene */
cam.setLocation(new Vector3f(0, 4f, 6f));
cam.lookAt(new Vector3f(2, 2, 0), Vector3f.UNIT_Y);
/** Initialize the scene, materials, and physics space */
initMaterials();
initWall();
initFloor();
setUpHUDText();
}
public static final float FIREPERIOD=0.5f;
double fireTimer=0;
public static final float SWEEPPERIOD=5f;
double sweepTimer=0;
boolean continuouslySweeping=true;
#Override
public void simpleUpdate(float tpf) {
fireTimer+=tpf;
sweepTimer+=tpf;
if (sweepTimer>SWEEPPERIOD){
sweepTimer=0;
continuouslySweeping=!continuouslySweeping;
}
hudText.setText("ContinouslySweeping=" + continuouslySweeping + "(" + (int)(SWEEPPERIOD-sweepTimer) + ")" );
if (fireTimer>FIREPERIOD){
fireTimer=0;
makeCannonBall(new Vector3f(-4,3,0),new Vector3f(6,4,0),slow_mat,continuouslySweeping); //slow arcing ball
makeCannonBall(new Vector3f(-4,3,-0.5f),new Vector3f(10,1,0),fast_mat,continuouslySweeping); //fast straight ball
}
}
public BitmapText hudText;
private void setUpHUDText(){
hudText = new BitmapText(guiFont, false);
hudText.setSize(guiFont.getCharSet().getRenderedSize()); // font size
hudText.setColor(ColorRGBA.White); // font color
hudText.setText("ContinouslySweeping=true"); // the text
hudText.setLocalTranslation(300, hudText.getLineHeight(), 0); // position
guiNode.attachChild(hudText);
}
/** Initialize the materials used in this scene. */
public void initMaterials() {
wall_mat = new Material(assetManager, "Common/MatDefs/Misc/Unshaded.j3md");
wall_mat.setColor("Color", ColorRGBA.Blue);
fast_mat = new Material(assetManager, "Common/MatDefs/Misc/Unshaded.j3md");
fast_mat.setColor("Color", ColorRGBA.Red);
slow_mat = new Material(assetManager, "Common/MatDefs/Misc/Unshaded.j3md");
slow_mat.setColor("Color", ColorRGBA.Green);
floor_mat = new Material(assetManager, "Common/MatDefs/Misc/Unshaded.j3md");
floor_mat.setColor("Color", ColorRGBA.Gray);
}
/** Make a solid floor and add it to the scene. */
public void initFloor() {
Geometry floor_geo = new Geometry("Floor", floor);
floor_geo.setMaterial(floor_mat);
floor_geo.setLocalTranslation(0, -0.1f, 0);
this.rootNode.attachChild(floor_geo);
/* Make the floor physical with mass 0.0f! */
floor_phy = new RigidBodyControl(0.0f);
floor_geo.addControl(floor_phy);
bulletAppState.getPhysicsSpace().add(floor_phy);
}
/** This loop builds a wall out of individual bricks. */
public void initWall() {
Vector3f location=new Vector3f(2,2,0);
Geometry brick_geo = new Geometry("brick", box);
brick_geo.setMaterial(wall_mat);
rootNode.attachChild(brick_geo);
/** Position the brick geometry */
brick_geo.setLocalTranslation(location);
//paper thin objects will fall down, mass 0 clamps it in position
brick_phy = new RigidBodyControl(0);
/** Add physical brick to physics space. */
brick_geo.addControl(brick_phy);
bulletAppState.getPhysicsSpace().add(brick_phy);
}
public void makeCannonBall(Vector3f startPoint, Vector3f initialVelocity, Material material, boolean continuouslySwept) {
/** Create a cannon ball geometry and attach to scene graph. */
Geometry ball_geo = new Geometry("cannon ball", sphere);
ball_geo.setMaterial(material);
rootNode.attachChild(ball_geo);
/** Position the cannon ball */
ball_geo.setLocalTranslation(startPoint);
/** Make the ball physcial with a mass > 0.0f */
RigidBodyControl ball_phy = new RigidBodyControl(1f);
/** Add physical ball to physics space. */
ball_geo.addControl(ball_phy);
bulletAppState.getPhysicsSpace().add(ball_phy);
/** Accelerate the physcial ball to shoot it. */
ball_phy.setLinearVelocity(initialVelocity);
if (continuouslySwept){
ball_phy.setCcdMotionThreshold(0.015f);
ball_phy.setCcdSweptSphereRadius(0.01f);
}
}
}
With continuous detection on both sets of balls bounce of as expected (balls entering from the top left):
With continuous detection off the fast set of balls (red) passes through the paper as if it wasn't there (and very occasionally a slow one (green) does too):
NB: this code is loosely based on the hello physics code with added functionality from advanced physics

How can I get the coordinates of a point in 3D based on a mouse click?

I want that when I click on a specific point on the screen, a function call that return the point in 3d scene that I click.
For example, when I click on the top left of the screen, it should return x = 0, y = 1, z= 1; please help me create a method to do this.
edit:
Root = new BranchGroup();
setLayout(new BorderLayout());
add(canvas3D,BorderLayout.CENTER);
SimpleUniverse universe = new SimpleUniverse(canvas3D);
Shape();
universe.addBranchGraph(Root);
ViewingPlatform viewingPlatform = universe.getViewingPlatform();
OrbitBehavior behavior = new OrbitBehavior(canvas3D);
behavior.setSchedulingBounds(bounds);
viewingPlatform.setViewPlatformBehavior(behavior);
viewingPlatform.setNominalViewingTransform();
}
I'm using SimpleUniverse in NetBeans.
I'm afraid the answer isn't straight forward. Depending on what is in your scene the mouse coordinates should change when you click on the screen. For instance if you have two objects so that the front one occludes the back one then you'd want to get the front objects coordinates. This is called mouse picking and there are several techniques for it. I found a few forums that explain how it's done and have code examples.
Basically the idea is that you imagine there being a laser (or something else that casts a ray) between you the user and the screen. This thing then projects a ray through the point on the screen surface where the mouse was clicked "into" the screen. Anything that is on the rays path will then be picked and optionally the occlusion order of objects in the ray's path is resolved to give you the object closest to the "screen".
I am not familiar with J3D, but scraped the following code together from a few tutorials. It should get you started at least. The this you are looking for is this line Point3D intercept = ... at the bottom.
http://www.java3d.org/selection.html
package j3d_picking;
import java.awt.*;
import javax.swing.*;
import javax.media.j3d.*;
import com.sun.j3d.utils.universe.*;
import com.sun.j3d.utils.picking.behaviors.*;
import com.sun.j3d.utils.geometry.*;
import com.sun.j3d.utils.picking.PickIntersection;
import com.sun.j3d.utils.picking.PickResult;
import com.sun.j3d.utils.picking.PickTool;
import javax.vecmath.Point3d;
public class HelloJava3D
extends JFrame
{
public HelloJava3D()
{
GraphicsConfiguration config = SimpleUniverse.getPreferredConfiguration();
Canvas3D canvas3D = new Canvas3D(config);
BranchGroup scene = createSceneGraph();
// SimpleUniverse is a Convenience Utility class
SimpleUniverse simpleU = new SimpleUniverse(canvas3D);
// This moves the ViewPlatform back a bit so the
// objects in the scene can be viewed.
simpleU.getViewingPlatform().setNominalViewingTransform();
BoundingSphere behaveBounds = new BoundingSphere();
ExamplePickBehavior behavior = new ExamplePickBehavior(canvas3D, scene, behaveBounds);
scene.addChild(behavior);
scene.compile();
simpleU.addBranchGraph(scene);
getContentPane().add(canvas3D, BorderLayout.CENTER);
} // end of HelloJava3D (constructor)
public BranchGroup createSceneGraph()
{
// Create the root of the branch graph
BranchGroup objRoot = new BranchGroup();
// Create a simple shape leaf node, add it to the scene graph.
// ColorCube is a Convenience Utility class
ColorCube cube = new ColorCube(0.4);
cube.setCapability(Node.ENABLE_PICK_REPORTING);
PickTool.setCapabilities(cube, PickTool.INTERSECT_FULL);
objRoot.addChild(cube);
return objRoot;
} // end of createSceneGraph method of HelloJava3D
public static void main(String[] args)
{
JFrame frame = new HelloJava3D();
frame.setTitle("Hello Java3D");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setBounds(0, 0, 400, 300);
frame.setVisible(true);
}
private class ExamplePickBehavior extends PickMouseBehavior
{
public ExamplePickBehavior(Canvas3D canvas, BranchGroup bg, Bounds bounds)
{
super(canvas, bg, bounds);
setSchedulingBounds(bounds);
pickCanvas.setMode(PickTool.GEOMETRY_INTERSECT_INFO);
// allows PickIntersection objects to be returned
}
public void updateScene(int xpos, int ypos)
{
pickCanvas.setShapeLocation(xpos, ypos);
// register mouse pointer location on the screen (canvas)
Point3d eyePos = pickCanvas.getStartPosition();
// get the viewer's eye location
PickResult pickResult = null;
pickResult = pickCanvas.pickClosest();
// get the intersected shape closest to the viewer
if (pickResult != null) {
PickIntersection pi = pickResult.getClosestIntersection(eyePos);
// get the closest intersect to the eyePos point
Point3d intercept = pi.getPointCoordinatesVW();
System.out.println(intercept);
// extract the intersection pt in scene coords space
// use the intersection pt in some way...
}
} // end of updateScene( )
} // end of ExamplePickBehavior class
}
enter code hereThe Java code below , prints the 3d object's (shapes) center coordinates in the 3d screen. Result is (x=-0.5 ,y=0.0 ,z=0.4)
public class secim2 extends MouseAdapter{
private PickCanvas pickCanvas;
public secim2(){
JFrame pencere=new JFrame();
pencere.setSize(300, 300);
pencere.setVisible(true);
JFrame frame = new JFrame(" 3D Box Select");
GraphicsConfiguration config = SimpleUniverse.getPreferredConfiguration();
Canvas3D canvas = new Canvas3D(config);
SimpleUniverse universe = new SimpleUniverse(canvas);
BranchGroup group = new BranchGroup();
// create a color cube
Transform3D transform= new Transform3D();
Vector3d vector = new Vector3d(-0.5, 0.0, 0.4);
Transform3D transform = new Transform3D();
transform.setTranslation(vector);
TransformGroup transformGroup = new TransformGroup(transform);
ColorCube cube = new ColorCube(0.1f);
transformGroup.addChild(cube);
group.addChild(transformGroup);
universe.getViewingPlatform().setNominalViewingTransform();
universe.addBranchGraph(group);
pickCanvas = new PickCanvas(canvas, group);
pickCanvas.setMode(PickCanvas.GEOMETRY_INTERSECT_INFO);
pencere.add(canvas);
canvas.addMouseListener(this);
}
public void mouseClicked(MouseEvent e)
{
pickCanvas.setShapeLocation(e);
PickResult result = pickCanvas.pickClosest();
if (result == null) {
} else {
Primitive p = (Primitive)result.getNode(PickResult.PRIMITIVE);
Shape3D s = (Shape3D)result.getNode(PickResult.SHAPE3D);
if (p != null) {
System.out.println(p.getClass().getName());
} else if (s != null) {
System.out.println(s.getClass().getName());
Vector3f position = new Vector3f();
s.getLocalToVworld(transform);
transform.get(position);
System.out.print(position);
// System.out.print( s.getLocalToVworld(transform2);
} else{
System.out.println("null");
}
}
}
}
public class tuval1 {
public static void main(String[] args) {
// TODO Auto-generated method stub
new secim2();
}
}

GLSurfaceView swaps 2D bitmaps being drawn

I have an application that receives information from a database, and is used to visualize 2D bitmaps onto a GLSurfaceView. The information received will determine the x-position of the bitmap, and which bitmap image to use (there are 4 different bitmaps in my res folder to choose from).
Below are the three classes that are being used. The Activity sets the Shapes objects that need to be drawn by passing an ArrayList to the GLLayer class. This ArrayList is passed to the instance of ShapeStorage class via another setList method. This class is responsible for drawing when they are received.
The problem that I'm having is the following. Suppose I receive one object (let's say that it's a square at it's located at x=1). Some time goes by, and I receive another shape (this time, it's a triangle, and it's located at x=-1). However, when this new shape appears on the screen, the old bitmap's appearance changes to a triangle, and the new one becomes a square. In other words, the objects themselves are at the correct position that they are supposed to be at, but the bitmap being associated with them has changed. Does anyone know what the possible cause of this can be? I'm still a newbie to OpenGL-ES, and while this code looks very convoluted, it just involves setting a bunch of various properties for the View. Please help me, StackOverflow! You're my only hope.
public class GLLayer extends GLSurfaceView implements Renderer {
int onDrawFrameCounter=1;
int[] cameraTexture;
byte[] glCameraFrame=new byte[256*256]; //size of a texture must be a power of 2
private Context context;
FloatBuffer cubeBuff;
FloatBuffer texBuff;
ShapeStorage shapes;
ArrayList<Shapes> shapereceptionbuffer;
public GLLayer(Context c) {
super(c);
this.context=c;
//Initiate our stars class with the number of stars
shapes = new ShapeStorage();
shapereceptionbuffer=new ArrayList<Shapes>();
this.setEGLConfigChooser(5, 6, 5, 8, 16, 0);
this.setRenderer(this); //set the following class as a GLSurfaceView renderer
this.getHolder().setFormat(PixelFormat.TRANSPARENT); //makes the GLSurfaceView translucent
}
public void onSurfaceCreated(GL10 gl, EGLConfig config) {
try {
gl.glHint(GL10.GL_PERSPECTIVE_CORRECTION_HINT, GL10.GL_FASTEST);
gl.glShadeModel(GL10.GL_SMOOTH); //Enable Smooth Shading
gl.glEnable(GL10.GL_TEXTURE_2D); //Enable Texture Mapping
gl.glEnable(GL10.GL_BLEND); //Enable blending
gl.glClearColor(0.0f, 0.0f, 0.0f, 0.0f); //Black Background
gl.glClearDepthf(1.0f); //Depth Buffer Setup
gl.glDisable(GL10.GL_DEPTH_TEST); //Disable depth test
gl.glBlendFunc(GL10.GL_SRC_ALPHA, GL10.GL_ONE); //Set The Blending Function For Translucency
shapes.setTextures(gl,context);
} catch (Exception e) {
// TODO Auto-generated catch block
Log.d("Created",e.getMessage());
}
}//end of surfacecreated
public void setList(ArrayList<Shapes> receivedList){
synchronized(this.shapereceptionbuffer){
shapereceptionbuffer=receivedList;
}
}
public void onSurfaceChanged(GL10 gl, int width, int height) {
try {
if(height == 0) { //Prevent A Divide By Zero By
height = 1; //Making Height Equal One
}
gl.glViewport(0, 0, width, height);//specifies transformation from normalized device coordinates to window coordinates
float ratio = (float) width / height;
gl.glMatrixMode(GL11.GL_PROJECTION); //Select The Projection Matrix
gl.glLoadIdentity();//Reset The Projection Matrix
GLU.gluPerspective(gl, 45.0f, ratio, 0.1f, 100.0f);
gl.glMatrixMode(GL11.GL_MODELVIEW);//Select The Modelview Matrix
gl.glLoadIdentity();//Reset The Modelview Matrix
} catch (Exception e) {
// TODO Auto-generated catch block
Log.d("Changed",e.getMessage());
}
//GLU.gluLookAt(gl, 0, 0, 4.2f, 0, 0, 0, 0, 1, 0);//eye-point location, center of the scene and an UP vector
}//end of surfacechanged
public void onDrawFrame(GL10 gl) {
try {
gl.glClear(GL10.GL_COLOR_BUFFER_BIT | GL10.GL_DEPTH_BUFFER_BIT); //Clear Screen And Depth Buffer
Log.d("Buffer Size", String.valueOf(shapereceptionbuffer.size()));
synchronized(this.shapereceptionbuffer){
shapes.setShapes(shapereceptionbuffer);
shapes.draw(gl, this.context);
}
} catch (Exception e) {
Log.d("Draw",e.getMessage());
}
}//end of ondrawframe
}
This class is responsible for drawing each of the shapes that are received from the external database.
/**
* This class contains, loads, initiates textures and draws our Shapes
*/
public class ShapeStorage {
private ArrayList<Shapes> shapestoragebuffer;
private Random rand = new Random(); // Initiate Random for random values of
// stars
/** Our texture pointer */
private int[] textures = new int[4];
/**
* Constructor for our holder
*/
public ShapeStorage() {
shapestoragebuffer = new ArrayList<Shapes>();
}
public void setShapes(ArrayList<Shapes> receivedlist) {
shapestoragebuffer = receivedList;
}
public void setupTextures(GL10 gl, Context context) {
// Get the texture from the Android resource directory
InputStream is = null;
gl.glGenTextures(4, textures, 0);
for (int i = 2; i < 6; i++) {
switch (i) {
case 2:
is = context.getResources().openRawResource(R.drawable.square);
break;
case 3:
is = context.getResources().openRawResource(R.drawable.circle);
break;
case 4:
is = context.getResources().openRawResource(R.drawable.hexagon);
break;
case 5:
is = context.getResources()
.openRawResource(R.drawable.triangle);
break;
}
Bitmap bitmap = null;
try {
// BitmapFactory is an Android graphics utility for images
bitmap = BitmapFactory.decodeStream(is);
} finally {
// Always clear and close
try {
is.close();
is = null;
} catch (IOException e) {
}
}
// Generate the texture pointer
// Create Linear Filtered Texture and bind it to texture
GLUtils.texImage2D(GL11.GL_TEXTURE_2D, 0, bitmap, 0);
gl.glBindTexture(GL11.GL_TEXTURE_2D, textures[i - 2]);
gl.glTexParameterf(GL11.GL_TEXTURE_2D, GL11.GL_TEXTURE_MAG_FILTER,
GL11.GL_LINEAR);
gl.glTexParameterf(GL11.GL_TEXTURE_2D, GL11.GL_TEXTURE_MIN_FILTER,
GL11.GL_LINEAR);
// Clean up
bitmap.recycle();
}
}
/**
* The drawing function.
*
* #param gl
* - The GL Context
* #param twinkle
* - Twinkle on or off
*/
public void draw(GL10 gl, Context context) {
// Bind the icon texture for all Shapes
for (int loop = 0; loop < shapestoragebuffer.size(); loop++) {
// Recover the current star into an object
Shapes shape = shapestoragebuffer.get(loop);
gl.glLoadIdentity(); // Reset The Current Modelview Matrix
// gl.glRotatef(180.0f, -1.0f, 0.0f, 0.0f);
float x = shape.get_Offset_from_center();
gl.glTranslatef(x, 0.0f, -40.0f);
// Draw
switch (victim.getType()) {
// green
case 2:
shape.draw(gl, textures[0]);
break;
// red
case 3:
shape.draw(gl, textures[1]);
break;
// yellow
case 4:
shape.draw(gl, textures[2]);
break;
case 5:
shape.draw(gl, textures[3]);
break;
}
}
}
}
Here is the class that defines each of the objects that are being drawn to the GLSurfaceView; each of the shapes that are being drawn.
public class Shapes {
private int _Offset_from_center;
private int type;
Context c;
/** The buffer holding the vertices */
private FloatBuffer vertexBuffer;
/** The buffer holding the texture coordinates */
private FloatBuffer textureBuffer;
/** The initial vertex definition */
private float vertices[] = {
-1.0f, -1.0f, 0.0f, //Bottom Left
1.0f, -1.0f, 0.0f, //Bottom Right
-1.0f, 1.0f, 0.0f, //Top Left
1.0f, 1.0f, 0.0f //Top Right
};
/** The initial texture coordinates (u, v) */
private float texture[] = {
0.0f, 0.0f,
1.0f, 0.0f,
0.0f, 1.0f,
1.0f, 1.0f,
};
public Shapes() {
//
ByteBuffer byteBuf = ByteBuffer.allocateDirect(vertices.length * 4);
byteBuf.order(ByteOrder.nativeOrder());
vertexBuffer = byteBuf.asFloatBuffer();
vertexBuffer.put(vertices);
vertexBuffer.position(0);
//
byteBuf = ByteBuffer.allocateDirect(texture.length * 4);
byteBuf.order(ByteOrder.nativeOrder());
textureBuffer = byteBuf.asFloatBuffer();
textureBuffer.put(texture);
textureBuffer.position(0);
}
public int get_Offset_from_center() {
return _Offset_from_center;
}
public void set_Offset_from_center(int _Offset_from_center) {
this._Offset_from_center = _Offset_from_center;
}
public int getType() {
return type;
}
public void setType(int type) {
this.type = type;
}
/**
* The object own drawing function.
* Called from the renderer to redraw this instance
* with possible changes in values.
*
* #param gl - The GL Context
*/
public void draw(GL10 gl,int texture) {
gl.glBindTexture(GL11.GL_TEXTURE_2D, texture);
//Enable the vertex, texture and normal state
gl.glEnableClientState(GL11.GL_VERTEX_ARRAY);
gl.glEnableClientState(GL11.GL_TEXTURE_COORD_ARRAY);
//Point to our buffers
gl.glVertexPointer(3, GL11.GL_FLOAT, 0, vertexBuffer);
gl.glTexCoordPointer(2, GL11.GL_FLOAT, 0, textureBuffer);
//Draw the vertices as triangle strip
gl.glDrawArrays(GL11.GL_TRIANGLE_STRIP, 0, vertices.length / 3);
//Disable the client state before leaving
gl.glDisableClientState(GL11.GL_VERTEX_ARRAY);
gl.glDisableClientState(GL11.GL_TEXTURE_COORD_ARRAY);
}
}
You're doing something very strange with the textures. Why do you upload the texture image data for every shape on every frame, and why do you do it after you render the shape?
Here's how the usual flow of texture use in OpenGL works:
At app initialization time:
Generate a texture ID using glGenTextures.
Use glBindTexture to make that ID the current texture.
Set texture parameters.
Upload image data with texImage2D or similar.
Then, every time you need to render stuff with the texture:
Bind the texture with glBindTexture with the same ID you used above.
Render things, which will use the texture.
What I would recommend here is this:
When you activity starts up (called indirectly from onCreate or maybe onResume depending on how Android OpenGL works):
Make textures a 5-element array and pass 5 to glGenTextures
Loop through, and for each of your five resources, bind one of the four above, and upload your image with texImage2D just like you have.
Then, when you actually need to draw a shape:
Pass in an int for the texture, not an int[]; choose the right one based on the shape you want.
Call glBindTexture in your draw function, first, with that value.
Do not make any calls to texImage2D in your rendering pass.
Call glDrawArrays to draw the shape you chose with glBindTexture.
Note also that all your shapes can share the same vertex and texture buffers, since their contents are the same; that's just an efficiency thing though.

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