In netbeans, there is an option under samples called CubeSystem3D. I was wondering if there was a way to convert all of the cubes to spheres so I can eventually create a solar system type of thing. I can send the actual code if you are unable to retrieve it off netbeans because I can not put the code of this post as it says there will be too much code compared with text.
Use below Ellipse class instead of Cube class in that neabeans sample code.
public class Ellipse extends Group {
final Rotate rx = new Rotate(0, Rotate.X_AXIS);
final Rotate ry = new Rotate(0, Rotate.Y_AXIS);
final Rotate rz = new Rotate(0, Rotate.Z_AXIS);
public Ellipse(double size, Color color, double shade) {
PhongMaterial material = new PhongMaterial();
material.setDiffuseColor(color);
material.setSpecularColor(Color.BLACK);
getTransforms().addAll(rz, ry, rx);
Sphere s = new Sphere(size);
s.setMaterial(material);
getChildren().addAll(s);
}
}
You will get something like this,
Related
I'm trying to add a 2D overlay for a 3D scene in Java3D, part of this overlay is to draw a line from a 2D object to a corresponding point in the 3D scene...
Searched transformation from 3D to 2D and read those threads:
Translate Java 3D coordinates to 2D screen coordinates
3D to 2D projection
from code inside walrus:
https://github.com/CAIDA/walrus/blob/master/H3ViewParameters.java
copied a method to a class extending Canvas3D:
public Transform3D getObjectToEyeTransform() {
Point3d m_eye = new Point3d();
getCenterEyeInImagePlate(m_eye);
Transform3D m_imageToEye = new Transform3D();
m_imageToEye.set(new Vector3d(-m_eye.x, -m_eye.y, 0.0));
Transform3D m_vworldToImage = new Transform3D();
getVworldToImagePlate(m_vworldToImage);
Transform3D transform = new Transform3D(m_imageToEye);
transform.mul(m_vworldToImage);
//transform.mul(m_objectTransform);
return transform;
}
and then in my overlay in method postRender i try to do the following:
Transform3D viewTrans3d = getObjectToEyeTransform();
Vector3d point = new Vector3d(1,1,1);
viewTrans3d.invert();
viewTrans3d.transform(point);
this.getGraphics2D().drawLine(0, 0, (int)point.x, (int)point.y);
Getting very weird line, which do change in a quite logical pattern (when i rotate and tilt the view) but far from what i expect...
Questions:
commented the m_objectTransform matrix multiplication because i
don't understand its purpose, any idea?
Why do i need to invert the transform matrix? without the invert the results are even weirder...
Is there a simpler way to do this??? sounds like something solved eons ago...
This can be done by using getVworldToImagePlate and then getPixelLocationFromImagePlate in the Canvas3D class. For example:
public Point2d getPosition2d(Point3d point) {
Transform3D transform = new Transform3D();
getVworldToImagePlate(transform);
transform.mul(objectTransform);
Point3d newPoint = new Point3d(point);
transform.transform(newPoint);
Point2d point2d = new Point2d();
getPixelLocationFromImagePlate(newPoint, point2d);
return point2d;
}
The objectTransform variable should be the transform of any TransformGroup in the scene that is applied to the 3d objects that are displayed. If you don't have any TransformGroup, then you can leave this out. Also, the transform shouldn't be inverted, just use it as it is.
I'm using LibGDX with Scene2D for my java game. I know my issue is connected to Scene2D, because I used the EXACT same class passing it normally to SpriteBatch (not through Stage instance) and it worked as expected.
I let Stage manage all of my drawables entities which are actors. It draws everything using implementor of Batch; SpriteBatch is the default. And it was working until I wanted to draw a polygon, which has to be drawn by PolygonSpriteBatch, not SpriteBatch.. So during one Stage.draw() call I need to use them both.
I made a CheckedPolygon class which is basically two PolygonSprites drawn on top of each other (one is semi-transparent). SpriteBatch passed in draw() method is temporarily ended to enable PolygonSpriteBatch for a moment, draw the polygon and disable it.
And the output is empty screen, I get nothing. Again, it worked when I wasn't using Stage class.
Here's the class, so you get a better understanding.
NOTE: I know this is bad in terms of performance, because I don't dispose of Texture and keep Batch for one object but it's for the sake of simplicity.
NOTE2: Yes, I passed it properly to stage, the code is executed, I checked through debugging.
public class CheckedPolygon extends Actor {
private final PolygonSprite mBackground, mCross;
private final PolygonSpriteBatch mPolygonSpriteBatch;
private final Camera mCamera;
public CheckedPolygon(Camera camera, float[] vertices, short[] triangles) {
super();
mCamera = camera;
mPolygonSpriteBatch = new PolygonSpriteBatch();
Texture textureBack = new Texture(Gdx.files.internal("source/back.png"));
textureBack.setWrap(Texture.TextureWrap.Repeat, Texture.TextureWrap.Repeat);
PolygonRegion regionBack = new PolygonRegion(new TextureRegion(textureBack), vertices, triangles);
mBackground = new PolygonSprite(regionBack);
Texture textureCross = new Texture(Gdx.files.internal("source/cross.png"));
textureCross.setWrap(Texture.TextureWrap.Repeat, Texture.TextureWrap.Repeat);
PolygonRegion regionCross = new PolygonRegion(new TextureRegion(textureCross), vertices, triangles);
mCross = new PolygonSprite(regionCross);
}
#Override
public void draw(Batch batch, float parentAlpha) {
batch.end();
mPolygonSpriteBatch.setProjectionMatrix(mCamera.combined);
mPolygonSpriteBatch.begin();
mBackground.draw(mPolygonSpriteBatch);
mCross.draw(mPolygonSpriteBatch);
mPolygonSpriteBatch.end();
batch.begin();
}
}
And I use it like this:
CheckedPolygon polygon = new CheckedPolygon(mStage.getCamera(), mTextureAtlas, new float[]{0, 500, 0, 0, 0, 500}, new short[]{0, 1, 2});
mStage.addActor(polygon);
I checked values from methods PolygonSprite.getVertices() and PolygonSprite.getBoundingRectangle() and got some weird outputs...
You create an invalid polygon with 0,500 being the first and last point.
So you need to chose valid vertices, for example:
new float[] {0, 0, 0, 500, 500, 500}
I created a small image to visualize it. The line on top is your "polygon", the triangle below is a polygon with the vertices from above:
The vertices you get back from the polygon sprite are otherwise ok, since they contain x, y, color, u, v.
I'm just now picking up jMonkeyEngine and I've encountered an issue I can't seem to solve.
In the simpleInitApp method in the main class, I can use the following code to successfully render a box:
Box playerBase = new Box(Vector3f.ZERO,1f,1f,1f);
Geometry playerBaseGeom = new Geometry("playerBase", playerBase);
Transform fixBaseHeight = new Transform(
new Vector3f(0f,(0.5f * 2f),0f));
playerBaseGeom.setLocalTransform(fixBaseHeight);
Material playerBaseMaterial = new Material(assetManager,
"Common/MatDefs/Misc/Unshaded.j3md");
playerBaseMaterial.setColor("Color", ColorRGBA.Yellow);
playerBaseGeom.setMaterial(playerBaseMaterial);
rootNode.attachChild(playerBaseGeom);
I tried to use a class called Tower to be able to spawn several boxes representing towers (for a simple tower defense game). The tower class looks like this:
public class Tower {
private static final float HEIGHT = 0.5f;
private static final float WIDTH = 0.2f;
private static final float DEPTH = 0.2f;
private Geometry towerGeom;
private Material towerMaterial;
private Box tower;
public Tower(AssetManager assetManager, float x_coord, float z_coord) {
tower = new Box();
towerGeom = new Geometry("tower", tower);
towerMaterial = new Material(assetManager,
"Common/MatDefs/Misc/Unshaded.j3md");
towerMaterial.setColor("Color", ColorRGBA.Green);
towerGeom.setMaterial(towerMaterial);
towerGeom.setLocalTranslation(x_coord, (0.5f * .5f),z_coord);
towerGeom.setLocalScale(WIDTH, HEIGHT, DEPTH);
}
public Geometry getGeometry() {
return towerGeom;
}
}
In the main class, in the simpleInitApp method, I tried to use my new Tower class like this:
List <Tower> towers = new ArrayList<Tower>();
towers.add(new Tower(assetManager, 10f,8f));
for(Tower t:towers) {
rootNode.attachChild(t.getGeometry());
}
However, no cube is rendered. Why? I used the exact same procedure shown in the beginning, which worked.
The Box() constructor is meant for serialization only and doesn't initialize the mesh. The constructor in your upper example is deprecated. Use:
tower = new Box(0.5f, 0.5f, 0.5f);
This will create a cube of the size 1x1x1 centered at [0, 0, 0].
Also, make sure you look at the tower. With the default camera position and the tower at [10, 0, 8], it will be placed behind you.
getCamera().lookAt( new Vector3f(10f, 0, 8f), Vector3f.UNIT_Y );
I recommend consulting the jME source code for this kind of problem so you can be sure whats going on.
I'm doing some initial experiments for a CS course, where I'm trying to use JBox2D as a physics library and drawing using JavaFX. I have had some luck draw circles that fall from the top of the screen, but now I have issues doing the same with rectangles (or any other shape).
I'm able to both draw and simulate, but I cannot figure out how to rotate the drawn nodes in JavaFX using values from the Body objects.
Here's my code for the bodies using JBox2D:
#Override
public Body createBody() {
BodyDef bd = new BodyDef();
bd.type = BodyType.DYNAMIC;
bd.position.set(centerX, centerY);
PolygonShape ps = new PolygonShape();
ps.setAsBox(2.0f,4.0f);
FixtureDef fd = new FixtureDef();
fd.shape = ps;
fd.density = 0.9f;
fd.friction = 0.3f;
fd.restitution = 0.5f;
Body b = PhysicalScene.world.createBody(bd);
b.createFixture(fd);
return b;
}
}
This is drawn using nodes in JavaFX - as written here:
#Override
public Node create() {
Rectangle r = new Rectangle();
r.setHeight(20);
r.setWidth(40);
r.setStroke(Color.RED);
r.setLayoutX(Physics.toPixelX(centerX));
r.setLayoutY(Physics.toPixelY(centerY));
// THIS IS WHAT I'M MISSING
// r.setRotate(/* some value from Body */);
return r;
}
The code isn't pretty, but I hope you get the idea. I am able to rotate the nodes by inserting arguments in the method, but do not know how to get these values from the Body objects themselves.
I hope you can help, thanks!
I am using Box2d for a game, and although I use large constants to set angular velocity, the fastest speed I can get is 1 revolution at 3.86 seconds.
I had checked my source code in the following thread and everything is the same with what I have been suggested from both users in here and in tutorials:
setAngularVelocity rotates really slowly
However than I noticed the following unresolved thread:
http://www.reddit.com/r/libgdx/comments/1qr2m3/the_strangest_libgdxbox2d_behaviour/
and noticed that might actually be the problem. Here is my dispose method
public void dispose() {
//Get Rid of Everything!
Assets.Clear();
GameEngine.Clear();
BallMap.clear();
PlayerMap.clear();
shapeRenderer.dispose();
debugRenderer.dispose();
world.dispose();
batch.dispose();
font.dispose();
}
They are all reinitialized on the beginning as follows:
this.game = game;
this.cameraWidth = cameraWidth*pixelRatio;
this.cameraHeight = cameraHeight*pixelRatio;
batch = new SpriteBatch();
shapeRenderer = new ShapeRenderer();
stateTime = 0F;
Scores = new Integer[]{0, 0};
debugRenderer = new Box2DDebugRenderer();
world = new World(new Vector2(0, 0), true); //Create a world with no gravity
GameEngine.setContactListener(world);
I navigate through screens with the following code:
public void create () {
scene_menu = new MainMenuScreen(this, cameraWidth, cameraHeight);
setScreen(scene_menu);
}
public void swtogame(){
scene_menu.dispose();
scene_game = new MatchScreen(this, cameraWidth, cameraHeight);
setScreen(scene_game);
}
public void swtomenu(){
scene_game.dispose();
scene_menu = new MainMenuScreen(this, cameraWidth, cameraHeight);
setScreen(scene_menu);
}
the way i initialize objects:
public Object(World world, short category, short mask, float x, float y, float radius, Sprite image,
float maxSpeed, float frictionStrength, float linearDamping, float angularDamping, boolean movable,
float elasticity, float mass){
this.world = world;
this.category = category;
this.mask = mask;
// We set our body type
this.bodyDef = new BodyDef();
if(movable==true){bodyDef.type = BodyType.DynamicBody;}else{bodyDef.type = BodyType.StaticBody;}
// Set body's starting position in the world
bodyDef.position.set(x, y);
bodyDef.linearDamping = linearDamping;
bodyDef.angularDamping = angularDamping;
// Create our body in the world using our body definition
this.body = world.createBody(bodyDef);
// Create a circle shape and set its radius
CircleShape circle = new CircleShape();
circle.setRadius(radius);
// Create a fixture definition to apply our shape to
fixtureDef = new FixtureDef();
fixtureDef.shape = circle;
fixtureDef.density = (float) (mass/(Math.PI*radius*radius));
fixtureDef.friction = frictionStrength;
fixtureDef.restitution = elasticity;
fixtureDef.filter.categoryBits = category;
fixtureDef.filter.maskBits = mask;
// Create our fixture and attach it to the body
this.fixture = body.createFixture(fixtureDef);
// BodyDef and FixtureDef don't need disposing, but shapes do.
circle.dispose();
... unrelated functions after that
}
Am I disposing correctly? Is this a bug? Is there any way to get around it and use the setAngularVelocity properly?
Because you haven't shown much code, I can I'm not 100% sure that I'm right, but I think that you are hitting the built in maximum movement limit of 2.0 units per time step. This means that at a typical framerate of 60Hz a body covering 2 units per timestep is moving at 120 m/s or 432 km/h (270 mph). Unfortunately it seems that there is no direct way to change this limit in Java, because this limit seems to be defined in the native C++ librarys.
But I think that the real problem is that you have a wrong scale. Box2D uses MKS (meters, kilograms, and seconds). And you may have used pixels instead of meters. The FAQ of Box2D suggests to use
objects [that are] between 0.1 - 10 meters
otherwise you can get strange situations.
See http://www.iforce2d.net/b2dtut/gotchas#speedlimit
and https://code.google.com/p/box2d/wiki/FAQ
I just found the problem, and it was pretty simple. Im just going to post this here for future googlers:
Object was actually rotating properly, the problem was in my drawing method, I didn't use conversion between radians to degrees in my batch.draw, and it interpreted everything in radians. I know such an amateur mistake! Thanks a lot for your time.