3d world coordiantes to screen coordinates returns wrong value

I have a simple project to render a 3D model (simple cube) using Perspective camera in android. The model is rendered fine but I need to get its coordinates on the device screen. Using project method of the perspective camera returns the wrong x value which is out of bounds of the viewport (2048*1536), but for the y value it works fine. How can I achieve the right x,y screen coordinate from 3d model?

Vector3 red_cube;
private void loadModel() {

	ModelInstance m1 = new ModelInstance(createPointModel(Color.RED));
	red_cube = new Vector3(516326, 423652, 1200);
	m1.transform.setToTranslation(node2);
	
	modelInstances.add(m1);
}

Vector3 loc = new new Vector3(516340, 423635, 1200);
Vector3 dir = new float[]{220, -80, 0};

@Override
public void render() {

	if (!isLoaded) {
		loadModel();
		isLoaded = true;
	}
	Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT | GL20.GL_DEPTH_BUFFER_BIT);
	Gdx.gl.glViewport(0, 0, Gdx.graphics.getWidth(), Gdx.graphics.getHeight());
	
	Vector3 v = camera.project(red_cube);
	Log.d("red_cube:", v.x + ", " + v.y);

	Vector3 pointing = OrientationSensorFusion.getDirection(dir);
	camera.position.set(loc);
	camera.direction.set(pointing);
	camera.update();
	
	modelBatch.begin(camera);
	modelBatch.render(modelInstances, environment);
	modelBatch.end();
	
}

The returned value by the project method is -2314.235, 767.8047.

[Tom-Ski]

Your test is still not valid.

I changed the test to be conformant with what we require for issues, and there is no issue. https://pix.asidik.com/tomski-wGxLyR.mp4

Updated valid test:

import com.badlogic.gdx.ApplicationAdapter;
import com.badlogic.gdx.Gdx;
import com.badlogic.gdx.backends.lwjgl3.Lwjgl3Application;
import com.badlogic.gdx.backends.lwjgl3.Lwjgl3ApplicationConfiguration;
import com.badlogic.gdx.graphics.Color;
import com.badlogic.gdx.graphics.GL20;
import com.badlogic.gdx.graphics.PerspectiveCamera;
import com.badlogic.gdx.graphics.VertexAttributes;
import com.badlogic.gdx.graphics.g3d.Environment;
import com.badlogic.gdx.graphics.g3d.Material;
import com.badlogic.gdx.graphics.g3d.Model;
import com.badlogic.gdx.graphics.g3d.ModelBatch;
import com.badlogic.gdx.graphics.g3d.ModelInstance;
import com.badlogic.gdx.graphics.g3d.attributes.ColorAttribute;
import com.badlogic.gdx.graphics.g3d.attributes.DirectionalLightsAttribute;
import com.badlogic.gdx.graphics.g3d.environment.DirectionalLight;
import com.badlogic.gdx.graphics.g3d.utils.FirstPersonCameraController;
import com.badlogic.gdx.graphics.g3d.utils.ModelBuilder;
import com.badlogic.gdx.math.Vector3;
import com.badlogic.gdx.utils.Array;

public class Scene extends ApplicationAdapter {

	PerspectiveCamera camera;

	ModelBatch modelBatch;
	Environment env;

	Vector3 redCubeTranslation = new Vector3();
	Array<ModelInstance> modelInstances = new Array<>();

	FirstPersonCameraController firstPersonCameraController;

	Vector3 temp = new Vector3();

	@Override
	public void create () {
		redCubeTranslation.set(10, 0, 10);

		cameraInit();
		modelBatch = new ModelBatch();


		loadModel();

		firstPersonCameraController = new FirstPersonCameraController(camera);
		Gdx.input.setInputProcessor(firstPersonCameraController);

		env = new Environment();
		env.set(new ColorAttribute(ColorAttribute.AmbientLight, 0.4f, 0.4f, 0.4f, 1f));
		env.add(new DirectionalLight().set(1f, 1f, 1f, 1, 1, 1));

	}


	private Model createPointModel (Color color) {
		Model pointModel;
		ModelBuilder modelBuilder = new ModelBuilder();
		int s = 1;
		Material material = new Material(ColorAttribute.createDiffuse(color));
		long attributes = VertexAttributes.Usage.Position | VertexAttributes.Usage.Normal;

		pointModel = modelBuilder.createBox(1f * s, 1f * s, 1f * s, material, attributes);
		return pointModel;
	}


	private void loadModel () {
		ModelInstance m1 = new ModelInstance(createPointModel(Color.RED));
		m1.transform.setToTranslation(redCubeTranslation);
		modelInstances.add(m1);
	}

	@Override
	public void render () {

		Gdx.gl.glClearColor(0.2f, 0.2f, 0.2f, 1f);
		Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT | GL20.GL_DEPTH_BUFFER_BIT);
		Gdx.gl.glViewport(0, 0, Gdx.graphics.getWidth(), Gdx.graphics.getHeight());

		temp.set(redCubeTranslation);
		camera.project(temp);
		System.out.println("Red cube screenspace position: "+ temp.x + "  " + temp.y + "  " + temp.z);


		firstPersonCameraController.update(Gdx.graphics.getDeltaTime());
		camera.update();

		modelBatch.begin(camera);
		modelBatch.render(modelInstances, env);
		modelBatch.end();
	}


	private void cameraInit () {

		camera = new PerspectiveCamera(67, Gdx.graphics.getWidth(), Gdx.graphics.getHeight());
		camera.near = 1f;
		camera.far = 500f;
		camera.update();

		camera.position.set(0, 0, 0);
		camera.lookAt(redCubeTranslation);
	}

	public static void main (String[] args) {
		Lwjgl3ApplicationConfiguration config = new Lwjgl3ApplicationConfiguration();
		config.setWindowedMode(1280, 720);
		new Lwjgl3Application(new Scene(), config);
	}

}

[NasserTahani]

Dear @Tom-Ski I’ve created a simplified version of my application which includes the problematic part. Regarding the project file size, I’ve included only the src folder of the Android project in the zip file. You can see the negative and out of bound values if you change the orientationValues = new float[]{220, -80, 0}; in the Scene class. It would be gratefull if you could take a look at it. src.zip