Posted by hedgehog on Mar 20, 2014; 11:38am
URL: https://forum.jogamp.org/Can-t-Get-Lighting-to-Work-in-Ardor3D-tp4031971p4032005.html

The pasted code below tweaks ManyLightsExample by setting all light colours to white. It also fills the colour buffers of all object spheres to red.

All object spheres are grey - the same as what I'm seeing in my own code and GridExample.

How do we modify ManyLightsExample2 to see red spheres as the lights pass by?

import java.util.Random;

import com.ardor3d.bounding.BoundingSphere;
import com.ardor3d.example.ExampleBase;
import com.ardor3d.light.PointLight;
import com.ardor3d.math.ColorRGBA;
import com.ardor3d.math.MathUtils;
import com.ardor3d.math.Vector3;
import com.ardor3d.scenegraph.MeshData;
import com.ardor3d.scenegraph.Node;
import com.ardor3d.scenegraph.Spatial;
import com.ardor3d.scenegraph.controller.SpatialController;
import com.ardor3d.scenegraph.hint.LightCombineMode;
import com.ardor3d.scenegraph.shape.Sphere;
import com.ardor3d.util.ReadOnlyTimer;
import com.ardor3d.util.geom.BufferUtils;

/**
 * A demonstration of randomly placed spheres being illuminated by numerious PointLight sources.
 */
public class ManyLightsExample2 extends ExampleBase {
    private final Random rand = new Random();
    private Node colornode;
    private final double worldsize = 20;

    public static void main(final String[] args) {
        start(ManyLightsExample2.class);
    }

    @Override
    protected void updateExample(final ReadOnlyTimer timer) {
        _root.sortLights();
    }

    /**
     * Create a randomly positioned light and lightsphere with a controller
     *
     * @param i
     *            Index of the light
     */
    void randomLight(final int i) {
        // Chose the color for the lights.
        //final ColorRGBA lightColor = ColorRGBA.randomColor(new ColorRGBA());
        final ColorRGBA lightColor = new ColorRGBA(1,1,1,1);

        // Create a sphere to show where the light is in the demo.
        final Sphere lightSphere = new Sphere("lightSphere" + i, 9, 9, .1f);
        lightSphere.setModelBound(new BoundingSphere());
        lightSphere.getSceneHints().setLightCombineMode(LightCombineMode.Off);
        lightSphere.setDefaultColor(lightColor);

        // Create a new point light and fill out the properties
        final PointLight pointLight = new PointLight();
        pointLight.setAttenuate(true);
        pointLight.setConstant(.01f);
        //pointLight.setConstant(.1f);
        pointLight.setLinear(.001f);
        pointLight.setQuadratic(.1f);
        pointLight.setEnabled(true);
        pointLight.setDiffuse(lightColor);
        pointLight.setAmbient(new ColorRGBA(.1f, .1f, .1f, .1f));
        //pointLight.setAmbient(new ColorRGBA(.9f, .9f, .9f, 1f));

        _lightState.attach(pointLight);

        lightSphere.addController(new SpatialController<Spatial>() {

            double timeX = rand.nextDouble() * Math.PI * 8;
            double timeY = rand.nextDouble() * Math.PI * 8;
            double timeZ = rand.nextDouble() * Math.PI * 8;
            double speed = MathUtils.nextRandomDouble();

            public void update(final double tpf, final Spatial caller) {
                timeX += tpf * speed;
                timeY += tpf * speed;
                timeZ += tpf * speed;

                final double xPos = Math.sin(timeX * 0.4) * worldsize;
                final double yPos = Math.cos(timeY * 0.5) * worldsize;
                final double zPos = Math.sin(timeZ * 0.6) * worldsize;

                caller.setTranslation(xPos, yPos, zPos);
                pointLight.setLocation(xPos, yPos, zPos);
            }
        });

        // Add the light to the world part 2.
        colornode.attachChild(lightSphere);
    }

    /**
     * Create a random sphere to be affected by the light
     *
     * @param i
     *            Index of the sphere
     */
    void randomSphere(final int i) {
        // Crate a sphere and position it.
        final Sphere sphere = new Sphere("sphere" + i, 18, 18, MathUtils.nextRandomDouble() * 1.75 + 1.25);
        sphere.updateModelBound();
        sphere.setTranslation(new Vector3(rand.nextDouble() * worldsize * 2 - worldsize, rand.nextDouble() * worldsize
                * 2 - worldsize, rand.nextDouble() * worldsize * 2 - worldsize));

        ColorRGBA sphereColour = new ColorRGBA(1,0,0,1);
        MeshData meshData = sphere.getMeshData();
        int numberVertices = meshData.getVertexCount();
        meshData.setColorBuffer(BufferUtils.createColorBuffer(numberVertices));
      for (int index=0; index<numberVertices; index++)
      {
      float red = sphereColour.getRed();
      float green = sphereColour.getGreen();
      float blue = sphereColour.getBlue();
      float alpha = sphereColour.getAlpha();
      meshData.getColorBuffer().put(red).put(green).put(blue).put(alpha); // note *4 indexing into buffer
      }
      meshData.getColorBuffer().rewind();
       
        _root.attachChild(sphere);
    }

    @Override
    protected void initExample() {
        _lightState.detachAll();
        _lightState.setTwoSidedLighting(true);
        _lightState.setLocalViewer(true);

        rand.setSeed(1337);

        // Now add all the lights.
        colornode = new Node("LightNode");

        for (int i = 0; i < 40; i++) {
            randomLight(i);
        }
        // Add the spheres.
        for (int i = 0; i < 30; i++) {
            randomSphere(i);
        }

        _root.attachChild(colornode);
    }
}