EmitterSphereShape cause a freeze

Hello,

I’m a beginner.
Some parameters of EmitterSphereShape class cause a freeze of the application.

With this example, everything works :

[java] import com.jme3.app.SimpleApplication;
import com.jme3.effect.ParticleEmitter;
import com.jme3.effect.ParticleMesh;
import com.jme3.effect.shapes.EmitterSphereShape;
import com.jme3.material.Material;
import com.jme3.math.ColorRGBA;
import com.jme3.math.Vector3f;

public class HelloEffects extends SimpleApplication {

public static void main(String[] args) {
    HelloEffects app = new HelloEffects();
    app.start();
}

@Override
public void simpleInitApp() {
    ParticleEmitter emitter = new ParticleEmitter("Test", ParticleMesh.Type.Triangle, 400);
    emitter.setShape(new EmitterSphereShape(new Vector3f(0, 0, 1), 1f));
    Material material = new Material(this.assetManager, "Common/MatDefs/Misc/Particle.j3md");
    material.setTexture("Texture", this.assetManager.loadTexture("Effects/Explosion/flame.png"));
    emitter.setMaterial(material);
    emitter.setParticlesPerSec(400);
    emitter.setImagesX(2);
    emitter.setImagesY(2);
    emitter.setRotateSpeed(2);
    emitter.setGravity(new Vector3f(0, 1f, 0));
    emitter.setSelectRandomImage(true);
    emitter.getParticleInfluencer().setInitialVelocity(new Vector3f(0, 2f, 0));
    emitter.getParticleInfluencer().setVelocityVariation(0.5f);
    emitter.setStartColor(ColorRGBA.Orange);
    this.rootNode.attachChild(emitter);
}

}[/java]

But with the parameters below, this is not the case :

[java] emitter.setShape(new EmitterSphereShape(new Vector3f(0, 0, 1), 0.5f));[/java]

What’s going on?