source: other-projects/nz-flag-design/trunk/render-3d/Flag_files/snow.js@ 29475

            var particle;
            var particleImage = new Image();

            var particles = new THREE.Geometry(),
                pMaterial = new THREE.ParticleBasicMaterial({
                color: 0xFFFFFF,
                size: 15,
                map: THREE.ImageUtils.loadTexture(
                    "./images/snow.jpg"
                ),
                blending: THREE.AdditiveBlending,
                transparent: true
            });
    
        
        
            function snow() {
                    
                //var material = new THREE.ParticleBasicMaterial( { map: new THREE.Texture(particleImage) } );
                    
                for (var i = 0; i < 500; i++) {

                    particle = new THREE.Vector3();
                    particle.x = Math.random() * 2000 - 1000;
                    particle.y = Math.random() * 2000 - 1000;
                    particle.z = Math.random() * 2000 - 1000;
                    //particle.scale.x = particle.scale.y =  1;
                    
                    particles.vertices.push(particle); 
                }
                particleSystem = new THREE.ParticleSystem(
                particles,
                pMaterial);
                
                particleSystem.sortParticles = true;
    
                return particleSystem;
            }

            //

            function updateSnow() {

            for(var i = 0; i < particles.length; i++)
                {

                    var particle = particles[i]; 
                    particle.updatePhysics(); 
    
                    with(particle.position)
                    {
                        if(y<-1000) y+=2000; 
                        if(x>1000) x-=2000; 
                        else if(x<-1000) x+=2000; 
                        if(z>1000) z-=2000; 
                        else if(z<-1000) z+=2000; 
                    }               
                }
                
            }