html5的canvas实现3d雪花飘舞效果

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;
}
}

camera.position.x += ( mouseX – camera.position.x ) * 0.05;
camera.position.y += ( – mouseY – camera.position.y ) * 0.05;
camera.lookAt(scene.position); </p>
<p> renderer.render( scene, camera );</p>
<p>
}