A simple demo of OpegGL programming using depth map, textures and transparency. It s possible to control earth rotation using keys 4, 5 and 6, cube rotation using keys 1, 2 and 3, and camera rotation using keys q , d and 0 (zero). Cameras goes closer and further using keys i and o , camera goes up and down using keys z and s . -A simple demo of OpegGL programming using depth map, textures and transparency. It s possible to control earth rotation using keys 4, 5 and 6, cube rotation using keys 1, 2 and 3, and camera rotation using keys　q ,　d　and 0 (zero). Cameras goes closer and further using keys　i　and　o , camera goes up and down using keys　z　and　s .