> <i>1981 A first 3D game called Tempest is published</i><p>Battlezone is actual 3D, and 1980.<p>I'm not saying that is first, either, just that 1980 < 1981 and that Tempest is more of a form of 2.5D. (I remember it being an interesting, fast-paced game with good sound, but fundamentally it's just Space Invaders rolled into a tube.)<p>> <i>How to workaround too little RAM problem? Let’s load pixel graphics if player is far away and call it mip mapping:</i><p>MIP mapping is not primarily a RAM problem solving device. It's a way of precomputing the shrinking of texture images for when they appear in the distance, so that they don't have to be antialised on the fly.<p>Thus is a CPU saving device, and requires extra storage. However, not much more! The half-size texture needs only 25% more storage, and the quarter-size another 6.25% or so.<p>The renderer has to consider the depth and index into the appropriate scale of the texture. I don't remember all the details, but I see to remember that it's dynamic. Like when the textured surface is in deep perspective, the distant pixels are derived from the smaller scale data, while the near part from the larger scale.<p>It could save RAM if we can avoid the detailed textures for objects that require them and are all far away. I.e. lazily load the detailed texture as the objects are approached, and free the memory when they recede again.