Saturday, 19 January 2008
The AtariXL scene produces maybe the most impressive demos I have ever seen running on an 8bit machine. I was wondering why this machine can display 4 times more complex 3ds than the C64 for example who share the same CPU but it is 1.5 times slower than the XL. Those demos usually use the 320kb memory expansion where there may be a possibility for cheating by precalculating lot's of data. That would be one explanation for this.
One of the most impressive demos I have seen recently on the XL is The Shrine by laresistance. You can also watch a youtube video of the real thing running this beauty! Simply stunning!!!
Of course the XL demos mostly use a smooth shade of a single color, either blue, red or green, producing great shades for polygon lighting or other newschool 2d effects. Most of the times they use big pixels of 4*4 size (Or it is 2*4 in a pixel width that occures in a 160*200 resolution (I don't know if the XL also shares this resolution but the pixel width looks like C64 multicolor or the Mode 0 of CPC)). Maybe there is a video mode that makes it easier to output such pixel block, much easier and less CPU wasting than the ways used in C64 or CPC to achieve this? Who knows..
But then we can see some great smooth fullscreen crosszooms (also used in a fractal zoomer) but the quality of the 3d scenes is stunning! We can see a 3d sierpinski gasket, shaded, with proper polygon clipping rotating in your face with a fairly good speed, which is an object that is stunning for an 8bit. Even in Amiga/AtariST 16bit demos it's not too common to see such 3d models in demos. Usually you see cubes, pyramids and 3d models with 10-20 polygons, not 80 in your face! Not even the later scenes where a background, a great floor mapper and some 3d structures like a zigurat, an easter island head or the stonehedge are combined together to create an outworld environment. I also like the environment mapped spike object with the reflection on the floor in the beginning. Simply awesome code for an 8bit and not only!!!
But maybe there is a secret magic in the atari hardware and lot'sa memory that makes this possible :)