CompuServe Messages

Hi, Mike! >>On Refraction Mapping front: I just rendered couple of Gems >> REFRGEMS.JPG in IPAS Usage folder. >They are truly beautiful, Aleksey. Thanks. >1) What is the exact way to go about creating such gems? Your message said it took you an >hour to do the gems, and they are certainly worth the time. Is positioning the object critical to the >results? 0. Why did I spend an hour? I stupidly invited my wife to judge intermediate results <g>. (she still doesn't like yellow one) Exact steps are: 1. Create Meshes (with Hedra, Hedra2, Booleans, Lofter, whatever). I spent half an hour, just playing with Hedra2 (I just love this Ipas). Add some lights and assign some normal 3DS mapping and transparent REFLECTIVE material to them (if you want reflection). I used around 30% biglake.gif. 2. Create gradient. You can use Gus Grubba's gradient designer for that, but I just rendered empty scene with gradient background from white to blue. 3. Create couple of REFRACTIVE materials (nontransparent, selfillum) with this gradient as a texture. I created 4 out of the same gradient, just changing RGB Tint. 4. Call Refraction Mapping PXP module (MapRef) and set RefrMap parameters. In my case, I needed 4 groups with one mesh in each one, because every stone had different REFRACTIVE material. Other setting I used: Hide Prototype: Off (I wanted reflection). Optical density: from 2.0 to 2.4 (almost perfect diamonds). Raytraced Depth: 2 (for green one 3). Horizon: Middle (I wanted more different colors in the stone, because "Near" would cause only small range to be picked up). 4a. I had simple box called Wall behind the stones (on the distance of 2 sizes of the green one). And I set "Wall Object" setting to Wall, and tell MapRef to Hide it. 5. I rendered 640×480 scene. RefrMap took 18 seconds for Green one, and from 5 to 12 seconds for others (Pentium/90). And that would be for every frame. But the smaller relative area occupied by stones, the shorter this time would be (it's proportional to area). Done. >2) How difficult is it to apply your mapping? I haven't seen anything EASIER <g>, with exception of Camera Mapping <bg>. You can try for yourself. There is file REFRLOOK.ZIP in IPAS Usage section. It has OK button disabled, and there is no "Scene Material" button, which is a great convenience, because it allows you to pick Refractive Material from the list of those in the scene. otherwise it is identical to final product. >3) What, exactly, *does* reflection mapping really do? What other kinds of applications would I be likely to use it for? a) First of all, GEMS is just UNINTENDED use of RefMap. I called it Hidden Treasures, because it was not in our minds. b) Refraction Mapping gives you BEST of both words: raytraced refraction brought to scanline editor and all that multiplyed by SPEED. In short, it takes an object, raytraces camera rays, till they hit background (and surrounding objects) and figures out how object mapping coordinates should be changed in order to produce the same picture, when prerendered background is applied as a texture. Again, you render everything in the scene without your let's say diamond. And then use this image as a texture for diamond. If you wouldn't change mapping coordinates on the diamond, you would get something wrong. Refraction Mapping recalculates these coordinates in such a way, that when you apply this image to your diamond, background looks distorted in the proper way. If that in not exactly clear, just download REFDEMO.ZIP – working demo and try to replace background bitmap and bitmap used in LENS REFRACT material to some (the same) flick (say walking bird). And see what you'll get. c) Refraction Mapping should be used efor every not VERY complicated scene suitable for raytracer, esspecially in animations. Magnifying glasses, just glasses, monocles, bottles, gems, water drops (you can use blobs instead of meshes), caricatures, watches, cockpits(?) these glassy semispheres around pilots, etc… >4) How much and when available? 250. Digimation sells it temporarily for 195. Since SIGGRAPH. >5) You forgot to ask about the future… Regards, Alex, Video International