CompuServe Thread

#Reflection Mapping

13 messages in this thread
#189388From: Mike KelleySep 6, 1995 12:11 PM
>On Refraction Mapping front: I just rendered couple of Gems >(spent 1 hour on that exercise) and uploaded results: >you may want to check it out – REFRGEMS.JPG in IPAS Usage folder. They are truly beautiful, Aleksey, and one of the things I have always wanted to do with 3DS. Will you forgive me a few questions? 1) What is the exact way to go about creating such gems? Did you just create a regular solid (I have the full function HEDRA IPAS that does that), make it transparent and colored, and then apply your mapping IPAS? Or are there some steps I'm missing? Your message said it took you an hour to do the gems, and they are certainly worth the time, but I couldn't see what would take that long. Is positioning the object critical to the results? 2) How difficult is it to apply your mapping? 3) (This one really sounds stupid, but here it goes): What, exactly, *does* reflection mapping really do? I mean, I can see that I probably want it if nothing more than just to make gems like you did, but how does it differ from applying a refmap in the material editor? What other kinds of applications would I be likely to use it for? 4) How much and when available? Thanks for your patience.
#189391From: LEE STEELSep 6, 1995 12:47 PM
Hi Mike, I jumped in here because I have worked with the product for several months. I'm sure Alex will add some comments of his own. Lee 1)Typical Workflow: a. Create Geometry b. Render background (all objects which are NOT refractive). You use this image as your background AND the refractive material called from within the interface. You will take this background and create a material in the material editor and save it to use from within the Mapref interfave (PXP). c. If your object is to be made of (colored) transparent material or if your object will have specular highlights wou will need to create an appropriate material which is nearly 100% transparant and apply this directly to the (refractive) mesh. d. Call up the Mapref (PXP) dialog box and define your scene. Optical Density, Refraction Type, Raytrace Depth, Material (the background), Environment (floor, walls, etc….). After picking OK, the AXP is automatically applied to the mesh as well as the special mapping coords. e. Finally render the scene. 2) Mapping is applied by the routine. 3) It actually calculates how the background is reflected by the faces based on how many times rays are allowed to bounce around within the object. 4) Available NOW! Call Digimation.
#189404From: Mike KelleySep 6, 1995 2:28 PM
Ah, thanks for jumping in and enlightening me. So, this is really ray-tracing of a sort, huh? That kind of disappoints me, because of the speed factor. Can I assume that for the example Alex posted it would take several magnitudes of order longer rendering times than I'm used to? I would have guessed around 8 minutes or so on my Pentiums, but for a raytraced image an hour or hours would probably be closer?
#189408From: LEE STEELSep 6, 1995 3:06 PM
This is the exciting part, they have broken the sound barrier as far as render time goes. Average rendering time is under 1 min. on a P100!
#189481From: Aleksey PopelyukhinSep 6, 1995 9:47 PM
>So, this is really ray-tracing of a sort, huh? That kind of disappoints me, because of the speed >factor. Can I assume that for the example Alex posted it would take several magnitudes of order >longer rendering times than I'm used to? I would have guessed around 8 minutes or so on my >Pentiums, but for a raytraced image an hour or hours would probably be closer? Hi, again! Refraction Mapping is some sort of raytracing (just very smart and SPEEDY one). It cheats, where it can. One of the main achivements was determination of what is insignificant and throwing it away, another achivement was to make extremely speedy antialias – antijuggy techique, which is size adaptive. Actually, RefrMap is packed with unique and very efficient algorithms: Check the size of RefrMap.axp (without any interface it is 270K) versus let's say blobs.axp (which has some interface code embedded: 108K). And take into account that Russian programmers can be accused in anything, BUT writing bloated or slow code! Refraction Mapping is speedy, for objects of normal complexity and relative size you would expect around a minute (!!!) on Pentium/90. Regards, Alex, Video International
#189935From: Tim Krego, [pro.image]Sep 9, 1995 3:11 AM
>And take into account that Russian programmers can be accused in anything, BUT writing bloated or slow code!< That is what I heard. They don't release programs that are 20-30MB like some of this crap from MS and Lotus. The excuse over here is to get more RAM. At least 3DS gives you a good reason to get more RAM. Americans are pigs for bloated code. [BG]
#189473From: Aleksey PopelyukhinSep 6, 1995 9:37 PM
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
#189503From: Ernie JacksonSep 7, 1995 12:56 AM
>> You forgot to ask about the future… << You'd need to render a crystal ball w/ refmap to do that! <g> – ej
#189669From: Aleksey PopelyukhinSep 7, 1995 7:57 PM
>> You'd need to render a crystal ball w/ refmap to do that! <g> Work in progress!!!
#189786From: ALAN IGLESIASSep 8, 1995 11:37 AM
Aleksey, I just wanted you to know that I showed Refraction Mapping to the San Diego User's Group last night and it was very well received. Combining 3DS cubic reflection maps with your wonderfully thought out refraction mapping techniques provided a truly convincing, efficient solution without the need to raytrace. Something I've wanted to be able do in a scan-line renderer for a long time. Congratulations to you and Oleg! it is much deserved, and keep the great stuff coming! I've got this feeling MAX will be SO much more fun with you guys around. Sincerely, -Alan
#190361From: Aleksey PopelyukhinSep 11, 1995 9:01 PM
>>Congratulations to you and Oleg! it is much deserved, and keep the great stuff coming! I've got >>this feeling MAX will be SO much more fun with you guys around. Thanks, Alan! Hope, you will get many happy minutes(!) with our Refraction Mapping. But we don't stay still: Sticky Mapping is around the corner! Be ready! Alex, Video International
#189580From: Mike KelleySep 7, 1995 12:52 PM
Thanks, Aleksey, for the replies. I'll call Digimation today (hey, I always wanted to buy something made by you, since your thoughtful help on WB).
#189670From: Aleksey PopelyukhinSep 7, 1995 7:59 PM
>>hey, I always wanted to buy something made by you, since your thoughtful help on WB Thanks, but I always wanted you to buy something from us, based solely on our qualities…