PREAMBLE 12/23/91 After an apparantly unsuccesful media blitz to get some response out of other Raytrace users, I've decided to scrap the idea of a paper based newsletter. My hopes of building a library of the best Raytrace files has also been tempered a bit - at this point, I'll be glad to share whatever I've got with whomever is motivated enough to share something of thiers. (Gawd, now I know how share- ware authors feel when contributions don't come rolling in...) As a program, GFA Raytrace is at a junction in its life, GFA will not continue to refine it unless we can garner another round of interest, sales, and enthusiasm for it. I'm hoping it's not too late - the imminent release of a TOS2.x upgrade, as well as the continued evolvement of the ST line threaten to make the program obsolete, and I want to do whatever I can to insure that Raytrace will at least be able to run all of the 68000 based machines. Even a few letters sent to GFA Germany from other Raytrace users may be enough to encourage the minor tweaking needed for TOS 2.x compatibility. I'm encouraging everyone reading this to PLEASE take the time - put your word processor and printer to work - and let GFA and the program's author Dirk Van Assche know support of Raytrace is important. I know you're out there! I check the Number of Accesses to the files I've uploaded to the Genie and Compuserve libraries, so an interest in Raytrace does exist. I feel less of a One Man Band judging by the numbers, so I'm continuing this quest. Below is a conglomeration of everything I've written over the past two months to generate and revive interest in the program. I hope you find it informative and helpful... ****************************************************************** WHY A GFA RAYTRACE USER GROUP? As an avid Raytrace user, I am interested in contacting other users, sharing operational tips, and seeing some of the creations others have been able to produce with the program. I feel that by forming an informal sort of user group, we can all benefit from each other's experience and get the most out of our purchase. My primary motivation right now is to find talented GFA BASIC programers to produce a converter for Raytrace pics, so we are not permanently trapped in Raytrace's format. More on this later... Finally, it is my hope to build a library showcasing the talents of Raytrace users, and making it availiable to anyone who is interested enough to send in a disk of thier work to contribute to the library. An informal user group indeed! All that will be required is a floppy disk of your Raytraced creations: Rendered full screens, wireframes, or texture maps to get back the best of stuff I hope to receive from other Raytrace users. CONVERSION UTILITY UPDATE My main reason for posting this newsletter is to garner the talent needed to write a GIF/Spectrum conversion utility for Raytace users. Ideally one that converts .SUL files to Spectrum 512 uncompressed format is much needed and long overdue. However, a well written 16 color converter might also be a viable alternative. A utility thats included with Spectrum 512 called SPU2DEG.TTP does a fairly good job of analyzing a Spectrum uncompressed pic and reducing it to 16 colors. Either or both are needed. And since no one to my knowledge has ever produced such a program for Raytrace pics, I've begun a campaign to get one written. Thanks to Les Player of GFA UK who recently attended a meeting at GFA Germany and interceded on our behalf asking to have the secrets of Raytrace file format revealed. It has been agreed to make some of the program's source code availiable to developers who request it, thereby making an analysis of Raytrace's file format possible and bringing us one step closer to a GIF/Spectrum or 16 color converter. Many thanks to Dirk Van Assche and GFA Germany for being open and willing to make this information availiable. Able developers who are fluent in GFA BASIC and GIF/Spectrum pic format should contact Les Player of GFA UK or John Barger of GFA USA for further info on obtaining the code needed to help write the converter. IN THE MEANTIME... I've been hacking away (an understatement) at the sample GFA BASIC code included with v2.1 to display an uncompressed Raytrace pic. Rather than the original brain-dead code that only allowed viewing a single pic called 'DEMO.SUL", I've added a File Selector routine to choose pics to view in sequence, and a few civilized alerts thrown in. Still no compressed pic support, let alone conversion abilities - but a nice utility to have, and a way to share your Raytrace creations with other ST owners. Do a search on the keyword "RAY" in the GEnie ST or Compuserve's ATARIARTS libraries and you should find RAYWIEW included with sample pics to download. UPDATE NOW! Are you using the latest version of GFA Raytrace? Perhaps you bought a copy liscenced by Michtron years ago and have stayed with it. But there are reasons to make sure you've got the latest V2.1 release. First and foremost is speed. As you may have read in your manual, Raytrace was written in a combination of Assembly and GFA BASIC. As GFA BASIC's complier has been improved, the authors recompiled the source code for a 30% speed improvement. Support was also added for TOS 1.4 and for the STE so it won't crash on bootup - it is the only version that will run on later versions of TOS. (Bad news for those contemplating a Mega STE though, Raytrace refuses to load and appears to be a conflict with TOS 2.x.) The Blitter of the STE and earlier Mega's is automatically turned on to assist redraws of the menus and editor screens, though it doesn't impact the speed of calculations. Transparent objects have been added to the materials list, as well as a 'Rainbow' option to modify the effect of colored lamps on your rendered scenes. To upgrade, contact GFA USA for how they want to handle it. The offical upgrade price is $39.95, about half of Raytrace's list price here in the states. For a better deal, call GFA UK who has slashed prices on Raytrace to 10 pounds sterling, about $20 at current conversion rates. With airmail postage, I upgraded to V2.1 for about $25 and got to keep the old Michtron version as well. Cheap and handy if you have a VISA card to do the currency conversion for you. Very fast too, I received my copy in less than 5 days! If, *and only if* you are using an early ST with TOS 1.0 and plan to stay with it awhile, E. Arthur Brown & Company is offering an earlier version of Raytrace liscenced to Michtron for $19.95. An economical way to give Raytrace a trial run. They can be reached M-F CST on thier toll-free (orders only) line at 1 (800) 322-4405. IF YOU HAVE A MODEM... GENIE subscribers are welcome to stop by the GFA Category in the Atari ST Roundtable. I have started a discussion of GFA Raytrace in Category 22, Topic 4. Join us there and share your hints and tips on getting the most out of Raytrace, and keep up to date on seeing if we're making any progress getting a converter written. TEXTURE MAP TIPS Checkerboard ground patterns have long been the mainstay of raytrace programs, but Raytrace's ability to load ground and sky patterns, and apply texture maps to some object types will add even more interest to a rendered screen. Here's some tips to using them effectively: - Deluxe Paint ST has a wonderful gradient fill option that makes 16 color blue skies and glowing sunsets a snap to create. - Load Neo and Degas pics into a paint program that antialiases. Mapped pics have a tendency to give a grainy, pixelated appearance when rendered, antialiasing will help compensate. - Use simple, clearly defined pics. A map, sky or ground is best with a minimum of colors. The more colors used, the more likely that 'color problems' will appear. - Learn how ground patterns are laid down. A ground map's size is directly influenced by the Edit/Edit Ground/Size finction. Maps that are a close-up of a texture should use a small or medium ground size. Maps that aren't should use a larger ground size to preserve detail. Create a pic with a bordered square in a paint program, load it as a ground, and raytrace it. Change your ground size, and trace again. Try this: raise your observer and raytrace again to see how the angle of view affects the perspective of the grids. A low observer gives more depth to the view, while a higher observer gives a cleaner view of your pattern. - Because smaller ground maps are reduced and laid side by side, for the effect of a continuous surface patterns must line up properly on *all* screen edges when you are creating a map in a paint program. A good test example is to use a wide line in your paint program and stretch it diagonally from corner to corner. Load it as a ground, raytrace, and you will see how the lines run contin- uously back into the horizon. - To insure continuous patterns are pixel perfect on all edges, cut a brush about 1/8" thick along the entire edge of a screen and paste it to the opposite side. This will show you what changes need to be made to your pattern to get proper line-up edge to edge. - To create a tiled ground, create an image with a solid color border all the way around the edge. This will also give a clear view of how Raytrace places pics onto the ground surface grid. - Create your maps according to thier use: Ground patterns and texture maps need to be magnified close-ups of the effect you're trying to create in order to preserve the detail when being rendered to less than full screen size. Generally, Sky patterns don't need twiddling since the sky will map the full width of the screen without vertical distortion. Keep your horizon at mid screen or lower to avoid horizontally smooshing the image excessively. WHEN A GROUND IS NOT A GROUND I've been able to create some interesting effects by placing a large rectangle as the base of a scene instead of using the Ground fuction. By mapping a woodgrain or tile pattern onto a properly placed rectangle, and then experimenting with the Transparent or Mirror percentages is possible to produce the effect of a freshly waxed, shiny floors who's patterns show through, but also reflect the objects sitting on them. Also, a rippled deep blue pic will map to a watery surface using this technique. Both are geat ways to add more realism to your rendered scenes. From the side view its best if your rectangle angles down slighty so its lower at the Observer's end for a good perspective. If your Observer is too high, you will still see the map pattern but will not get the full effect of the surface quality. From the front view, a properly placed map should appear as a 1" high rectangle the width of the window, and as a trapeziod in the perspective view. I regret Raytrace locks the user out of the Print Screen function, it would be nice to be able to include .NEO snapshots to help illustrate some of the techniques described above. If anyone is aware of a snapshot program that bypasses the ALT-HELP routine and can be used within Raytrace, please send it my way! TEXTURE 'BANDITS' NEEDED ! Members who have access to Amigas and color Mac systems should be on the lookout for collections of Texture Maps. Because each of these systems have a broader range of Raytracing programs to choose from, more colors, higher resolutions, and are popular Multimedia machines, there are examples of exquisitely detailed renderings of wood, marble, brick, et. al. that could be grabbed and converted to Atari formats. Ideally the images would be converted to GIF on their native machines, and once in that format could be transferred to ST's and processed with any of several PD conversion utilities. A hand scanner or even a video digitizer are also means of getting textures onto disk for further editing in a paint program. If anyone has success in doing this, please take the time to send them on disk for the library so that other members can benefit. SPEEDING UP CALCULATION TIMES Raytracing is perhaps the most processor intensive application ever done on the ST. GFA Raytrace is certainly the fastest and leaves anything I've seen in the public domain in the dust - it doesn't require overnight number crunching sessions. But there's an awful lot of trial and error involved in getting a rendering just right. Selecting 1/4 or 1/8 scale to test a tumbnail view quickly is the best approach. However, color problems may not appear until a scene is calculated full size - a long time to wait to see that adjustments are needed. Raytrace benefits greatly from an accelerator, and I've had success with ICD's AdSpeed STE, nearly halving calculation times. But it is a very tricky process, requiring an external switch to control when the accelerator is in 8 or 16 Mhz mode. GFA Raytrace's unique screen with split low and meduim rez is the culprit here, the program will crash if 16Mhz is enabled when displaying the main F2 RAYTRACE menu. (Also the 512 color-picker option must be avoided at 16mhz!) So if you are planning on adding an accelerator, it must support an external switch. Just be sure the accelerator is off when moving to the Raytrace menu. Also, the system will crash at the end of a calculation when the menu returns. Either throttle down before the last line is calculated, or more simply, select the DO AND SAVE option first. Your picture will be safely saved before the split rez menu returns and the program crashes. The fact that v2.1 of Raytrace won't even load on a Mega STE hints its a problem of not recognizing the TOS version rather than the presence of the built in accelerator. And it seems unlikely that Raytrace will run on machines that will have the TOS 2.06 upgrade installed. It's really important that someone other than just me makes a point of letting GFA know that compatibility with the Mega STE TOS is *essential* if Raytrace is to survive. It's unfortunate, just as Atari delivers the kind of horsepower raytracing really needs, GFA appears to be neglecting the program. Particularly tragic since the support of a floating point math chip in a Mega STE could turn an hour rendering into a few minute job. The hardware is availiable to support it: Atari's SPF004 module for the Mega, JRI's 68881 board, the AdSpeed STE's option, and the socket built into the Mega STE - are all implemeted the same way, accessing a 68881 FPU as a memory mapped peripheral. Certainly something GFA should support if Raytrace is ever updated. Raytrace apparantly messes with the FPU's address, just having the chip installed in my AdSpeed STE causes Raytrace to crash at the split rez screen, if I remove the chip it runs fine... TAKING IT TO THE TOP Once again, here's where to call or write for upgrades to V2.1, to request further updates to Raytrace, or to get more info on GFA's other great products: GFA SYSTEMTECHNIK GMBH GFA DATA MEDIA UK GFA SOFTWARE TECH. Heerdter Standburg #30 Box 121 27 Congress Street D4000 Dusseldorf 11 Wokingham Berkshire Salem, Republic of RG11 1FA MA 01970-5523 GERMANY ENGLAND USA Dirk Van Assche Les Player John Barger To call GFA: America 1 (800) 776-6GFA Fax: 1 (508) 744-8041 Direct Dial Germany (using ATT long distance): 011 49 211 55040 Direct Dial England (using ATT long distance): 011 44 734 794941 HOW TO REACH ME Write to: GFA RAYTRACE USERS USA c/o Nick S. Smith 4406 5th Avenue South Minneapolis, MN 55409-2124 I can be reached on GEnie 24 hours/day by sending mail to S.SMITH65 On Compuserve, my mail address is 70412,2667