CompuServe Messages

#VistaPro

    29-Aug-93 20:37:59
Sb: #54935-#VistaPro
Fm: John Hinkley 72466,1403
To: Mike Kelley 71302,73
Mike (and anyone else who's interested), A typical "good" Vistapro image consists of 1 to 10 _MILLION_ 3D polygons. I have rendered images with as many as 150M polygons. The density of the polygons varies with the camera position. For instance, a tree near the camera will be be generated with many more polygons than a tree that is far away. So, in a sense, each scene of a VP3 animation is a seperate 3D world unto itself — although they're all related of course. Vistapro is designed to render realistic (or not) looking landscapes, it's not a general purpose 3D renderer. It has many optimizations and limitations based upon this goal. 3DS does what it does very well, but it's not designed to do what Vistapro does. That said, I'm am currently adding DXF as an output format to Vistapro. I expect this feature will be used as David Taffet indicates: Use the DXF landscape as a guide for placing other objects and generating camera paths, then either throw away the landscape or use it as a matte. Then use a Vistapro image(s) as a background(s) and use 3DS to render the foreground(s). The one thing you won't have is accurate shadows cast upon the Vistapro background. I spoke with Gary Yost a few days ago and he indicated that "shadows on mattes" was on their wish-list for 3DSr3 but it didn't make it. Oh well, maybe in rev 4! When saving a landscape as a DXF file you have control over the amount of detail and the area covered (always rectangular though) by the DXF file. If the indicated area will turn out to be more than 64K points or faces (the limit for a single object in 3DS and AutoCAD) Vistapro will automatically save it as several smaller objects. As the code is currently implemented, you will not have "smooth" joints between the seperate objects (for those of you who will want to actually render the landscape) but I _DO_ have a painless solution for that. Well, painless to you guys anyway! If you want to, you can save several small areas out in high detail and they will be loaded into their proper locations (relative to each other) by 3DS. The DXF objects I create do not contain the 3D trees or 3D fractal detail that Vistapro generates. Even so, the DXF files are very large: A small Vistapro landscape at "full" detail (polygon size 1 for those of you who use Vistapro) makes a 15MB DXF file with 66000 points and 130000 faces. A huge landscape is 1M points, 2M faces, and a 250MB DXF file. If I saved out all the trees and fractal detail in that 150M polygon rendering that I mentioned above would make a DXF file of around 60GB! One small consolation though: once you have loaded the DXF file into 3DS you can save it out as a 3DS object and it will take up only 1/5 as much space. Some other things in the works include the ability to save the colors (that Vistapro would have put on the landscape) as a TGA, PCX or GIF file that you can use as a texture map in 3DS. These too can grow very large if you want lots of detail. I also plan to create utilities to translate Vistapro Camera scripts into 3DS format and vice versa. I may add the ability to load the DXF objects that I save — but generally not other DXF files. The executables I sent to a few people for testing was named VP4.EXE but I did that just be sure they didn't accidentally overwrite their existing VP3.EXE. VP4 won't ship until sometime next year, but I'm considering a 3.1 upgrade for those of you who need some of the new features sooner. Enhancements that are already in it are: optimization for the Pentium, smoother animations at slow camera speeds and DXF output. Later on I plan to add anti-aliasing, maybe field rendering, and the ability to have Vistapro spawn a batch file after rendering and saving each frame of an animation — this will give you the ability to process the last rendered image, send it to a single frame recorder, whatever you can do from a batch file. I'm open to suggestions and input from anyone… Please keep in mind that Vistapro is MUCH less expensive that 3DS — so don't expect me to do everything that it does! John.