Path: utzoo!attcan!uunet!lll-winken!elroy.jpl.nasa.gov!usc!wuarchive!udel!haven!wam!walrus From: walrus@wam.umd.edu (Udo K Schuermann) Newsgroups: comp.sys.amiga Subject: Re: Imagine Message-ID: <1990Dec13.201243.4265@wam.umd.edu> Date: 13 Dec 90 20:12:43 GMT References: <15449@ddnvx1.afwl.af.mil> <1990Dec3.220339.6699@wam.umd.edu> <36704@cup.portal.com> <10747@helios.TAMU.EDU> <86758@tut.cis.ohio-state.edu> <61534@masscomp.ccur.com> Sender: usenet@wam.umd.edu (USENET Posting) Reply-To: walrus@wam.umd.edu (Udo K Schuermann) Organization: University of Maryland at College Park Lines: 102 In article <61534@masscomp.ccur.com> mark@calvin.westford.ccur.com (Mark Thompson) writes: > >Well quite frankly, when I first saw Imagine at Siggraph this year, I >was totally unimpressed. The animation control in JourneyMan was vastly >superior and LightWave's rendering capabilties made Imagine look like a >toy. Too bad you feel this way. Imagine is anything but a toy. I have not seen JourneyMan, but you have made me curious. If it's really that superior to Imagine, I'd like to see it! >But I am open minded and hoping someone can convince me that this >is no longer true because I have considered purchasing it just for its >object editors. Could someone possibly detail some of its more stellar >features? Keyframe cycle animation, meaning it's very easy to create objects that perform a certain range of motion repetitively (such as an ant or human walking, a locomotive's wheels, piston engine, etc). Boolean operations involving objects cuts objects along their intersections into multiple pieces, each of which can be used or discarded as needed. >Can it do reflection mapping (not ray-traced reflections) or >transparency mapping? Both. It is accomplished by mapping an IFF picture onto the object. The IFF picture's colors define the value of the reflectivity and/or transparency. This is also the way that bump mapping is implemented, as well as color mapping (image wrapping). >How are explosions accomplished? The object is algorithmically separated into its individual triangular face components, which are exploded away from the center according to a variety of parameters, which include control over how much the faces spin while they fly away. This is also the method used for Ripple, where an object's surface undergoes the wave effects seen on a flag in the wind or the water when a stone is dropped in. >What do you lose rendering in scanline mode? True reflectivity, refraction and CAST shadows. A scene renders much faster in Scanline mode. You still get brightside/darkside effects on objects. >What antialiasing support is there? A user controlled "edge level" value which determines how much effort the program spends on antialiasing. You could set it to 0 and get none for faster traces, then raise it high for final results. >Will it accept or output objects in formats other than its own? Imagine reads/writes only TDDD format which is read by at least one PD (or is it Shareware?) program named TTDDD can read/write this format to produce or process ASCII files. It's fairly easy to convert these to other formats. I am working on one to convert from decwrl OFF format to TTDDD. But no, Impulse does not provide such programs. >And how fast is >it (lets do some benchmarks)? If I have to wait over 20 minutes for a >high quality image, it is too slow. Benchmarking will be difficult because lighting, positioning, and the properties of objects can affect the rendering time greatly. Here are a few bits, though, which may be useful to you: My system: 68030/68882 @ 32MHz A red ball, just about filling the entire display, rendered at 352x470 interlaced HAM in Scanline required: 2 min 22 sec The same images scaled down to 64x64 pixels took 5 seconds. Before you leap with joy: this is a single object, a totally primitive scene. I have a scene with a very large diamond (12 faces) has a disturb texture on it (to produce obvious flaws in the mostly transparent material), three spheres, a multi-color pyramid, and all this on a black ground with a thick grid texture mapped onto it. A torus with an explode effect on it goes into several hundred facets that fly outward. The scene requires about 15 minutes in Scanline mode at 352x470 interlaced HAM. Another scene with a crystal sphere, multiple reflective objects, others with roughness and some with brushes wrapped onto them, as well as three light sources, takes (again at 352x470) about 40 minutes in full trace mode. Summa summarum: Full traces with refraction, object reflection, and cast shadows require more time, and for these 20 minutes is only possible if you have relatively simple scenes. An unaccellerated 1000, 500, or 2000 will not be too impressive. Despite all this, Imagine is a fine product, although still suffering from Young-Product-Problems. It is *far superior* to Turbo Silver, and truly a joy to use. Creating objects and animations with it is child's play! ._. Udo Schuermann "How is American beer similar to making love in ( ) walrus@wam.umd.edu a canoe?" -- "Both are f***ing close to water."