Note: The following introduction to Cebas's Pyrocluster plugin  was written concurrent with its release for trueSpace 4.3.  In the update for trueSpace 5.2, neither the fundamental principles of Pyrocluster usage, nor its interface, have changed. Consequently, in order to make the following guide available in a timely fashion upon the release of the update, the original trueSpace 4.3 screenshots have not been revised to conform to version 5.2. This should in no way affect a user's capacity to follow the discussion.  The text has been slightly edited from its original form.

In the discussion below, terms specific to functions or operations within Pyrocluster are in bold-face on the occasion of their first appearance.

Simply put, an awful lot of us like to watch things catch fire, blow-up, or otherwise undergo the extremes of rapid oxidation. I’m sure a complex analysis of why this is the case could be conjured up by those with framed photos of Freud and/or Jung on their office walls, hanging just above those three-figure an hour couches, but I prefer just to think of it as one of those primal needs: the attraction of the fire after the day’s hunt is done, the source of the shadows on the wall of Plato’s cave.

For the handful of us graying trueSpace users who can remember times before such things were taken away from us by legal restrictions, trying to manifest this attraction in the world of CG may arise in part from a hearkening back to the sights and smells of summer backyard fireworks spectacles, singed fingers and all, or the pure joy of watching an amateur rocket we labored over and built by hand roar into the sky and successfully deploy its chute, or a homemade pyrotechnic device make just that explosion and effect we were striving for. And for even more of us, raised on or immersed by choice in a world of film and television special effects and stunts, it’s the compulsion to replicate… no, surpass what we’ve seen on the big and little screens

Effectively bringing this appealing world of fire, explosions, smoke, steam, and complex atmospherics to our work with trueSpace, whether for commercial, creative or recreational purposes, formerly posed a challenge, characterized by tricky and often marginally effective workarounds. Steam or smoke? Well, get your paint program, work up the texture, map it to a plane with some transparency, and well, maybe it might look - somewhat close to – something similar to smoke. What? You want that pale imitation of real smoke to move as part of your animation? Well, then animated textures are the way to go. Say that again, you want the camera to fly through the smoke? Well, there’s always a particle system, with some motion blur. Yeah, I know, it’s a pain and really not quite the same. And you want to add ground fog and volumetric light to the scene? Well…I guess post-processing outside of trueSpace might help you fake it. Or will it all end up being just too ‘fake’?

Happily, things have changed, and this challenge has an effective answer. Cebas Computer, of Eppelheim, Germany (http://www.cebas.com/) has now brought to trueSpace 4.3 and 5 users the power and versatility of PyroCluster® (or PC), incorporating, and expanding upon, the technologies first developed for their market-proven plugin for Discreet’s 3d Studio Max. PyroCluster finally makes possible the creation of a broad range of true volumetric fire, smoke, haze, fog, cloud and other atmospheric and pyrotechnic effects within a trueSpace scene or animation. And frankly, it’s pretty exciting.

This article is intended as a general introduction to PC for those who are unfamiliar with it, to provide a general tour of its UI and some of its principal features, and to say a few words...well probably more than a few...about getting off the ground with it. 

With power comes complexity, and PC has it’s share of complex nooks and crannies to find your way around in. Fortunately, PC is accompanied by an innovative and very detailed html online-help file, complete with sophisticated animated and full-color examples. If you can, print that file out (it’s something over 150 pages in print), live with it – it will be your friend. A thorough acquaintance with the functions of PC will save you time in both set-up and rendering, and will also place in your hands the tools you need to produce an almost infinite range of PC effects. Fortunately though, within minutes of authorizing your installation, using presets and fairly self-evident variations from those presets, you can be knocking out simple PC effects in trueSpace like those below. And after a few hours of  poking around among the variables, you'll be capable of creating effects exceeding in effectiveness any of the workarounds trueSpace users have had to make do with heretofore:

This collective rendering of basic PC effects will be referred to again further on in this article, so it should be noted here and now that the shadows at work in this rendering are intentionally not consistent with a real-world lighting situation. Some of the effects are set to cast or receive shadows, others are not, and those that are affected by shadows have different include/exclude settings for lights in the setup so that the effects would not be obscured by the multiple shadows that would be caused were they all to be responding to the same lights.

A General Overview

PyroCluster functions in trueSpace scenes and animations via the assignment of a PC effect to an object in that scene, whether that object is a simple primitive, a complex mesh, or, most effectively, a particle system. PC hops out of the box equipped with its own native and quite sophisticated particle system, but is also compatible with Primitive Itch’s widely-used Primal Particles (http://www.primitiveitch.com/), and with Sisyphus Software’s powerful particle system plugin, TrueParticles (http://www.sisyphus.com/).

The assignment of a PC effect to an object or particle system is made via PC’s Automatic Analytical Binding System – oops, did I hear a groan when I dropped those polysyllables on some of you? Well, I could have just as well said "by moving your cursor over the intended object and clicking on it." It’s that simple, and like many of the truly complex and amazing PC operations that go on behind the UI and add up to the fire we want to light, or the atom bomb we want to set off, or the blanket of evil, oily haze we want to have settle over the city in our scene, we can choose to either chew on and try to understand all those algorithms, or simply get to work/play and create something. Here, I’m going to opt for the work/play and leave the algorithm-chewing for the extra-credit questions on the final exam.

PyroCluster is accessed via the Cebas Plug-in-Manager, which itself is accessed through the standard trueSpace TSX panel.

The Plugin-Manager [Figure 2] gives unified, easy access to all the separate PC elements and functions, and is the interface through which, via the specific tabbed panels visible up top, you access subsidiary panels (which are all in the form of highly efficient rollouts that facilitate smooth access and conserve screen space), and create and modify all those elements: the PC effect, the native particle system (Spray), the specialized A-Bomb particle system, and the various modifiers/helpers for the Cebas particle systems - Gravity, Wind and Deflectors. It also gives access to the Global Shaders (there’ll be much more about this very critical element later) and a utilities panel, which at this point is occupied only with a Time-Utility. 

The final main element of the Plugin Manager is the Animate button, Yes, PyroCluster effects, and the almost endless modifications that they may undergo, may be animated! It is imperative, however, to note that they do not support trueSpace’s ‘autorecord’ function. Instead, any parameter and modification may be animated by keeping active the animate button, which remains visible no matter which of the Plugin Manager’s panels you are working with.

PyroCluster’s native particle system [Figure 3] and its sophisticated offspring, A-Bomb, were developed specifically for use with PC and differ from other particle systems like TrueParticles and Primal Particles in that they create no additional geometry in the scene - the particles are simply position and vector points of reference for the effect and therefore, if you want only the PC effect to be visible, need not be made invisible when rendering time rolls around. In all other regards, the main particle system features familiar standard adjustable parameters, as do the two deflectors (planar and spherical) and gravity and wind functions.

To create a particle system, you need only click in the scene under construction and draw the emitter, positioning it while drawing it if you wish, or more accurately later with the object move tools. The type of emitter (plane, box, sphere or cylinder) can be selected either before or after creation, or even changed well along in the scene’s construction to alter the nature of the eventual effect. In that case, you simply select the emitter with the object tool or through the KFE, and then access the particle system’s parameters through the Modify panel. And here’s a hint to users unfamiliar with particle systems that may be working on a still image rather than an animation: create your emitter and then assign it a negative start time, adjusting it and the other relevant variables "to taste." That saves you from having to advance forward through an animation to reach a satisfactory point in the system’s life for the still image you are creating…a particularly cumbersome method if your image contains many different particle systems.

[Figure 4]

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