The Particle Age and Particle Distance Effects Rollouts

These rollouts give you access to a wide range of controls by which you can modify the character of your PC effect, and with these controls, the gradient controls really come to fore. Although a more detailed discussion of these controls is not possible here, the on-line manual discusses them at length, and is rich in examples of their use.

The Particle Age Effects controls [figure 15] permit the modification of the PC effect over the length of the lives of the individual particles forming the basis for your effect.

The four gradients in this panel allow you to modify the radius (up to the maximum set in the Shapes panel), luminosity, color mix and life color of the effect. These setting are critical to the formulation of a realistic effect and are quite powerful. A very basic example of the age effect can be seen in Figure 16.

All three effects are identical in their rather brute-force composition except for modifications in this panel: the quite ugly plume on the far right has Particle Age Effects turned off, and the other two have almost directly opposed settings in the radius gradient control, with the particles on the left set to grow in radius as they age and those in the middle set to shrink.

The Particle Distance Effects controls [Figure 17] allow the adjustment of the radius, luminosity, color gradient and gradient of your effect based on the particles?distance from the emitter, their distance from the emitter plane, and/or their radial distance from the emitter, and include settings for the Near and Far ranges based on the trueSpace units in your scene.

For the radius functions of the Particle Age and Particle Distance Effects, the real-time Preview mode toggled in the Shapes rollout is a great aid, and the Preview Window toggled in the main PC rollout, via its birth-death slider, affords a hint of how the color and luminosity functions in the Particle Age effects affect the individual ‘puffs?in your effect. Nonetheless, until, and even after, you get the knack of the gradient controls you’ll find test area renders in your main or subsidiary viewports important for tweaking your PC effects with the controls in these rollouts.

A critical element in producing convincing PyroCluster effects rests in its highly configurable Fractal Noise engine, controlled through the Fractal Fury rollout [Figure 18].

Based on seven types of fractal noise (Gaseous, Fire, Electricity, Regular, Fractal, Turbulence and fbmFractal) selected via the Type dropdown, you can alter the fundamental character of the texture of your effect, and by engaging the Color function in this rollout, which again is controlled by a gradient sub-panel, you may alter the coloring of the effect utilizing the particular noise generated by your Type selection. It is likely that the for great majority of the effects you set out to build, you will engage the Fractal Fury function, and the additional thirteen controls here allow you to adjust your settings to increase the realism of your effects, as well as to create a variety of highly unusual special effects.

In the Illumination rollout you can determine how, and to what degree, your effect responds to the lights in your scene (if at all). If you engage illumination for the effect you are creating, you may select from one of three types of lighting, each of which is highly configurable: Diffuse, Ray or Bump. The latter applies a special type of Phong shading to your effect, with adjustable specular highlights and surface deformations [Figure 19].

The Exclusion control allows you to determine which lights in your scene will have an impact on your effect, and the Attenuation control allows setting their fall off-in relation to the effect.

With PyroCluster’s Attenuation controls you may select and fine tune the fall-off of selected, or all, lights in relation to a specific PC effect. You may select between no attenuation, the trueSpace attenuation as set in the light’s properties panel, or a much more precise attenuation dictated by the settings you adjust in the attenuation dialog, which opens in response to the switch in the illumination panel. If you select PC attenuation, you may set Near settings (i.e. the points at which the light begins in the radius around the light source and the point at which it reaches its maximum intensity) and/or Far settings (i.e. the points at which the light begins to diminish and at which it fades completely).  You may also toggle between three Decay settings: None (in which case attenuation is determined completely by the near and far settings); Inverse decay and Inverse Square decay. With the latter two settings, unless Near attenuation is set manually, decay begins at the light source.  In both cases, however, selecting a decay setting overrides any Far settings you have made. All of these settings may be applied electively to any or all of the lights which are included as affecting the specific PC effect in the main illumination exclude/include dialog by assigning the attenuation settings to the lights in the attenuation dialog.

The Show toggle in the attenuation dialog controls a wire-frame type preview mode, much like in the preview mode of the shapes dialogue, where real time visual representations of the near and far parameters are made visible to aid in your adjusting these settings, as demonstrated in [Figure 19a].

Such precise control of light attenuation as it affects a specific PC effect is a very useful tool for controlling the final appearance and realism of the effect.  It is particularly effective in instances where a light is placed within an effect as its chief or internal source of illumination.  Two examples of this use may be seen in figures [19b and 19c] where identical PC effects and identical lights differ only in the attenuation settings.

Note that the illumination settings determined here are not directly related to the luminosity setting in the Globals panel, which is independent of the lights in the scene and is utilized to adjust for the tendency of dense volume effects to render darker than more transparent effects.

Unfortunately, PyroCluster effects, by themselves, are not sources of light. However, strategic placement of lights within or around the effect can go a long way toward creating the illusion that the PC effect is a light source. An example of the difference between PC effects with and without this type of light placement can be seen by comparing the two renderings of a quick experiment I put together utilizing TrueParticles  and PyroCluster. The first image [Figure 20] relies on several lights external to the exploding sphere for its illumination, and the second [Figure 21] relies on lights within the sphere, in the heart of the two PC effects (smoke and fire) for the majority of illumination in the scene. While a compromise between the two would, in the end, probably be more satisfactory, these two extremes demonstrate the range of possibilities.

A number of interesting affects may be generated in this fashion. For example, using a particle system, such as TrueParticles, that allows lights as Selected Objects, create a particle system with a selected light set to render with glows or lens flares. Assign a PC effect to the system, perhaps a light cloud effect, and render away!

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