You can animate the Intensity parameters using the standard particle type animation controls: Birth, Absolute, and Age. See Animating Particle Type Parameters.
You can apply noise to each particle type to make random variations in the particles’ spacing and movements. Noise is simply randomness that is calculated mathematically. There are two patterns of noise that you can apply to particles: Brownian and Perlin.
Brownian noise is a “random walk,” like a jitter. It’s not completely random, but its movements are more general than Perlin. This random walk basically consists of steps in a random direction, with each step length having some characteristic value. Instead of having a totally random value at each frame, you offset the previous value by a random step amount. In the case of particles, this is a random 3D vector direction and scale. This offset is applied to whichever Intensity parameter you’ve specified for the noise: Position, Velocity, or Acceleration (see the next page for information).
Perlin noise has spatial coherence, meaning that several different particles in roughly the same location in space tend to have similar noise added to them (with Brownian, each particle is independent of the others). It interpolates between the random values. This creates a more controlled look, such as a “streaming” effect that can be achieved with noise. With Perlin, there is more structure to the noise while still appearing fairly random.
To add noise to particles
1. Open the particle type’s Particle Type property editor.
2. On the Noise page, set the following parameters:
3. Select the noise pattern Type: Brownian or Perlin (see previous description).
4. Set the Intensity:
- Position: amount of noise to be added to particles’ position (in Softimage spatial units).
- Velocity: amount of noise to be added to particles’ velocity (in [Softimage spatial units]/[Softimage time units])
- Acceleration: amount of noise to be added to particles’ acceleration (in [Softimage spatial units]/[Softimage time units]^2)
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You can animate the Intensity parameters using the standard particle type animation controls: Birth, Absolute, and Age. See Animating Particle Type Parameters. |
5. If you selected Perlin as the pattern type, you can also set these parameters:
- Iteration: number of iterations of the turbulence algorithm (1 is a simple Perlin function).
- Scale: spatial correlation of the particles.
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To create the effects of little trails, set the Scale value to 0.1 or lower. |
- Power: amplitude of the turbulence.
Autodesk Softimage v.7.5