When a star brightness changes suddenly the scattered light from the surrounding cloud does not reach us all at the same time. It is delayed based on the total distance traveled and the speed of light. The result is called a light echo. To better understand how a light echo works I created a simulation of one.
One can create spiraling motions for particles using expressions. This method propagates a local up vector for the curl so that the twist direction does not go through pole flipping as the particle changes direction.
Here is the vein brush from my unfold presentation, along with help on creating brush presets.
As promised here are the scene files from my Unfold presentation along with some brief descriptions.
I've modified the roman candle scene in my previous post to use lights positioned at particle locations for illumination, along with further refinements.
Here is a simple example that uses Maya nParticles and Fluids to simulate a roman candle.
One can use nParticles to create a jiggling Jello substance that can be sliced using an nConstraint with breakable bonds. The workflow is relatively quick and easy.
This scene file shows an easy set up for a relatively fast to simulate boiling water effect using Maya Fluids.
The trail of a torpedo is tricky to do because it combines fluid dynamics, surface and volume rendering as well as fog and light scattering.