Creating chimney smoke and fire was one of the simplest yet effective VFX I created for Tales of the Shire. The smoke is purely shader based, and the fire is very similar but with some additional ember particle effects to supplement the main effect.
The smoke effect’s shader is driven by noise applied to a mesh tube in various layers which contribute to the colour, alpha and vertex offset. This noise is repositioned depending on world space so each chimney smoke placed in the world will form different shapes when viewed as a cohesive composition.
The fire shader is similarly driven by noise, naturally in different ways, to create a steadily dancing fireplace flame. Different parameters were set for a candle flame material for a more gentle effect.