Here's an interactive model that allows setting trees on fire.
Check out a paper that discusses a novel method for the combustion of botanical tree models. Tree models are formed as connected particles for the branching structure and a polygonal surface mesh for the combustion. The proposed system makes sure that each particle stores biological and physical attributes leading to the kinetic behavior of a plant and the exothermic reaction of the combustion.
"Coupled with realistic physics for rods, the particles enable dynamic branch motions," wrote the team. "We model material properties, such as moisture and charring behavior, and associate them with individual particles. The combustion is efficiently processed in the surface domain of the tree model on a polygonal mesh."
The best thing is that users can dynamically interact with tree models by initiating fires and by inducing stress on branches. The model is said to run at interactive rates and support multiple tree instances in parallel.