Reactivity

In Graviton, the relationships between various sands is always what happens to me based on neighbors and parameters around.

Therefore, a material such as fire, simply has a characteristic BURNS, and that's it. It's the other sand whose rules define what occurs when they touch Fire or sand that BURNS.

This one-way relationship keeps things simple, but also introduces some complications. What about the famous Game Of Life rules? There, it is not just Game_of_Life - sand turning to Empty but also Empty turning to Game_of_Life. This is solved by modifying the rules of Empty.

To create two-way behavior, you need to add such behavior to both sand materials.