Flaming Trees in Far Cry® 4
When people are considering using SpeedTree in a game, they often ask us questions like these: Can SpeedTree destroy trees? Knock them over? Burn them? The answer: “Well, no. But it can help.”
Destruction requires a high level of interaction between the SpeedTree asset and other parts of the engine, and can’t really be handled by SpeedTree by itself. Consider a car colliding with a tree. There are so many things to consider (does it knock the tree down? Just shake it a little? What happens to the car? Does it catch on fire? Does the tree catch on fire if it does?) that it becomes much more of a “world” simulation problem than simply a tree problem. Many systems have to come together to pull that off. Collision detection, physics, fire simulation, vegetation rendering, particle rendering, and others have to work in concert to create a believable environment.
We try to help by providing data beyond just meshes and materials that can be accessed either at run-time via the SDK or in the tools pipeline via the Modeler and Compiler. Examples include collision volumes for fast hit detection, rigged skeletons for more detailed physical simulations, and user data fields on materials that can store custom fields like a “flammability” value. We also provide a custom exporter pipeline via the Modeler and/or Compiler that provides access to both mesh data and internal data not accessible via common mesh formats (e.g., node hierarchy, wind data, etc.). Our goal is to give your team enough data to implement features you feel are critical to your game.
As an example, take a look at the video below. I captured this shot of burning vegetation from the PlayStation® 4 version of Far Cry 4. The developers and artists at Ubisoft have created a fantastic environment once again and we’re proud that SpeedTree was at least a small part of it. I don’t know any details on how they pulled this off, but it does show that SpeedTree can be part of an interactive world.
And, just because the game is beautiful, here are a few more Far Cry 4 shots: