Simulating Fire with Texture Splats
Abstract
We propose the use of textured splats as the basic display primitives for an open surface fire model. The high-detail textures help to achieve a smooth boundary of the fire and gain the small-scale turbulence appearance. We utilize the Lattice Boltzmann Model (LBM) to simulate physically-based equations describing the fire evolution and its interaction with the environment (e.g., obstacles, wind and temperature). The property of fuel and non-burning objects are defined on the lattice of the computation domain. A temperature field is also incorporated to model the generation of smoke from the fire due to incomplete combustion. The linear and local characteristics of the LBM enable us to accelerate the computation with graphics hardware to reach real-time simulation speed, while the texture splat primitives enable interactive rendering frame rates.
Current Results
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A simple camp fire generated using texture splats. In this example, around 100 display primitives are rendered. 32 different textured splats are used. Each display primitive is assigned with a texture splat randomly at the beginning of the simulation. |
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Smoke generally refers to a visible mixture of products given off by an incomplete combustion. The generation of smoke from fire is modeled by ways of a temperature field. To achieve fast speed, we use a linear equation, instead of a more accurate differential equation, to approximate the change of temperature for the display primitives. As the temperature of a display primitive decreases to a certain point, the fire particle changes to a smoke particle. The texture on it is kept unchanged. A separate color table is used to assign the color for smoke. |
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The left figure indicates the interaction of fire with the surrounding boundary objects. A kettle is placed above a campfire. We initialize a 4X4 patch as the inlet of the LBM grid with a velocity of 0.2. The kettle is placed as a boundary box into the grid. |
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The left video shows the dynamic changing of boundary conditions in the LBM model. Initially, the torch is stationary. As we increase the velocity field on the left side of the computation domain to a value of 0.1, simulating the wind effect, the shape of the fire becomes unstable. As the speed of the boundary condition is gradually reduced to 0. The shape of the fire becomes stable again. |
Extended Work