Fuel works like a cloud of combustible gas like propane or gasoline mist. When it burns, it...

Fuel Masking allows you to control where fuel burns. The Fuel Mask is a cloud taken from any other channel, smoothed and re-mapped. Only within that cloud the fuel will burn. This allows you to control ignition and suffocation of burning fuel.


Check this to enable simulation and caching of the fuel channel.

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If the Adaptive Container option is enabled, this value defines the minimum temperature that will cause the container will consider non-empty. If this value is zero, no voxels containing temperature will be lost. However, often shading settings are such that low values aren't visible anyway. In this case, increasing this threshold allows the sim to keep the container smaller.

Fuel Diffusion

Specifies how fast fuel diffuses (see Temperature/Diffusion above for more details).

Burn Rate

Specifies the amount of the fuel that is burnt in every frame. The faster it burns, the more Burn and Temperature will be created.

Burn Rate works like linear decay in the Burn channel

Fuel Mask Channel

If a channel is selected, fuel masking will be active.

See the simple-ignition example for a setup using the Burn channel.

Fuel Mask Smoothing

Before using the selected channel as a fuel mask, it can be smoothed or blurred. This will also make the cloud a bit larger, thereby propagating the ignition front like you would expect it to.

Fuel Mask Mapping

Re-mapping the smoothed fuel mask gives you control over the shape of the fuel mask and how steep the ignition front is. A flat increase will let the burn start slowly the larger the fuel mask values become. A steep increase will makwe the fuel burn at the full burn rate as soon as it touches the fuel mask.


A factor that specifies how much the gas expands per burnt voxel of fuel.

Temp. Emission

Specifies how much heat is generated per unit of burnt fuel.

Density Emission

Specifies how much density is generated per unit of burnt fuel.