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Container size
Size of the simulation volume.
You can press “Edit Container Area'' to enable resizing gizmos.
This parameter cannot be changed on “live” simulation instances.
Simulation Timestep
Controls the time interval between each simulation frame. Smaller values result in more frequent updates, providing a slower but smoother and more accurate simulation.
Simulation Iterations
Number of simulation iterations per simulation frame. The simulation does ⅓ of the smoke simulation per iteration, and extrapolates the smoke movement in time for higher performance while keeping smooth movement. To do a full simulation per frame you can set it to 3 iterations, which may be beneficial in cases where the simulation interacts with quickly moving objects.
Simulation Mode
Setting that determines the type of simulation being performed, with options including Smoke, Colored Smoke, and Fire. Smoke mode simulates a single colored smoke/fog/etc. Colored Smoke mode allows emitting smoke of a given color. Fire mode simulates smoke, fuel, and temperature components, allowing control of burning fuel to produce fire.
Grid Resolution
Size of the simulation grid.
This is the most important parameter for performance adjustment.
Higher size of the grid corresponds to a higher quality simulation, but results in higher VRAM usage and a higher performance cost.
Effective grid resolution shows you the size of your simulation grid.
VRAM usage and performance cost scales with effective voxel count.
Cell size shows the calculated size of each cell.
This parameter cannot be changed on the “live” simulation instance.
Run Simulation
Freezes simulation when disabled. Also decreases performance cost when disabled, since simulation won’t run. Disabling this option does not prevent simulation from rendering.
Run Rendering
Enables rendering of the smoke/fire. Disabling rendering decreases performance cost. Disabling this option does not prevent simulation from running.
Limit Framerate/Maximum Framerate
Limits the number of simulation frames per second to avoid excessive performance impact. Maximum Framerate setting specifies the desired limit.
Fix Volume World Position
When enabled, moving simulation volume will not disturb simulation. When disabled, smoke/fire will try to stay in place in world space. If you want to move the simulation around the scene, you want to disable this option.
Enable Render Downscale/Downscale Factor
Enables the usage of lower resolution for rendering to improve performance. The Resolution scale is controlled with the “Downscale Factor”. Recommended for mobile devices.
You can not set it to 1.0, if you want full resolution you must disable render downscale.
Current Injection Point
Specify at which point in the render graph should Smoke & Fire be rendered. Recommended options are: Before Forward Alpha if you want other transparent objects to be rendered on top of the Smoke & Fire, or After Forward Alpha if you want Smoke & Fire to be rendered on top of the other transparent objects.
Enable Render Downscale/Downscale Factor
Enables the usage of lower resolution rendering to improve performance. The Resolution scale is controlled with the “Downscale Factor”. Recommended for mobile devices.
You can not set it to 1.0, if you want full resolution you must disable render downscale.
Primary Light
Directional light that will be used for Smoke & Fire lighting. Must be set, otherwise simulation will not start. Can be freely modified at runtime.
Additional Lights
List of point lights that contribute to Smoke & Fire lighting. Can be freely modified at runtime. You can add up to 16 lights to that list.
Materials
Materials used to render Smoke & Fire volume, and optionally upscale rendered image when the Enable Render Downscale option is enabled. You can replace built-in rendering shaders by using those options, but it’s only intended for advanced Smoke & Fire users to do so. To use it you will need to create your custom version of Materials. If it is set to None in Editor it will revert back to the default value.
Smoke Density
Optical density of smoke. Higher values correspond to more opaque smoke. Note that emitters may emit both smoke and fuel, but they have separate density values. Smoke is also created as a result of fuel burning.
Fuel Density
Optical density of fuel. Higher values correspond to more opaque fuel. Note that emitters may emit both smoke and fuel, but they have separate density values. Only has an effect in the fire simulation mode.