The Inferno Spline Force operator allows you to inject spline-driven forces into an Inferno simulation.
Each force type applies its effect to voxels within a distance/falloff range from the nearest point on the spline. Each force type also supports an optional per-spline override curve, which modulates the force strength along the length of the spline from start (0) to end (1).
Affect magnitude %: controls the extent to which forces injected by this operator will affect the magnitude of existing velocities in the simulation, rather than just their direction. 0% means the Inferno Force operator will only affect the direction of velocities in the simulation, whereas 100% means magnitude and direction will be affected.
Conservation bias: controls the extent to which forces injected by this operator will be injected before/after the simulation’s conservation step. 0 means forces will be injected entirely before conservation, 1 means entirely after, and values between 0-1 means forces will be injected partially before and after.
Conservation, which removes velocity divergence in the simulation, can sometimes over-smooth strong forces that are injected. In scenarios where you want to exert finer control over how forces behave after conservation is applied, you can adjust the bias value to be greater than 0.
The Advanced rollout also provides per-channel relative controls that scale the overall force contribution based on local simulation values. Each channel can be enabled independently and configured with a min/max range and a curve defining how the channel value maps to the force multiplier.
Relative to density: when enabled, force strength will be scaled based on the local density value.
Relative to fuel: when enabled, force strength will be scaled based on the local fuel value.
Relative to temperature: when enabled, force strength will be scaled based on the local temperature value.
Relative to meshes: when enabled, force strength will be scaled based on proximity to the specified mesh objects.
Zero distance if inside volume: when enabled, voxels that fall inside the mesh volume will be treated as having zero distance to the surface, causing the relative force multiplier to use the minimum value for those voxels.
The inside/outside test performs a simple nearest-normal calculation to deduce whether a voxel is inside or outside of a mesh. This test may fail for open meshes, self-intersecting meshes, or groups of meshes that intersect each other. It works best on closed meshes that do not intersect.
Spline list: the list of spline objects to use as force sources.
Merge input splines: when enabled, all splines in the list will be treated as a single combined shape before force calculations are performed.
Spline resolution: the number of sample points generated per unit of spline length when voxelizing the spline for force calculations. Higher values produce more accurate results for curved splines.
Drag slows fluid motion near the spline by removing velocity from voxels in the influence region.
Drag %: the percentage of velocity removed from voxels near the spline each step.
Distance: the distance from the spline within which voxels are fully affected.
Falloff: the additional distance beyond which the effect diminishes to zero.
Override effect along spline: when enabled, the drag strength will be modulated along the spline length using the curve editor.
Pull applies a force toward the nearest point on the spline, drawing fluid inward.
Clamp %: when enabled, the magnitude of the pull force applied to each voxel will be clamped to the specified percentage of its current distance from the nearest spline.
Pull force: the strength of the pull force applied toward the spline.
Distance: the distance from the spline within which voxels are fully affected.
Falloff: the additional distance beyond which the effect diminishes to zero.
Override effect along spline: when enabled, the pull strength will be modulated along the spline length using the curve editor.
Follow applies a force along the spline direction at the nearest point, causing fluid to move along the spline path.
Follow force: the strength of the follow force applied along the spline.
Distance: the distance from the spline within which voxels are fully affected.
Falloff: the additional distance beyond which the effect diminishes to zero.
Override effect along spline: when enabled, the follow strength will be modulated along the spline length using the curve editor.
Swirl applies a rotational force around the spline axis, causing fluid to orbit around the spline.
Swirl force: the strength of the rotational force applied around the spline.
Distance: the distance from the spline within which voxels are fully affected.
Falloff: the additional distance beyond which the effect diminishes to zero.
Override effect along spline: when enabled, the swirl strength will be modulated along the spline length using the curve editor.
Pressure injects an outward pressure value into the simulation near the spline, which the pressure solver then converts into velocity.
Pressure: the pressure value injected near the spline.
Distance: the distance from the spline within which voxels are fully affected.
Falloff: the additional distance beyond which the effect diminishes to zero.
Override effect along spline: when enabled, the pressure strength will be modulated along the spline length using the curve editor.
Noise injects spatially-varying random forces near the spline. When enabled, the Noise rollout becomes visible and provides noise configuration settings.
Noise: the strength of the noise force applied near the spline.
Distance: the distance from the spline within which voxels are fully affected.
Falloff: the additional distance beyond which the effect diminishes to zero.
Override effect along spline: when enabled, the noise strength will be modulated along the spline length using the curve editor.
Only visible when the noise force is enabled. Configures the noise field used to generate spatially-varying force directions near the spline.