Pyro Sources, Colliders and Forces¶

Configure volume sources, collision objects and force effects that create, block or move Pyro fields.

Use the Emitters, Colliders, and Effects tabs to add objects that create, block, push, pull, or shape the volume. The Effects tab contains the Pyro force effects described below.

Lists and Nodes¶

In Lists, add and order entries in the Emitters, Colliders, and Effects tabs. In Nodes, use Pyro Source, Pyro Collider, and the individual named Pyro force nodes, then connect their outputs to the matching multi-input sockets on Pyro Domain. Only connected nodes contribute to the branch. Common controls appear on the node body and the complete conditional settings are in the Inspector.

A Pyro Source can take a Particle Stream input. When connected, that exact particle-emitter branch becomes the source, and the branch must also continue to the particle Simulation Output. Without that link, the source uses its regular object, Blender-particle, or Pro Particles selection controls. Pyro Data Mapping is built with connected mapping nodes in Nodes and with the local ordered mapping stack in Lists.

Emitter List¶

• Add Emitter: creates a new smoke/fire emitter.
• Duplicate: duplicates the selected emitter setup.
• Remove: removes the selected emitter from the Pyro scene.
• Enabled: temporarily disables an emitter without deleting it.
• Object: the mesh, curve, empty, or particle source object that emits smoke or fire.
• Automatic motion tracking: Pyro detects static, rigid T/R/S, and deforming source motion automatically. Static geometry is cached, rigid sources send transforms only, and deforming geometry is refreshed when needed.
• Shape: chooses how the source emits volume.

Emitter Shapes¶

• Box: emits from the object's bounding box.
• Sphere: emits from a spherical area around the source.
• Mesh: emits from the real mesh shape. Use it when the silhouette matters.
• Particles: emits from a Blender particle system or from a Pro Particles group.
• Curve: emits smoke along a Blender curve path.
• Spiky Burst: creates procedural radial spikes for explosions, muzzle flashes, or stylized shock shapes.
• Geo Nodes Points: emits from points generated by a Geometry Nodes modifier.

Mesh, Box, and Sphere Emitter Controls¶

• Fill Mode: chooses whether the emitter fills the object volume or only emits from the surface.
• Mesh emitters using Volume fill automatically repair small openings and minor surface defects for simulation. Flat or unrepairable volumes pause live simulation and identify the source object.
• Use Weight Map: uses a vertex group or a FLOAT attribute on the mesh POINT domain to control where surface emission is strongest.
• Weight Map: selects the vertex group or names the FLOAT point attribute used as the emission mask. This can also consume an effect map written by a Pyro collider.
• Surface Push: launches smoke away from the surface when using surface emission.

Box and Sphere surface emission, Surface Push, and rigid-object motion are supported by both Sparse and Fast Dense. Mesh emitters continue to use their full mesh voxelization path.

Curve Emitter Controls¶

• Sample Points: number of emission points along the curve.
• Radius: thickness of the emitted smoke along the curve.
• Start %: where along the curve emission begins.
• End %: where along the curve emission ends.

Fast Dense follows the sampled curve segments instead of approximating the source as one straight line. Animated curve motion is detected automatically; Inherit Motion controls how strongly it contributes to emitted velocity.

Spiky Burst Controls¶

• Burst Direction: main direction for the burst.
• Spread Angle: how wide the spikes fan out.
• Spike Count: number of procedural spike directions.
• Initial Size: radius of the dense core at the center of the burst.
• Length: base length of each spike.
• Length Randomization: random variation in spike length.
• Thickness: base thickness of each spike.
• Thickness Randomization: random variation in spike thickness.
• Seed: changes the generated spike layout.
• Animated Burst Frames: grows the burst over the first frames instead of appearing instantly.
• Spike Velocity Boost: pushes smoke along each spike direction.
• Tip Velocity Boost: gives extra speed near the spike tips.

Spiky Burst uses the selected Density, Heat, Fuel, and Velocity emission modes in both solver modes. Fast Dense includes both the burst core and the individual spikes.

Particle Source Controls¶

• Particle Source: chooses whether the emitter reads Blender particles or Pro Particles.
• Particle System: selects a Blender particle system on the source object.
• Group: selects a Pro Particles group by name. In Nodes, a connected Particle Stream labels this control Group Filter. Choose All Groups to read every group from the selected particle source.
• Use Particle Color: transfers particle color into the emitted smoke.
• Use Particle Radius: uses particle size as the emission radius.
• Override Radius: uses a fixed radius when particle radius is not used.
• Velocity Multiplier: scales how much particle motion is inherited by the emitted smoke.
• Smooth Fast Emitters / Emission Substeps: samples fast-moving particles multiple times per frame to avoid broken smoke trails.

Geometry Nodes Points Controls¶

• Geo Nodes Points: reads point positions from a Geometry Nodes modifier output.
• Use Radius Attribute: reads each point radius from an attribute.
• Radius Attribute: name of the attribute used for point radius.
• Override Radius: fallback radius when no point radius attribute is used.
• Use Color Attribute: reads per-point color from a named attribute.
• Color Attribute: name of the attribute used for color.
• Velocity Multiplier: scales velocity from point motion or velocity attributes.

Emitter Timing and Channels¶

• Emission Mode: chooses Continuous, Burst, or Interval emission.
• Start Frame: frame where burst emission begins.
• Duration: number of frames the burst stays active.
• Pulse: number of active frames in an interval cycle.
• Pause: number of inactive frames between interval pulses.
• Offset: shifts the interval cycle in time.
• Smoke Rate: amount of smoke emitted each frame.
• Smoke Mode: adds smoke to the current volume or sets the smoke value directly.
• Color: color tint for emitted smoke.
• Fuel Amount: amount of combustible fuel emitted each frame.
• Fuel Mode: adds fuel or sets fuel directly.
• Flame Amount: emits visible flame directly without waiting for combustion.
• Heat Amount: emitted heat. Higher values make smoke rise and help fuel ignite.
• Heat Mode: adds heat or sets heat directly.
• Initial Velocity: launch direction and speed for new smoke.
• Velocity Mode: controls how Initial Velocity enters affected voxels. Set replaces their emitted velocity immediately. Add adds velocity over time. Pull moves the current value toward Initial Velocity instead of replacing it.
• Velocity Pull: rate used by Add and Pull. Higher values apply the requested change more strongly; 0 disables the gradual Add or Pull contribution. It is hidden when Velocity Mode is Set.
• Inherit Motion: transfers movement from the source object or particles into the smoke.
• Pressure: adds outward expansion at the emitter for bursts, puffs, explosions, or pulsed effects.

Choose Set when the source must impose a specific launch vector. Use Add for continued acceleration while the source emits, or Pull when existing flow should converge toward the source velocity without being replaced in one step. Initial Velocity and inherited source motion are separate contributions, so tune Inherit Motion independently for animated objects and particle sources.

Emitter Noise¶

• Break Up Emission: uses procedural noise to vary emission density spatially.
• Emission Noise Type / Noise Type: chooses the procedural noise pattern.
• Scale: size of the noise pattern.
• Detail: number of detail layers in the noise.
• Speed: how fast the noise pattern animates.
• Strength: contrast of the noise effect.
• Seed: changes the random noise pattern.
• Break Up Velocity: adds procedural variation to the launch direction.
• Velocity Noise Type / Noise Type: chooses the velocity noise pattern.

Colliders¶

Small openings and minor defects in solid collider meshes are repaired automatically. Vertex weights follow the repaired copy. Open surface obstacles remain supported when a usable solid volume cannot be prepared.

Colliders are solid shapes that block, slow, or redirect smoke. Use them for walls, floors, moving props, and contact-driven color changes.

Collider Controls¶

• Add Collider: adds a mesh object that blocks or redirects smoke.
• Object: the mesh object that acts as the collider.
• Enabled: disables a collider without removing it.
• Automatic motion tracking: Pyro detects static, rigid T/R/S, and deforming collider motion automatically. Static geometry is cached and rigid motion reuses it with updated transforms.
• Surface Drag: how much the collider slows smoke that touches it.
• Inherit Motion: how much collider movement is carried into nearby smoke.
• Tint Smoke on Contact: turns on color transfer when smoke touches the collider.
• Color: the tint color used on contact.
• Strength: how strongly the color is blended into the smoke.
• Distance: how far from the surface the tint reaches.

Collider Weight Maps¶

Open the collider's Data Mapping > Add Mapping..., select Surface Drag, Inherit Motion or Tint Strength, then select a Map under Source: Weight Map. A map can be a vertex group or a Float attribute on the Point domain. The source shows only the Map selector; it multiplies the parameter directly without ranges, a remapping curve or Apply Mode. Use one enabled Weight Map per parameter. Clear the Map, disable or remove the mapping to restore the uniform value. Tint Strength applies when Tint Smoke on Contact is enabled.

In Lists, edit the mapping in the selected collider's settings. In Nodes, Add Mapping... creates a connected Pyro Mapping node. Choose the Map on that node. Surface Weight Map is only offered for collider targets. Both Pyro modes support these controls.

The surface weight multiplies the chosen value locally. Weight 0 removes that contribution and weight 1 uses the full value. Weights are interpolated on the evaluated mesh and clamped to 0 through 1. A zero weight does not make the collider permeable. An empty Map has no effect. A selected map name that does not exist reports an error.

Moving mapped colliders can require more processing than colliders with uniform contact settings, especially with detailed meshes. These input maps are separate from the output maps described below.

Collider Effect Maps¶

Write Effect Maps samples Pyro contact at every collider vertex after each simulated frame. The result can be written as a FLOAT geometry attribute on the mesh POINT domain or as a Blender weight map. Use these maps in Geometry Nodes, materials, modifiers, or as a Pyro surface-emission mask.

• Heat: writes the current normalized heat touching the collider.
• Burn: accumulates hot combustion contact over time, so repeated exposure grows toward 1.0.
• Flame: writes the current flame contact at the surface.
• Soot: accumulates smoke-density contact over time for persistent deposits.
• Output: chooses a Geometry Attribute or Weight Map. Geometry attributes are FLOAT values on the POINT domain.
• Map Name: names the attribute or vertex group that receives the values.
• Strength: multiplies the sampled contact before it is written or accumulated.

Heat and Flame represent the current frame; Burn and Soot persist and accumulate until the simulation is reset. Effect maps work in Sparse and Fast Dense mode. The evaluated collider must keep the same vertex count as its source mesh, and map updates pause while the object is in Edit Mode.

Disk baking stores effect-map frames beside the VDB cache and restores them during cache playback. Seamless-loop generation blends the instantaneous Heat and Flame channels and preserves the final accumulated Burn and Soot state across the loop.

Force Effects¶

Force effects are documented one by one below. Add the effect that matches the motion you want, then stack multiple forces together to shape the final look.

Shared Force Controls¶

• Add Force Effect...: opens the force menu.
• Force Type: the type of force in the selected list item.
• Enabled: disables a force without deleting it.
• Strength: how strongly the force pushes or pulls the volume. Negative values reverse directional effects; Sink absorption remains non-negative.
• Control Empty: Empty object used as a position control for localized forces.

Vortex¶

Vortex rotates the volume around a center point. Use it for tornado, ring or spiral motion.

• Control Empty: the empty that defines the vortex center. Move it to place the spin.
• Axis: the direction the vortex rotates around. Use a vertical axis for tornado-style motion.
• Strength: overall spin intensity.
• Radius: how large the spinning area is.
• Falloff: how quickly the spin fades toward the edge.
• Keep Smoke Tight: keeps strong vortices from throwing smoke outward too early.
• Pull to Axis: adds inward pull toward the center axis for tighter coils.

Wind¶

Wind is the simplest force. Use it when you want smoke to drift in one clear direction, like ambient airflow, a fan, or a directional push from off screen.

• Direction: the direction of the airflow.
• Strength: overall wind intensity.
• Mode: Force adds acceleration, Target Velocity steers toward a flow speed, and Advected offsets the scalar advection path directly.
• Acceleration: response speed used by Target Velocity.

Advected Wind applies across the whole domain in Sparse and Fast Dense. Effect masks are unavailable in this mode.

Attract¶

Attract pulls smoke toward a target point. Use it to form smoke funnels or draw smoke toward a moving Empty.

• Control Empty: the target point the smoke is pulled toward.
• Strength: how strongly the smoke is pulled in.
• Radius: how far the attraction reaches.
• Falloff: how quickly the pull fades at the edge.

Turbulence: Curl Noise¶

Curl Noise creates smooth rolling motion with low visual divergence. Use it for drifting smoke and secondary breakup.

• Control Empty: the center point of the turbulence field.
• Strength: how much motion the turbulence adds.
• Noise Size: the overall scale of the noise pattern.
• Speed: how fast the pattern animates.
• Seed: changes the random look of the motion.
• Radius: the area affected by the turbulence.
• Falloff: how softly the field fades outward.

Turbulence: FBM Noise¶

FBM turbulence combines several noise scales to add multi-scale motion detail without changing the base domain setup.

• Control Empty: the center point of the turbulence field.
• Strength: overall turbulence intensity.
• Noise Size: base scale of the motion pattern.
• Speed: animation speed of the turbulence.
• Seed: randomizes the pattern look.
• Radius: the area affected by the turbulence.
• Falloff: how quickly the effect fades at the edge.
• Detail Layers: number of stacked noise layers. More layers add higher-frequency motion detail.
• Layer Spacing: spacing between the noise layers. Larger values separate the motion more clearly.
• Layer Strength: how strongly the extra layers contribute to the final motion.

Turbulence: Simplex Noise¶

Simplex turbulence gives a clean, smooth noise motion with a lightweight feel. It is a good general-purpose choice for animated breakup and subtle drifting motion.

• Control Empty: the center point of the turbulence field.
• Strength: how strongly the smoke is pushed around.
• Noise Size: the scale of the pattern.
• Speed: how quickly the noise animates.
• Seed: creates a different random variation.
• Radius: the local area of influence.
• Falloff: how the influence fades toward the edge.

Turbulence: Classic¶

Classic turbulence is the broader layered-noise version of the turbulence force. Use it when you want structured motion that still feels soft and natural.

• Control Empty: the center point of the turbulence field.
• Strength: overall motion strength.
• Noise Size: scale of the motion pattern.
• Speed: animation speed of the field.
• Seed: randomizes the pattern.
• Radius: how far the turbulence reaches.
• Falloff: how quickly the force fades out.
• Detail Layers: how many layers are used to build the motion.
• Layer Spacing: distance between the layered noise bands.
• Layer Strength: how much each extra layer contributes.

Turbulence: Wavy¶

Wavy turbulence adds rhythmic, wave-like motion for repeated directional distortion.

• Control Empty: the center point of the turbulence field.
• Strength: the amount of motion added to the smoke.
• Noise Size: the scale of the wave pattern.
• Speed: how fast the waves animate.
• Seed: changes the pattern variation.
• Radius: the area affected by the effect.
• Falloff: how the influence fades near the edge.

Turbulence: Voronoise¶

Voronoise turbulence produces cell-like breakup. Use it when the motion should separate into more distinct regions.

• Control Empty: the center point of the turbulence field.
• Strength: how strongly the smoke is perturbed.
• Noise Size: the size of the cell pattern.
• Speed: animation speed of the pattern.
• Seed: randomizes the pattern layout.
• Radius: the affected area around the center.
• Falloff: how quickly the effect fades away.

Turbulence: Cubic Noise¶

Cubic turbulence creates a soft, rounded noise response. It is a good choice when you want gentle motion without sharp noise edges.

• Control Empty: the center point of the turbulence field.
• Strength: the amount of motion added to the smoke.
• Noise Size: the scale of the turbulence pattern.
• Speed: how quickly the motion changes.
• Seed: randomizes the noise variation.
• Radius: the local size of the effect.
• Falloff: how soft the edge of the effect is.

Follow Curve¶

Follow Curve guides the volume along a Blender curve for ribbon-like smoke, spirals, or other controlled paths.

• Curve: the curve object that defines the path.
• Strength: how strongly the curve influences the smoke.
• Attract: blends between flowing along the curve and being pulled toward it.
• Invert: reverses the flow direction.
• Sample Points: how many points are used to build the curve guide.
• Radius: how far from the curve the guidance reaches.
• Falloff: how quickly the curve influence fades away.

Multiple Follow Curve effects can be active at the same time. Each effect keeps its own sampled point range and cyclic state in both solver modes.

Sink¶

Sink removes transported Pyro fields inside a bounded Box or Sphere. Use it for drains, extraction volumes, open-looking vents, or art-directed removal that should not depend on a domain face.

• Control Empty: positions the sink. Its evaluated scale and display size define the volume; without the Empty, the Sink is skipped.
• Shape: Box uses the Empty's independent XYZ extents. Sphere uses an averaged radius from those extents.
• Falloff: softens the Sink response toward the boundary.
• Absorption: rate at which smoke, temperature, fuel, flame and color fade toward zero inside the volume. It is non-negative.
• Velocity Damping: separately removes velocity inside the Sink. Keep it near zero for an outlet where flow should continue through the disappearing scalar fields; raise it for an absorber volume that should also calm motion.

Absorption and Velocity Damping are separate Pyro Data Mapping targets. Mapping them can make removal depend on a supported emitter or grid source without changing the Sink's geometric boundary.

Effect Masking¶

• Affect Where: chooses where the selected force is allowed to act.
• Start / End: boundaries for gradient-style masks.
• Min / Max: lower and upper limits for value-based masks.
• Contrast: sharpness of the mask transition.
• Invert: reverses the mask.
• Mask Empty: Empty object that controls a spherical mask.
• Velocity Direction: affects smoke moving in a chosen direction.
• Noise Type, Noise Scale, Detail, and Speed: controls for noise-based force masks.