pTangent Force Node

For each particle, pTangent Force computes the vector from the particle to the center, then applies a force at 90° to that vector. This produces pure rotation with no radial movement.

Perfect for simulating stable orbits, spinning swarms and spiral galaxies without central suction. Combine it with pPoint Force if you want to add controllable attraction.

• Effects Library: Tools > Particles > pTangent Force
• Quick add: right-click in the Node Editor → Add Tool > Particles > pTangent Force

pTangent Force

Pure rotation. Constant radial distance. Stable orbits.

pVortex

Rotation + central attraction. A converging spiral.

Rule: orbit without suction → pTangent Force. Spiral suction → pVortex. Separate control → pTangent Force + pPoint Force, adjustable independently.

• Particle Input (orange) - incoming stream.
• Region Input (green/magenta) - optional. Area of influence (bitmap/mesh).

Stable orbit around a point:
pEmitter → pTangent Force (Strength Y) → pRender
(particles spin around the Y axis)

Spinning swarm:
pEmitter → pTangent Force (gentle rotation)
         → pPoint Force (weak attraction) → pRender
(orbits slowly converging toward the center)

Stable galaxy:
pEmitter (disc of particles) → pTangent Force (dominant Y)
                                → pRender
(a galaxy that spins without imploding)

Position X / Y / Z (default: 0, 0, 0)

Center the particles spin around.

Strength X / Y / Z

Intensity of the tangential force per axis. Dominant Strength Y = rotation in the XZ plane (horizontal, a galaxy seen from above). Dominant Strength X = rotation in the YZ plane (a vertical wheel).

Randomize

Seed for individual variations.

Conditions (Sets)

Force applied only to certain sets.

• Planetary orbits - particles at a given distance from the center + pTangent Force = stable orbital rotation (planets, satellites).
• Stable galaxy - a disc of particles + pTangent = a spiral that spins without imploding (unlike pVortex).
• Whirlwind without suction - leaves swirling without being sucked toward a center.
• Orbital swarm - combined with a weak pPoint Force = a swarm spinning around a point with moderate attraction.
• Ring system (Saturn's rings) - particles in a disc + pTangent Force = a spinning planetary ring.
• Magic circle - glowing particles spinning in a circle = magic rituals, mystic portals.

• Strength Y for horizontal rotation (XZ plane), Strength X for vertical rotation (YZ plane). Combine them for oblique orbits.
• Combine with pPoint Force for decomposed orbits: pPoint Force controls the distance, pTangent Force controls the angular speed. A more flexible physical model than a pVortex.
• Uniform angular speed - at a constant Strength, distant particles spin more slowly (longer orbital period). That is physically realistic.
• An alternative to pVortex - when you want to control rotation and attraction separately, pTangent Force + pPoint Force > pVortex (which combines them).
• For a natural swarm, combine it with pTurbulence = undulating orbits.