VfxPhysicsVelocityModifier

Inheritance 1 ancestor · 14 siblings

• VfxPhysicsModifierBase
  • 0x402b2a8f
  • 0x4a2445d4
  • 0x8edc8e76
  • 0xc685a3b6
  • VfxPhysicsAccelerationModifier
  • VfxPhysicsDragModifier
  • VfxPhysicsFollowTerrainModifier
  • VfxPhysicsGroundCollisionModifier
  • VfxPhysicsOrbitModifier
  • VfxPhysicsPositionModifier
  • VfxPhysicsRotationModifier
  • VfxPhysicsScaleModifier
  • VfxPhysicsSimpleModifier (removed in patch 16.13)
  • VfxPhysicsVelocityModifiercurrent
  • VfxPhysicsWorldSpaceTranslationModifier (removed in patch 15.24)

Class Documentation

Edit documentation

A physics modifier that moves the particles at a velocity. On each step, before the integration, the velocity is the sum of three parts:

• local: InitialLocalVelocity * KeyedLocalVelocity, in the axes of the particle's reference frame;
• world: InitialWorldVelocity * KeyedWorldVelocity, which keeps its world direction;
• radial: InitialRadialVelocity along the radial direction (see RadialOriginOffset).

The particle is moved by velocity * dt as a displacement. This velocity is not added to the particle's own velocity, so it stops acting when its keyed value drops to zero, and accelerations do not add to it. Units are world units per second.

Drag. With a VfxPhysicsDragModifier in the list, the drag takes away part of this velocity on every step: a fraction drag * dt, clamped to [0, 1], of what is left is absorbed and stays absorbed. The particle slows down even when the keyed values stay constant.

Notes

• Some shipped component emitters use it, with a constant InitialLocalVelocity.

Properties

0xa216ab25

Flag = false

Removed in 15.24

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0xf65597d8

Flag = false

Removed in 15.24

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0xfd3fee0f

Flag = false

Removed in 15.24

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EmissionSource

Pointer<IVfxEmissionSource> = null

Removed in 16.1 15.24

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InitialLocalOffset

Embed<VfxVector3DynamicProperty> = { "Vector3": {} }

Removed in 16.1 15.24

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InitialLocalVelocity

Embed<VfxVector3DynamicProperty> = { "Vector3": {} }

Type history (2 revisions)

• 15.23 - 15.23 Embed<ValueVector3>
• since 15.24 Embed<VfxVector3DynamicProperty>

Documentation Edit documentation

Local velocity, evaluated once per particle at spawn.

InitialRadialVelocity

Embed<VfxFloatDynamicProperty> = { "Float": {} }

Type history (2 revisions)

• 15.23 - 15.23 Embed<ValueFloat>
• since 15.24 Embed<VfxFloatDynamicProperty>

Documentation Edit documentation

Speed along the radial direction, as a float driver value evaluated once per particle at spawn. A positive value moves the particle away from the radial origin.

InitialWorldVelocity

Embed<VfxVector3DynamicProperty> = { "Vector3": {} }

Type history (2 revisions)

• 15.23 - 15.23 Embed<ValueVector3>
• since 15.24 Embed<VfxVector3DynamicProperty>

Documentation Edit documentation

World velocity, evaluated once per particle at spawn.

KeyedLocalVelocity

Embed<VfxVector3DynamicProperty> = { "Vector3": {} }

Type history (2 revisions)

• 15.23 - 15.23 Embed<ValueVector3>
• since 15.24 Embed<VfxVector3DynamicProperty>

Documentation Edit documentation

Multiplier on InitialLocalVelocity, evaluated on every step.

KeyedRadialVelocity

Embed<VfxFloatDynamicProperty> = { "Float": {} }

Type history (2 revisions)

• 15.23 - 15.23 Embed<ValueFloat>
• since 15.24 Embed<VfxFloatDynamicProperty>

Documentation Edit documentation

Expected to multiply InitialRadialVelocity on every step, in the way of the other Keyed values. This is not confirmed.

KeyedWorldVelocity

Embed<VfxVector3DynamicProperty> = { "Vector3": {} }

Type history (2 revisions)

• 15.23 - 15.23 Embed<ValueVector3>
• since 15.24 Embed<VfxVector3DynamicProperty>

Documentation Edit documentation

Multiplier on InitialWorldVelocity, evaluated on every step.

RadialOriginOffset

Embed<VfxVector3DynamicProperty> = { "Vector3": null }

16.6

Documentation Edit documentation

The point that the radial direction points away from, in the particle's reference frame. The direction depends on whether the particle has an emission normal from a VfxPhysicsPositionModifier with an EmissionSource:

Emission normal	RadialOriginOffset	Radial direction
no	unset	From the frame origin to the particle.
no	set	From this point to the particle.
yes	unset	The emission normal.
yes	set	From this point to the particle's emission point. If the two coincide, the emission normal.

0xa216ab25

0xf65597d8

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EmissionSource

InitialLocalOffset

InitialLocalVelocity

InitialRadialVelocity

InitialWorldVelocity

KeyedLocalVelocity

KeyedRadialVelocity

KeyedWorldVelocity

RadialOriginOffset