VfxPrimitiveBeam

Inheritance 3 ancestors · 9 siblings

• VfxPrimitiveBase
  • VfxLegacyPrimitiveBase&IVfxShimmerGeometry
    • VfxPrimitiveArbitraryQuad
    • VfxPrimitiveBeamcurrent
    • VfxPrimitiveBeamBase1
    • VfxPrimitiveCameraQuad1
    • VfxPrimitiveMeshBase2
    • VfxPrimitiveNonRenderable
    • VfxPrimitiveProjectionBase1
    • VfxPrimitiveRay
    • VfxPrimitiveTrailBase2
    • VfxShimmerPrimitiveBase8

Class Documentation

Edit documentation

A straight beam: one quad per particle, stretched between two endpoints that belong to the system rather than to the particle.

Endpoints. Both ends are computed from the running system every frame:

• Source: the system's current world position, plus mLocalSpaceSourceOffset rotated into the system's orientation
• Target: the target position of the effect instance, plus mLocalSpaceTargetOffset rotated the same way

The offsets are documented on VfxBeamBaseDefinitionData.

The particle's position does not place either end, so every particle of the emitter draws the same segment. Particles differ only in width, color and texture tiling, and they draw stacked on each other. More particles add more coincident quads, not a longer or a divided beam.

Width. scale.x is the full width. Which way it points is set by mBeam.mMode: facing the camera, or lying flat along the world's horizontal plane. See VfxBeamDefinitionData.mMode.

Length. scale.y and scale.z trim the two ends, as fractions of the beam:

sourceEdge = source + (target - source) · scale.y
targetEdge = target - (target - source) · scale.z

With both at 0, or both at 1, the quad covers the whole beam. Values in between move each edge toward the other end.

Texture. The texture's v axis lies along the beam and its u axis across it. The emitter's UV transform is applied with its first axis along the beam, so a u scroll such as BirthUvScrollRate.x moves the texture along the beam. The number of repeats comes from mBeam.mBirthTilingSize: width / x across and length / y along, where a component of 0 or below gives one repeat. The length is the full distance between the endpoints even when the quad is trimmed, so trimming shortens the quad without removing repeats.

Properties

mBeam

Embed<VfxBeamDefinitionData>

Default value

{
  "mSegments": 0,
  "mTrailMode": 0,
  "mBirthTilingSize": { "constantValue": [0, 0, 0], "dynamics": null },
  "mIsColorBindedWithDistance": false,
  "mMode": 0,
  "mAnimatedColorWithDistance": { "constantValue": [1, 1, 1, 1], "dynamics": null },
  "mLocalSpaceTargetOffset": [0, 0, 0],
  "mLocalSpaceSourceOffset": [0, 0, 0]
}

Documentation Edit documentation

The beam's settings: its width mode, texture tiling, color by distance and endpoint offsets. See VfxBeamDefinitionData.

mMesh

Embed<VfxMeshDefinitionData>

Default value

{
  "mAnimationVariants": [],
  "mMeshName": "",
  "mMeshSkeletonName": "",
  "mSubmeshesToDrawAlways": [],
  "mSimpleMeshName": "",
  "mSubmeshesToDraw": [],
  "mLockMeshToAttachment": false,
  "mAnimationName": ""
}

Documentation Edit documentation

A mesh to draw in place of the quad. When any mesh named here loads, the quad is not drawn and the emitter's particles draw the mesh instead, turned to lie along the line between the two endpoints, with world up as its up axis (world X for a vertical beam). How the mesh is placed and scaled along the beam is not yet identified. See VfxMeshDefinitionData for how the mesh is chosen.

mBeam

mMesh