The shader bit that turns each particle's four vertices into a camera-facing quad
The geometry repeats each particle's centre in aPosition (float32x3) on all four vertices,
and gives each vertex its corner, (0, 0) to (1, 1), in aUV (unorm8x2). The bit declares
aParticleSizeRot (float32x2), aParticleColor (unorm8x4) and, with frames,
aParticleUVFrame (unorm16x4); ParticleBuiltInValues says what each holds.
A bit composed after it can grow, spin or recolour a particle by assigning the vertex-stage
locals particleSize, particleRotation and particleColor in its beforeTransform.
particleColor is in display space, so a colour ramp blends as a 2D tween does.
The shader bit that turns each particle's four vertices into a camera-facing quad
The geometry repeats each particle's centre in
aPosition(float32x3) on all four vertices, and gives each vertex its corner,(0, 0)to(1, 1), inaUV(unorm8x2). The bit declaresaParticleSizeRot(float32x2),aParticleColor(unorm8x4) and, withframes,aParticleUVFrame(unorm16x4); ParticleBuiltInValues says what each holds.A bit composed after it can grow, spin or recolour a particle by assigning the vertex-stage locals
particleSize,particleRotationandparticleColorin itsbeforeTransform.particleColoris in display space, so a colour ramp blends as a 2D tween does.