Effects guides
Render Multiply
Many times the particles at render time, for the cost of a small bake: copies scattered round each particle that move with it. For sparks, dust, snow and spray.
VecFlow 0.1.0
Render Multiply shows each particle as several: itself and copies scattered round it, moving with it. A bake of 50,000 particles renders as half a million. The copies are made as Blender shows the frame, not baked, so they cost no bake time, and change live.
When it fits, and when it doesn't
The copies have no physics: they don't collide with anything or push anything. They follow their particle.
- Fits: sparks, dust, snow, spray, mist, embers, magic, confetti in the air. Anything loose, where more of it reads as detail.
- Doesn't: sand, rigid bodies, liquid, piles, anything resting on the ground or touching. Copies go through floors and walls.
Settings
In the sidebar's Display panel, turn on Render Multiply:
| Setting | What it does |
|---|---|
| Copies | How many each particle shows as, itself included |
| Spread | How far from its particle a copy can be; most are nearer in. Keep it small near floors and walls |
| Copy Size | The copies' size, to their particle's, each a little smaller still at random |
| Drift | How fast the copies wander round their particle. 0 holds each where it is |
| In Viewport | Shows the copies in the viewport too, not only in renders. Slower |
In a shader
Copies carry two attributes of their own:
vf_copy: 1 on the copies, 0 on the particles themselves, to give the copies a look of their own;vf_shrink: how much smaller a copy is than its particle.
Each copy has an id of its own too, so a White Noise from id gives each
copy its own random look.
What goes wrong
- Copies poke through the floor. Lower Spread, or don't use it on particles that rest on something.
- The cloud looks lumpy, in clusters. Spread is too small for the gap between particles: raise it, or bake more particles and use fewer copies.
- Renders are slow. Fewer Copies.
- The viewport is slow. Turn In Viewport off: the copies then show only in renders.