What VecFlow is

VecFlow makes particle effects in Blender. Particles are born from an object, pushed by forces, bounce off other objects, and change as things happen to them: a drop that hits the ground can turn red and burst into smaller bits.

The same engine does much more than loose particles:

• Particles: sparks, dust, magic, snow, rain and confetti, as points, spheres or any shape you model.
• Grains that bump into each other and pile up, like sand.
• Flocks of birds or schools of fish that steer round each other.
• Cloth, ropes and soft bodies, made from a mesh's vertices held together.
• Rigid bodies that tumble and stack, joined by hinges and sliders, and meshes shattered into pieces that break apart.
• Liquids with a surface mesh to render, and whitewater: spray, foam and bubbles.
• Smoke and fire, as a volume to render.

How it worksCopy Anchor Link

You set a simulation up in Blender, then bake it: VecFlow works out every frame of the scene's frame range and writes each one to a file on disk. Blender then plays those files back. Scrubbing the timeline is instant, and a render shows exactly what you saw in the viewport.

A bake gives the same result every time, on any computer, on the CPU or on an NVIDIA graphics card. A bake on a GPU is just faster. (The one exception is NVIDIA Flow, a second smoke solver you can pick: its results depend on the card.)

The words used in this guideCopy Anchor Link

• Particles object: The object that holds a simulation. Its settings live in the VecFlow tab of the 3D Viewport's sidebar, and it shows the bake: points, spheres or shapes. Select it (or its emitter) to see its settings.

• Emitter: The object particles are born from: an Empty (they come from its box) or a mesh (from its surface or its inside). It can move.

• Simple settings: A particles object with no flow is set up by the sidebar's own panels: Emission, Forces, Collisions, and Size, Spin and Colour. That covers a stream of particles with forces and colliders.

• Flow: For anything more, a particles object can follow a flow instead: a node tree made in the node editor. A flow is made of events, and each event holds a stack of operators that act on the particles in it, top to bottom, every step. Some operators send particles on to another event along a wire: drops that hit the ground go to a "Splash" event, which colours them and spawns bits.

• Bake: Working out the simulation and writing it to disk. Pressing Bake does it for the scene's frame range. See How a bake works.

• Cache folder: Where the bake's files go: a folder called vecflow_cache next to your .blend file, unless you pick another. See The cache folder.

• Starter: A ready-made simulation, made with one click: fire, smoke, a dam break, confetti, a shattering mesh. Each is an ordinary particles object you can change. See Starters.

Where to go nextCopy Anchor Link