VecFlow0.1.0
FlowsOperators

Group Test

Send particles born on a mesh's vertices on to another event by a vertex group: hang cloth by its corners, pin a rope's end.

VecFlow 0.1.0

Particles born on an object's vertices go along the wire where the vertex weighs more than a value in a vertex group: say to an event with Pin, to hang cloth by its corners.

Add it
EventAdd OperatorTestsGroup Test
Sends on
Along its wire: particles whose vertex weighs more than the weight.
Influence
Yes: it works only on particles whose value is above a half.

When to use it

For particles born on a mesh's vertices (Birth On Vertices), to pick some out by a vertex group: a flag's edge to hold on its pole, a curtain's top, the ends of a rope, the corners of a sheet. Send them to an event with a Pin, and the rest hang from them.

Set it up

On the mesh, make a vertex group with the vertices to hold, at weight 1: in Edit Mode, select them, then Object Data Properties ▸ Vertex Groups ▸ + ▸ Assign.

In the event with the Birth On Vertices, add Add OperatorTestsGroup Test. Name the mesh in Object and the group in Vertex Group.

Wire it to an event with a Pin: Hold Still, or moving with an object.

A flow of 2 events. Cloth: Birth, Group Test, Gravity, Drag, Bind, Collide; Group Test: 'pole side' above 0.5 sends to Held. Held: Pin.ClothGroup Test: 'pole side' above 0.5Bind: mesh edges, bend 0.3Collide: PoleBirth: on Flag's vertices at frame 1. Make new particles: some every frame, all at once, one on each vertex of an object's mesh (for cloth and ropes: bind them with Bind, Mesh Edges), one on each piece of it (to smash: glue them with Bind, Pieces), or the event's Liquid filling itBirth: on Flag's vertices at fra…Group Test: 'pole side' above 0.5. Particles born on an object's vertices go along the wire where the vertex weighs more than a value in a vertex group: say to an event with Pin, to hang cloth by its cornersGroup Test: 'pole side' above 0.5Gravity: 9.81 m/s². Pull particles down, or any way you point itGravity: 9.81 m/s²Drag: 0.15, wind. Slow particles to the speed of the air, which moves with the windDrag: 0.15, windBind: mesh edges, bend 0.3. Hold particles together: soft bodies, ropes, cloth, sticky goo, things that tear. Binds hold wherever the particles go, until they break. Rigid bodies they hold turn on joints: chains, doors, ropes with crates. Particles losing a bind go along the wireBind: mesh edges, bend 0.3Collide: Pole. Bounce off an object, a collection's objects or the ground, friction slowing their sliding and their spin where they touch. The ones that hit go along the wireCollide: PoleInHeldPin: with Pole. Hold particles still, or move them with an object. Bound and bumping particles give way to them. Kinematic rigid bodies move and turn with the objectPin: with PoleIn
A flag: the vertices in its 'pole side' group go to Held, pinned to the pole; the rest of the cloth hangs from them.BirthForcesPhysicsLooksTests

Settings

As the flow editor’s sidebar shows them. Changing any of them marks the bake old; those marked Keyframable can also change through a bake.

Object
None

The object this operator works with.

Vertex Group

The object's vertex group to use.

Weight Above
Keyframable
0.50 to 1

Particles go where their vertex weighs more than this in the group.

InfluenceEmpty

One of the flow’s number values, to weigh it by, particle by particle. Empty for all of it, on all of them. See Influence.

Weight Above picks the vertices whose weight in the group is more than it: 0.5 takes those painted more than half. Weight-paint softly and move it to pick more or fewer.

Only particles born on Object's vertices are tested. Others in the event stay where they are.

The wire

Not wired, a Group Test does nothing: particles stay. It tests every step, so the particles in the group go on in the first step they're in the event, and the rest hang from them from the start.

Works with

  • Bind Mesh Edges keeps the binds between the cloth and the held particles, though they're in two events.
  • Pin, in the event it sends to.
  • Influence: weighed by a value, only particles whose value is above a half are tested.

Problems you may see

Error

event: operator needs a vertex group

Error

event: operator: 'object' has no vertex group 'group'

Errors stop a bake; warnings don’t. Every message is on the Messages page.

Chance Test

Send particles on to another event at random, so often a second on average: blinking, flickering, random breaks.

Distance Test

Send particles on to another event when they're nearer to an object, or farther from it, than a distance.

On this page

When to use itSet it upSettingsThe wireWorks withProblems you may seeRelated