Composites & Objects

This section covers both the low-level Composite class and the high-level helper functions and React components used to create common shapes.

The Composite Class

A Composite is a container for a group of Particle and Constraint objects. It is the primary way to group objects in the simulation.

Properties

• particles (Particle[]): An array of particles in the composite.
• constraints (Constraint[]): An array of constraints in the composite.

Methods

• pin(index, [pos]): A convenience method to create a PinConstraint for a particle within the composite.

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High-Level Objects

These are helpers that create and add pre-made composites to the simulation.

Line Segments

Creates a chain of particles connected by distance constraints.

lineSegments()

lineSegments(sim, vertices, stiffness)

• sim (VerletJS): The simulation instance.
• vertices (Vec2[]): An array of points for the line.
• stiffness (number): The stiffness of the constraints.

<LineSegments />

• vertices (Vec2[]): An array of points for the line.
• stiffness (number): The stiffness of the constraints.
• pins (number[], optional): An array of particle indices to pin.

Cloth

Creates a 2D grid of particles, ideal for fabric simulations.

cloth()

cloth(sim, origin, width, height, segmentsX, segmentsY, pinMod, stiffness)

• sim (VerletJS): The simulation instance.
• origin (Vec2): The center point of the cloth.
• width / height (number): The dimensions of the cloth.
• segmentsX / segmentsY (number): The number of segments on each axis.
• pinMod (number): A modifier for pinning particles on the top edge (e.g., 3 pins every 3rd particle).
• stiffness (number): The stiffness of the constraints.

<Cloth />

• origin (Vec2): The center point of the cloth.
• width / height (number): The dimensions of the cloth.
• segmentsX / segmentsY (number): The number of segments on each axis.
• pinMod (number): A modifier for pinning particles.
• stiffness (number): The stiffness of the constraints.

Tire

Creates a circular object with spokes.

tire()

tire(sim, origin, radius, segments, spokeStiffness, treadStiffness)

• sim (VerletJS): The simulation instance.
• origin (Vec2): The center of the tire.
• radius (number): The radius of the tire.
• segments (number): The number of segments.
• spokeStiffness (number): The stiffness of the spokes connecting to the center.
• treadStiffness (number): The stiffness of the outer tread.

<Tire />

• origin (Vec2): The center of the tire.
• radius (number): The radius of the tire.
• segments (number): The number of segments.
• spokeStiffness (number): The stiffness of the spokes.
• treadStiffness (number): The stiffness of the outer tread.