Particle Documentation - Particle Motion Collision component

This component enables collisions between the terrain and the particle. Collision detection in Minecraft consists of detecting an intersection, moving to a nearby non-intersecting point for the particle (if possible), and setting its direction to not be aimed towards the collision (usually perpendicular to the collision surface).

Important

If this component doesn't exist, there will be no collision.

"minecraft:particle_motion_collision": {
    // enables collision when true/non-zero.
    // evaluated every frame
    "enabled": <bool/molang> <default:true>

    // alters the speed of the particle when it has collided
    // useful for emulating friction/drag when colliding, e.g a particle
    // that hits the ground would slow to a stop.
    // This drag slows down the particle by this amount in blocks/sec
    // when in contact
    "collision_drag": <float>

    // used for bouncing/not-bouncing
    // Set to 0.0 to not bounce, 1.0 to bounce back up to original hight
    // and in-between to lose speed after bouncing.  Set to >1.0 to gain energy on each bounce
    "coefficient_of_restitution": <float>

    // used to minimize interpenetration of particles with the environment
    // note that this must be less than or equal to 1/2 block
    "collision_radius": <float>

    // triggers expiration on contact if true
    "expire_on_contact": <bool>

    // triggers an event
    // array of individual events
    "events": [
        {
          // triggers the specified event if the conditions are met
          "event": <string>
          // optional minimum speed for event triggering
          "min_speed": <float> // default/minimum is 2 blocks/sec
        },
    ],
    "events": { // can be an individual event as well
        // triggers the specified event if the conditions are met
        "event": <string>
        // optional minimum speed for event triggering
        "min_speed": <float> // default/minimum is 2 blocks/sec
    }
}