playcanvas/build/playcanvas/src/framework/components/rigid-body/contact-point.d.ts

Open-source WebGL/WebGPU 3D engine for the web

/**
 * Represents a single point of contact between two colliding rigid bodies in the physics
 * simulation. Each contact point stores detailed spatial information about the collision,
 * including both local and world space coordinates of the exact contact points on both entities,
 * the contact normal direction, and the collision impulse force.
 *
 * Contact points are generated by the physics engine during collision detection and are typically
 * accessed through a {@link ContactResult} object, which can contain multiple contact points for a
 * single collision between two entities. Multiple contact points commonly occur when objects
 * collide along edges or faces rather than at a single point.
 *
 * The impulse property can be particularly useful for gameplay mechanics that need to respond
 * differently based on the force of impact, such as damage calculations or sound effect volume.
 *
 * @example
 * // Access contact points from a collision event
 * entity.collision.on('contact', (result) => {
 *     // Get the first contact point
 *     const contact = result.contacts[0];
 *
 *     // Get the contact position in world space
 *     const worldPos = contact.point;
 *
 *     // Check how hard the collision was
 *     if (contact.impulse > 10) {
 *         console.log("That was a hard impact!");
 *     }
 * });
 *
 * @category Physics
 */
export class ContactPoint {
    /**
     * Create a new ContactPoint instance.
     *
     * @param {Vec3} [localPoint] - The point on the entity where the contact occurred, relative to
     * the entity.
     * @param {Vec3} [localPointOther] - The point on the other entity where the contact occurred,
     * relative to the other entity.
     * @param {Vec3} [point] - The point on the entity where the contact occurred, in world space.
     * @param {Vec3} [pointOther] - The point on the other entity where the contact occurred, in
     * world space.
     * @param {Vec3} [normal] - The normal vector of the contact on the other entity, in world
     * space.
     * @param {number} [impulse] - The total accumulated impulse applied by the constraint solver
     * during the last sub-step. Describes how hard two objects collide. Defaults to 0.
     * @ignore
     */
    constructor(localPoint?: Vec3, localPointOther?: Vec3, point?: Vec3, pointOther?: Vec3, normal?: Vec3, impulse?: number);
    /**
     * The point on the entity where the contact occurred, relative to the entity.
     *
     * @type {Vec3}
     */
    localPoint: Vec3;
    /**
     * The point on the other entity where the contact occurred, relative to the other entity.
     *
     * @type {Vec3}
     */
    localPointOther: Vec3;
    /**
     * The point on the entity where the contact occurred, in world space.
     *
     * @type {Vec3}
     */
    point: Vec3;
    /**
     * The point on the other entity where the contact occurred, in world space.
     *
     * @type {Vec3}
     */
    pointOther: Vec3;
    /**
     * The normal vector of the contact on the other entity, in world space. This vector points
     * away from the surface of the other entity at the point of contact.
     *
     * @type {Vec3}
     */
    normal: Vec3;
    /**
     * The total accumulated impulse applied by the constraint solver during the last sub-step.
     * This value represents how hard two objects collided. Higher values indicate stronger impacts.
     *
     * @type {number}
     */
    impulse: number;
}
import { Vec3 } from '../../../core/math/vec3.js';