Shape cast

Shape casting groups different features related to using Physics V2 shapes to make queries in the physics world. In short, use physics shapes to query collisions and distances to other physics shapes. This API is specific to the Havok plugin.

Common query interface

These two properties are common to all query interfaces:

/**
 * Should trigger collisions be considered in the query?
 */
shouldHitTriggers: boolean;
/**
 * Should the query ignore the body that is passed in?
 */
ignoreBody?: PhysicsBody;

Point Proximity Query

Query the closest shape within a maxDistance radius.

export interface IPhysicsPointProximityQuery {
/**
* The position of the query
*/
position: Vector3;
/**
* Maximum distance to check for collisions. Can be set to 0 to check for overlaps.
*/
maxDistance: number;
/**
* Collision filter for the query.
*/
collisionFilter: IRaycastQuery;
}

Use this interface to do the query:

import { HavokPlugin } from "@babylonjs/core/Physics/v2/Plugins/havokPlugin";
var hk = new HavokPlugin();
hk.pointProximity({
    position: ballPos,
    maxDistance: 0.1
}, result);

See below for the result definition.

PG: Point Proximity

Shape Proximity Query

Instead of a point, provide a shape. The interface becomes:

hk.shapeProximity(
    {
        shape: shape1,
        position: mesh1.absolutePosition,
        rotation: mesh1.absoluteRotationQuaternion,
        maxDistance: 10
    },
    shapeLocalResult,
    hitWorldResult
);

Two results are returned: the first one is local to the shape. The second is in world space.

PG: Shape Proximity

Shape Cast query

When a shape moves from a start position to an end position, this query tells you at what fraction of that movement a collision occurs.

Note: The result will not be correct for intersecting shapes.

hk.shapeCast({
    shape: shape1,
    rotation: mesh1.rotationQuaternion,
    startPosition: castStartPosition,
    endPosition: castEndPosition,
    shouldHitTriggers: false,
}, shapeLocalResult, hitWorldResult);

For a positioned and oriented shape moving from startPosition to endPosition, shapeLocalResult and hitWorldResult—both of type ShapeCastResult—will have the hasHit property set to true when a collision occurs. Then, get the fraction of that movement with the hitFraction property.

PG: Shape Cast

Queries result

Result information for these three queries is contained in:

• ProximityCastResult for proximity and shape proximity
• ShapeCastResult for shape cast

export class CastingResult {
    /**
     * The Physics body that the query hit.
     */
    public body?: PhysicsBody;
    /**
     * The body Index in case the Physics body is using instances
     */
    public bodyIndex?: number;

    /**
     * The shape hit by the query.
     */
    public shape?: PhysicsShape;
    ...

Raycast results also inherit from this base class.

The ProximityCastResult-specific property is:

/**
 * Gets the distance from the hit
 */
hitDistance: number;

The ShapeCastResult-specific property is:

/**
 * Gets the hit fraction along the casting ray
 */
hitFraction: number