scene_queries_point_projection

Point projection will either project a point on the closest collider of the scene (RapierContext::project_point), or will enumerate every collider containing given point (RapierContext::intersect_point).

Example 2D

/* Project a point inside of a system. */
fn project_point(rapier_context: ReadRapierContext) {
    let rapier_context = rapier_context.single().unwrap();
    let point = Vec2::new(1.0, 2.0);
    let max_dist = 4.0; // Colliders further than this distance are ignored.
    let solid = true;
    let filter = QueryFilter::default();

    if let Some((entity, projection)) = rapier_context.project_point(point, max_dist, solid, filter)
    {
        // The collider closest to the point is attached to `entity`.
        println!(
            "Projected point on entity {:?}. Point projection: {}",
            entity, projection.point
        );
        println!(
            "Point was inside of the collider shape: {}",
            projection.is_inside
        );
    }

    rapier_context.intersect_point(point, filter, |entity, _collider| {
        // Callback called on each collider with a shape containing the point.
        println!("The entity {:?} contains the point.", entity);
        // Return `false` instead if we want to stop searching for other colliders containing this point.
        true
    });
}

Example 3D

/* Project a point inside of a system. */
fn project_point(rapier_context: ReadRapierContext) {
    let rapier_context = rapier_context.single().unwrap();
    let point = Vec3::new(1.0, 2.0, 3.0);
    let max_dist = 4.0; // Colliders further than this distance are ignored.
    let solid = true;
    let filter = QueryFilter::default();

    if let Some((entity, projection)) = rapier_context.project_point(point, max_dist, solid, filter)
    {
        // The collider closest to the point is attached to `entity`.
        println!(
            "Projected point on entity {:?}. Point projection: {}",
            entity, projection.point
        );
        println!(
            "Point was inside of the collider shape: {}",
            projection.is_inside
        );
    }

    rapier_context.intersect_point(point, filter, |entity, _collider| {
        // Callback called on each collider with a shape containing the point.
        println!("The entity {:?} contains the point.", entity);
        // Return `false` instead if we want to stop searching for other colliders containing this point.
        true
    });
}

The resulting PointProjection also contains the index of the part of the shape the point was projected on (subshape) for shapes composed of several pieces (compound shapes, triangle meshes, etc.) Just like for ray-casting, the closure given to RapierContext::intersect_point is given the entity of each collider containing the point, as well as its Rapier collider, and can return false to stop the search.

It is possible to only apply the scene query to a subsets of the colliders using a query filter