getBoundingSphereAt method

dynamic getBoundingSphereAt(dynamic id, dynamic target)

Implementation

getBoundingSphereAt( id, target ) {
	final active = _active;
	if ( active[ id ] == false ) {
		return null;
	}

	// compute bounding sphere
	final bound = _bounds[ id ];
	final sphere = bound.sphere;
	final geometry = this.geometry;
	if ( bound.sphereInitialized == false ) {

		sphere.empty();

		getBoundingBoxAt( id, _box );
		_box.getCenter( sphere.center );

		final index = geometry?.index;
		final position = geometry?.attributes['position'];
		final drawRange = _drawRanges[ id ];

		double maxRadiusSq = 0;
		for (int i = drawRange.start, l = drawRange.start + drawRange.count; i < l; i ++ ) {
			int iv = i;
			if ( index != null) {
				iv = index.getX(iv)!.toInt();
			}

			_vector.fromBuffer( position, iv );
			maxRadiusSq = math.max( maxRadiusSq, sphere.center.distanceToSquared( _vector ) );
		}

		sphere.radius = math.sqrt( maxRadiusSq );
		bound.sphereInitialized = true;
	}

	target.copy( sphere );
	return target;
}