updateShadowBounds method

Implementation

void updateShadowBounds() {
	final frustums = this.frustums;
	for (int i = 0; i < frustums.length; i ++ ) {

		final light = lights[ i ];
		final shadowCam = light.shadow?.camera;
		final frustum = this.frustums[ i ];

		// Get the two points that represent that furthest points on the frustum assuming
		// that's either the diagonal across the far plane or the diagonal across the whole
		// frustum itself.
		final nearVerts = frustum.vertices.near;
		final farVerts = frustum.vertices.far;
		final point1 = farVerts[ 0 ];
		late Vector3 point2;
		if ( point1.distanceTo( farVerts[ 2 ] ) > point1.distanceTo( nearVerts[ 2 ] ) ) {
			point2 = farVerts[ 2 ];
		} else {
			point2 = nearVerts[ 2 ];
		}

		double squaredBBWidth = point1.distanceTo( point2 );
		if ( fade ) {
			// expand the shadow extents by the fade margin if fade is enabled.
			final camera = data.camera;
			final far = math.max( camera.far, data.maxFar );
			final linearDepth = frustum.vertices.far[ 0 ].z / ( far - camera.near );
			final margin = 0.25 * math.pow( linearDepth, 2.0 ) * ( far - camera.near );
			squaredBBWidth += margin;
		}

		shadowCam?.left = - squaredBBWidth / 2;
		shadowCam?.right = squaredBBWidth / 2;
		shadowCam?.top = squaredBBWidth / 2;
		shadowCam?.bottom = - squaredBBWidth / 2;
		shadowCam?.updateProjectionMatrix();
	}
}