public static float calcScreenArea(BoundingVolume bound, float distance, float screenWidth) {
        if (bound.getType() == BoundingVolume.Type.Sphere) {
            return calcScreenArea((BoundingSphere) bound, distance, screenWidth);
        } else if (bound.getType() == BoundingVolume.Type.AABB) {
            return calcScreenArea((BoundingBox) bound, distance, screenWidth);
        }
        return 0.0f;
    }
Estimate the screen area of a bounding volume. If the volume isn't a
BoundingSphere, BoundingBox, or OrientedBoundingBox, 0 is returned.

@param bound The bounds to calculate the volume from.
@param distance The distance from camera to object.
@param screenWidth The width of the screen.
@return The area in pixels on the screen of the bounding volume.
jme3-core/src/main/java/com/jme3/util/AreaUtils.java