public void deleteInstance(Geometry geom) {
        int idx = InstancedNode.getGeometryStartIndex2(geom);
        InstancedNode.setGeometryStartIndex2(geom, -1);

        geometries[idx] = null;

        if (idx == firstUnusedIndex - 1) {
            // Deleting the last element.
            // Move index back.
            firstUnusedIndex--;
            while (geometries[firstUnusedIndex] == null) {
                firstUnusedIndex--;
                if (firstUnusedIndex < 0) {
                    break;
                }
            }
            firstUnusedIndex++;
        } else {
            // Deleting element in the middle
        }
        setBoundRefresh();
    }
@deprecated use {@link #updateInstances(com.jme3.renderer.Camera)}
jme3-core/src/main/java/com/jme3/scene/instancing/InstancedGeometry.java