public int getNumElements() {
        if (data == null) {
            return 0;
        }
        int elements = data.limit() / components;
        if (format == Format.Half) {
            elements /= 2;
        }
        return elements;
    }
@return The total number of data elements in the data buffer.
jme3-core/src/main/java/com/jme3/scene/VertexBuffer.java