public void setGlobalUserInstanceData(VertexBuffer[] globalInstanceData) {
        this.globalInstanceData = globalInstanceData;
        updateAllInstanceData();
    }
Specify global user per-instance data.

By default set to <code>null</code>, specify an array of VertexBuffers
that contain per-instance vertex attributes.

@param globalInstanceData global user per-instance data.

@throws IllegalArgumentException If one of the VertexBuffers is not
{@link VertexBuffer#setInstanced(boolean) instanced}.
jme3-core/src/main/java/com/jme3/scene/instancing/InstancedGeometry.java