@Override
    public void write(JmeExporter ex) throws IOException {
        OutputCapsule oc = ex.getCapsule(this);
        oc.write(type, "varType", null);
        oc.write(name, "name", null);

        if (value == null) {
            return;
        }

        if (value instanceof Savable) {
            oc.write((Savable) value, "value_savable", null);
        } else if (value instanceof Float) {
            oc.write((Float) value, "value_float", 0f);
        } else if (value instanceof Integer) {
            oc.write((Integer) value, "value_int", 0);
        } else if (value instanceof Boolean) {
            oc.write((Boolean) value, "value_bool", false);
        } else if (value.getClass().isArray() && value instanceof Savable[]) {
            oc.write((Savable[]) value, "value_savable_array", null);
        }

        oc.write(typeCheck, "typeCheck", true);
    }
Returns the material parameter value as it would appear in a J3M
file. E.g.
<pre>
MaterialParameters {
    ABC : 1 2 3 4
}
</pre>
Assuming "ABC" is a Vector4 parameter, then the value
"1 2 3 4" would be returned by this method.

@return material parameter value as it would appear in a J3M file.
jme3-core/src/main/java/com/jme3/material/MatParam.java