private void inputMpo(MatParamOverride... overrides) {
        if (evaluated) {
            throw new IllegalStateException();
        }
        for (MatParamOverride override : overrides) {
            geometry.addMatParamOverride(override);
        }
        root.updateGeometricState();
    }
Validates {@link MatParam}s.

@author Kirill Vainer
jme3-core/src/test/java/com/jme3/material/MaterialMatParamTest.java