public boolean isIdentity() {
        return (m00 == 1 && m01 == 0 && m02 == 0)
                && (m10 == 0 && m11 == 1 && m12 == 0)
                && (m20 == 0 && m21 == 0 && m22 == 1);
    }
Tests for exact identity. The matrix is unaffected.

@return true if all diagonals = 1 and all other elements = 0 or -0,
otherwise false
jme3-core/src/main/java/com/jme3/math/Matrix3f.java