public boolean isIdentity() {
        return (m00 == 1 && m01 == 0 && m02 == 0 && m03 == 0)
                && (m10 == 0 && m11 == 1 && m12 == 0 && m13 == 0)
                && (m20 == 0 && m21 == 0 && m22 == 1 && m23 == 0)
                && (m30 == 0 && m31 == 0 && m32 == 0 && m33 == 1);
    }
Test for exact identity.

@return true if this is an exact identity, otherwise false
jme3-core/src/main/java/com/jme3/math/Matrix4f.java