public Vector4f normalizeLocal() {
        // NOTE: this implementation is more optimized
        // than the old jme normalize as this method
        // is commonly used.
        float length = x * x + y * y + z * z + w * w;
        if (length != 1f && length != 0f) {
            length = 1.0f / FastMath.sqrt(length);
            x *= length;
            y *= length;
            z *= length;
            w *= length;
        }
        return this;
    }
<code>normalizeLocal</code> makes this vector into a unit vector of
itself.

@return this.
jme3-core/src/main/java/com/jme3/math/Vector4f.java