public boolean isSimilar(Vector4f other, float epsilon) {
        if (other == null) {
            return false;
        }
        if (Float.compare(Math.abs(other.x - x), epsilon) > 0) {
            return false;
        }
        if (Float.compare(Math.abs(other.y - y), epsilon) > 0) {
            return false;
        }
        if (Float.compare(Math.abs(other.z - z), epsilon) > 0) {
            return false;
        }
        if (Float.compare(Math.abs(other.w - w), epsilon) > 0) {
            return false;
        }
        return true;
    }
Returns true if this vector is similar to the specified vector within
some value of epsilon.

@param other the vector to compare with (not null, unaffected)
@param epsilon the desired error tolerance for each component
@return true if all 4 components are within tolerance, otherwise false
jme3-core/src/main/java/com/jme3/math/Vector4f.java