Converts this vector3 into a vector4 instance.

def to_vec4(self, isPoint):
        """Converts this vector3 into a vector4 instance."""
        vec4 = Vector4()
        vec4.x = self.x
        vec4.y = self.y
        vec4.z = self.z
        if isPoint:
            vec4.w = 1
        else:
            vec4.w = 0

        return vec4