import tensorflow as tf

        self.ri = tf.placeholder(tf.float32, (None,))
        self.s_diff = tf.placeholder(tf.float32, (None, self.g_dim))

    def build_perception(self):
        self._obs = tf.expand_dims(self.obs, -1)  # !
        self._obs = tf.expand_dims(self._obs, -1)  # !
        conv1 = tf.layers.conv2d(inputs=self._obs,
                                 filters=16,
