'Computes the loss used for PTN paper (projection + volume loss).'

def get_loss(self, inputs, outputs):

    g_loss = tf.zeros(dtype=tf.float32, shape=[])
    if self._params.proj_weight:
        g_loss += losses.add_volume_proj_loss(inputs, outputs, self._params.step_size, self._params.proj_weight)
    if self._params.volume_weight:
        g_loss += losses.add_volume_loss(inputs, outputs, 1, self._params.volume_weight)
    slim.summaries.add_scalar_summary(g_loss, 'im2vox_loss', prefix='losses')
    return g_loss
