from typing import Callable, List, Dict, Tuple, Optional, Union import abc from mlagents.torch_utils import torch, nn from mlagents_envs.base_env import ActionSpec, SensorSpec from mlagents.trainers.torch.action_model import ActionModel from mlagents.trainers.torch.agent_action import AgentAction from mlagents.trainers.torch.action_log_probs import ActionLogProbs from mlagents.trainers.settings import NetworkSettings from mlagents.trainers.torch.utils import ModelUtils from mlagents.trainers.torch.decoders import ValueHeads from mlagents.trainers.torch.layers import LSTM, LinearEncoder from mlagents.trainers.torch.encoders import VectorInput from mlagents.trainers.buffer import AgentBuffer from mlagents.trainers.trajectory import ObsUtil from mlagents.trainers.torch.attention import SmallestAttention, EntityEmbeddings ActivationFunction = Callable[[torch.Tensor], torch.Tensor] EncoderFunction = Callable[ [torch.Tensor, int, ActivationFunction, int, str, bool], torch.Tensor ] EPSILON = 1e-7 class NetworkBody(nn.Module): def __init__( self, sensor_specs: List[SensorSpec], network_settings: NetworkSettings, encoded_act_size: int = 0, ): super().__init__() self.normalize = network_settings.normalize self.use_lstm = network_settings.memory is not None self.h_size = network_settings.hidden_units self.m_size = ( network_settings.memory.memory_size if network_settings.memory is not None else 0 ) self.processors, self.embedding_sizes = ModelUtils.create_input_processors( sensor_specs, self.h_size, network_settings.vis_encode_type, normalize=self.normalize, ) total_enc_size = sum(self.embedding_sizes) + encoded_act_size self.linear_encoder = LinearEncoder( total_enc_size, network_settings.num_layers, self.h_size ) if self.use_lstm: self.lstm = LSTM(self.h_size, self.m_size) else: self.lstm = None # type: ignore def update_normalization(self, buffer: AgentBuffer) -> None: obs = ObsUtil.from_buffer(buffer, len(self.processors)) for vec_input, enc in zip(obs, self.processors): if isinstance(enc, VectorInput): enc.update_normalization(torch.as_tensor(vec_input)) def copy_normalization(self, other_network: "NetworkBody") -> None: if self.normalize: for n1, n2 in zip(self.processors, other_network.processors): if isinstance(n1, VectorInput) and isinstance(n2, VectorInput): n1.copy_normalization(n2) @property def memory_size(self) -> int: return self.lstm.memory_size if self.use_lstm else 0 def forward( self, inputs: List[torch.Tensor], actions: Optional[torch.Tensor] = None, memories: Optional[torch.Tensor] = None, sequence_length: int = 1, ) -> Tuple[torch.Tensor, torch.Tensor]: encodes = [] for idx, processor in enumerate(self.processors): obs_input = inputs[idx] processed_obs = processor(obs_input) encodes.append(processed_obs) if len(encodes) == 0: raise Exception("No valid inputs to network.") # Constants don't work in Barracuda if actions is not None: inputs = torch.cat(encodes + [actions], dim=-1) else: inputs = torch.cat(encodes, dim=-1) encoding = self.linear_encoder(inputs) if self.use_lstm: # Resize to (batch, sequence length, encoding size) encoding = encoding.reshape([-1, sequence_length, self.h_size]) encoding, memories = self.lstm(encoding, memories) encoding = encoding.reshape([-1, self.m_size // 2]) return encoding, memories # NOTE: this class will be replaced with a multi-head attention when the time comes class MultiInputNetworkBody(nn.Module): def __init__( self, sensor_specs: List[SensorSpec], network_settings: NetworkSettings, encoded_act_size: int = 0, num_obs_heads: int = 1, ): super().__init__() self.normalize = network_settings.normalize self.use_lstm = network_settings.memory is not None # Scale network depending on num agents self.h_size = network_settings.hidden_units self.m_size = ( network_settings.memory.memory_size if network_settings.memory is not None else 0 ) self.processors, _input_size = ModelUtils.create_input_processors( sensor_specs, self.h_size, network_settings.vis_encode_type, normalize=self.normalize, ) self.transformer = SmallestAttention( sum(_input_size), [sum(_input_size)], self.h_size, self.h_size ) encoder_input_size = self.h_size + sum(_input_size) total_enc_size = encoder_input_size + encoded_act_size self.linear_encoder = LinearEncoder( total_enc_size, network_settings.num_layers, self.h_size ) if self.use_lstm: self.lstm = LSTM(self.h_size, self.m_size) else: self.lstm = None # type: ignore @property def memory_size(self) -> int: return self.lstm.memory_size if self.use_lstm else 0 def update_normalization(self, buffer: AgentBuffer) -> None: obs = ObsUtil.from_buffer(buffer, len(self.processors)) for vec_input, enc in zip(obs, self.processors): if isinstance(enc, VectorInput): enc.update_normalization(torch.as_tensor(vec_input)) def copy_normalization(self, other_network: "NetworkBody") -> None: if self.normalize: for n1, n2 in zip(self.processors, other_network.processors): if isinstance(n1, VectorInput) and isinstance(n2, VectorInput): n1.copy_normalization(n2) def forward( self, all_net_inputs: List[List[torch.Tensor]], actions: Optional[torch.Tensor] = None, memories: Optional[torch.Tensor] = None, sequence_length: int = 1, ) -> Tuple[torch.Tensor, torch.Tensor]: concat_encoded_obs = [] x_self = None self_encodes = [] inputs = all_net_inputs[0] for idx, processor in enumerate(self.processors): obs_input = inputs[idx] processed_obs = processor(obs_input) self_encodes.append(processed_obs) x_self = torch.cat(self_encodes, dim=-1) # Get the self encoding separately, but keep it in the entities concat_encoded_obs = [x_self] for inputs in all_net_inputs[1:]: encodes = [] for idx, processor in enumerate(self.processors): obs_input = inputs[idx] processed_obs = processor(obs_input) encodes.append(processed_obs) concat_encoded_obs.append(torch.cat(encodes, dim=-1)) concat_entites = torch.stack(concat_encoded_obs, dim=1) encoded_state = self.transformer( x_self, [concat_entites], EntityEmbeddings.get_masks([concat_entites]) ) if len(concat_encoded_obs) == 0: raise Exception("No valid inputs to network.") # Constants don't work in Barracuda if actions is not None: inputs = torch.cat([encoded_state, actions], dim=-1) else: inputs = encoded_state encoding = self.linear_encoder(inputs) if self.use_lstm: # Resize to (batch, sequence length, encoding size) encoding = encoding.reshape([-1, sequence_length, self.h_size]) encoding, memories = self.lstm(encoding, memories) encoding = encoding.reshape([-1, self.m_size // 2]) return encoding, memories class ValueNetwork(nn.Module): def __init__( self, stream_names: List[str], sensor_specs: List[SensorSpec], network_settings: NetworkSettings, encoded_act_size: int = 0, outputs_per_stream: int = 1, ): # This is not a typo, we want to call __init__ of nn.Module nn.Module.__init__(self) self.network_body = NetworkBody( sensor_specs, network_settings, encoded_act_size=encoded_act_size ) if network_settings.memory is not None: encoding_size = network_settings.memory.memory_size // 2 else: encoding_size = network_settings.hidden_units self.value_heads = ValueHeads(stream_names, encoding_size, outputs_per_stream) @property def memory_size(self) -> int: return self.network_body.memory_size def forward( self, inputs: List[torch.Tensor], actions: Optional[torch.Tensor] = None, memories: Optional[torch.Tensor] = None, sequence_length: int = 1, ) -> Tuple[Dict[str, torch.Tensor], torch.Tensor]: encoding, memories = self.network_body( inputs, actions, memories, sequence_length ) output = self.value_heads(encoding) return output, memories class CentralizedValueNetwork(ValueNetwork): def __init__( self, stream_names: List[str], observation_shapes: List[Tuple[int, ...]], network_settings: NetworkSettings, encoded_act_size: int = 0, outputs_per_stream: int = 1, ): # This is not a typo, we want to call __init__ of nn.Module nn.Module.__init__(self) self.network_body = MultiInputNetworkBody( observation_shapes, network_settings, encoded_act_size=encoded_act_size, ) if network_settings.memory is not None: encoding_size = network_settings.memory.memory_size // 2 else: encoding_size = network_settings.hidden_units self.value_heads = ValueHeads(stream_names, encoding_size, outputs_per_stream) def forward( self, inputs: List[List[torch.Tensor]], actions: Optional[torch.Tensor] = None, memories: Optional[torch.Tensor] = None, sequence_length: int = 1, ) -> Tuple[Dict[str, torch.Tensor], torch.Tensor]: encoding, memories = self.network_body( inputs, actions, memories, sequence_length ) output = self.value_heads(encoding) return output, memories class Actor(abc.ABC): @abc.abstractmethod def update_normalization(self, buffer: AgentBuffer) -> None: """ Updates normalization of Actor based on the provided List of vector obs. :param vector_obs: A List of vector obs as tensors. """ pass def get_action_stats( self, inputs: List[torch.Tensor], masks: Optional[torch.Tensor] = None, memories: Optional[torch.Tensor] = None, sequence_length: int = 1, ) -> Tuple[AgentAction, ActionLogProbs, torch.Tensor, torch.Tensor]: """ Returns sampled actions. If memory is enabled, return the memories as well. :param vec_inputs: A List of vector inputs as tensors. :param vis_inputs: A List of visual inputs as tensors. :param masks: If using discrete actions, a Tensor of action masks. :param memories: If using memory, a Tensor of initial memories. :param sequence_length: If using memory, the sequence length. :return: A Tuple of AgentAction, ActionLogProbs, entropies, and memories. Memories will be None if not using memory. """ pass @abc.abstractmethod def forward( self, vec_inputs: List[torch.Tensor], vis_inputs: List[torch.Tensor], masks: Optional[torch.Tensor] = None, memories: Optional[torch.Tensor] = None, ) -> Tuple[Union[int, torch.Tensor], ...]: """ Forward pass of the Actor for inference. This is required for export to ONNX, and the inputs and outputs of this method should not be changed without a respective change in the ONNX export code. """ pass class ActorCritic(Actor): @abc.abstractmethod def critic_pass( self, inputs: List[torch.Tensor], memories: Optional[torch.Tensor] = None, sequence_length: int = 1, ) -> Tuple[Dict[str, torch.Tensor], torch.Tensor]: """ Get value outputs for the given obs. :param inputs: List of inputs as tensors. :param memories: Tensor of memories, if using memory. Otherwise, None. :returns: Dict of reward stream to output tensor for values. """ pass @abc.abstractmethod def get_action_stats_and_value( self, inputs: List[torch.Tensor], masks: Optional[torch.Tensor] = None, memories: Optional[torch.Tensor] = None, sequence_length: int = 1, critic_obs: Optional[List[List[torch.Tensor]]] = None, ) -> Tuple[ AgentAction, ActionLogProbs, torch.Tensor, Dict[str, torch.Tensor], torch.Tensor ]: """ Returns sampled actions and value estimates. If memory is enabled, return the memories as well. :param inputs: A List of vector inputs as tensors. :param masks: If using discrete actions, a Tensor of action masks. :param memories: If using memory, a Tensor of initial memories. :param sequence_length: If using memory, the sequence length. :return: A Tuple of AgentAction, ActionLogProbs, entropies, Dict of reward signal name to value estimate, and memories. Memories will be None if not using memory. """ pass @abc.abstractproperty def memory_size(self): """ Returns the size of the memory (same size used as input and output in the other methods) used by this Actor. """ pass class SimpleActor(nn.Module, Actor): def __init__( self, sensor_specs: List[SensorSpec], network_settings: NetworkSettings, action_spec: ActionSpec, conditional_sigma: bool = False, tanh_squash: bool = False, ): super().__init__() self.action_spec = action_spec self.version_number = torch.nn.Parameter( torch.Tensor([2.0]), requires_grad=False ) self.is_continuous_int_deprecated = torch.nn.Parameter( torch.Tensor([int(self.action_spec.is_continuous())]), requires_grad=False ) self.continuous_act_size_vector = torch.nn.Parameter( torch.Tensor([int(self.action_spec.continuous_size)]), requires_grad=False ) # TODO: export list of branch sizes instead of sum self.discrete_act_size_vector = torch.nn.Parameter( torch.Tensor([sum(self.action_spec.discrete_branches)]), requires_grad=False ) self.act_size_vector_deprecated = torch.nn.Parameter( torch.Tensor( [ self.action_spec.continuous_size + sum(self.action_spec.discrete_branches) ] ), requires_grad=False, ) self.network_body = NetworkBody(sensor_specs, network_settings) if network_settings.memory is not None: self.encoding_size = network_settings.memory.memory_size // 2 else: self.encoding_size = network_settings.hidden_units self.memory_size_vector = torch.nn.Parameter( torch.Tensor([int(self.network_body.memory_size)]), requires_grad=False ) self.action_model = ActionModel( self.encoding_size, action_spec, conditional_sigma=conditional_sigma, tanh_squash=tanh_squash, ) @property def memory_size(self) -> int: return self.network_body.memory_size def update_normalization(self, buffer: AgentBuffer) -> None: self.network_body.update_normalization(buffer) def get_action_stats( self, inputs: List[torch.Tensor], masks: Optional[torch.Tensor] = None, memories: Optional[torch.Tensor] = None, sequence_length: int = 1, ) -> Tuple[AgentAction, ActionLogProbs, torch.Tensor, torch.Tensor]: encoding, memories = self.network_body( inputs, memories=memories, sequence_length=sequence_length ) action, log_probs, entropies = self.action_model(encoding, masks) return action, log_probs, entropies, memories def forward( self, vec_inputs: List[torch.Tensor], vis_inputs: List[torch.Tensor], masks: Optional[torch.Tensor] = None, memories: Optional[torch.Tensor] = None, ) -> Tuple[Union[int, torch.Tensor], ...]: """ Note: This forward() method is required for exporting to ONNX. Don't modify the inputs and outputs. At this moment, torch.onnx.export() doesn't accept None as tensor to be exported, so the size of return tuple varies with action spec. """ # This code will convert the vec and vis obs into a list of inputs for the network concatenated_vec_obs = vec_inputs[0] inputs = [] start = 0 end = 0 vis_index = 0 for i, enc in enumerate(self.network_body.processors): if isinstance(enc, VectorInput): # This is a vec_obs vec_size = self.network_body.embedding_sizes[i] end = start + vec_size inputs.append(concatenated_vec_obs[:, start:end]) start = end else: inputs.append(vis_inputs[vis_index]) vis_index += 1 # End of code to convert the vec and vis obs into a list of inputs for the network encoding, memories_out = self.network_body( inputs, memories=memories, sequence_length=1 ) ( cont_action_out, disc_action_out, action_out_deprecated, ) = self.action_model.get_action_out(encoding, masks) export_out = [self.version_number, self.memory_size_vector] if self.action_spec.continuous_size > 0: export_out += [cont_action_out, self.continuous_act_size_vector] if self.action_spec.discrete_size > 0: export_out += [disc_action_out, self.discrete_act_size_vector] # Only export deprecated nodes with non-hybrid action spec if self.action_spec.continuous_size == 0 or self.action_spec.discrete_size == 0: export_out += [ action_out_deprecated, self.is_continuous_int_deprecated, self.act_size_vector_deprecated, ] return tuple(export_out) class SharedActorCritic(SimpleActor, ActorCritic): def __init__( self, sensor_specs: List[SensorSpec], network_settings: NetworkSettings, action_spec: ActionSpec, stream_names: List[str], conditional_sigma: bool = False, tanh_squash: bool = False, ): self.use_lstm = network_settings.memory is not None super().__init__( sensor_specs, network_settings, action_spec, conditional_sigma, tanh_squash ) self.stream_names = stream_names self.value_heads = ValueHeads(stream_names, self.encoding_size) def critic_pass( self, inputs: List[torch.Tensor], memories: Optional[torch.Tensor] = None, sequence_length: int = 1, ) -> Tuple[Dict[str, torch.Tensor], torch.Tensor]: encoding, memories_out = self.network_body( inputs, memories=memories, sequence_length=sequence_length ) return self.value_heads(encoding), memories_out def get_stats_and_value( self, inputs: List[torch.Tensor], actions: AgentAction, masks: Optional[torch.Tensor] = None, memories: Optional[torch.Tensor] = None, sequence_length: int = 1, critic_obs: Optional[List[List[torch.Tensor]]] = None, ) -> Tuple[ActionLogProbs, torch.Tensor, Dict[str, torch.Tensor]]: encoding, memories = self.network_body( inputs, memories=memories, sequence_length=sequence_length, ) log_probs, entropies = self.action_model.evaluate(encoding, masks, actions) value_outputs = self.value_heads(encoding) return log_probs, entropies, value_outputs def get_action_stats_and_value( self, inputs: List[torch.Tensor], masks: Optional[torch.Tensor] = None, memories: Optional[torch.Tensor] = None, sequence_length: int = 1, ) -> Tuple[ AgentAction, ActionLogProbs, torch.Tensor, Dict[str, torch.Tensor], torch.Tensor ]: encoding, memories = self.network_body( inputs, memories=memories, sequence_length=sequence_length ) action, log_probs, entropies = self.action_model(encoding, masks) value_outputs = self.value_heads(encoding) return action, log_probs, entropies, value_outputs, memories class SeparateActorCritic(SimpleActor, ActorCritic): def __init__( self, sensor_specs: List[SensorSpec], network_settings: NetworkSettings, action_spec: ActionSpec, stream_names: List[str], conditional_sigma: bool = False, tanh_squash: bool = False, ): self.use_lstm = network_settings.memory is not None super().__init__( sensor_specs, network_settings, action_spec, conditional_sigma, tanh_squash ) self.stream_names = stream_names self.critic = CentralizedValueNetwork( stream_names, sensor_specs, network_settings ) @property def memory_size(self) -> int: return self.network_body.memory_size + self.critic.memory_size def _get_actor_critic_mem( self, memories: Optional[torch.Tensor] = None ) -> Tuple[Optional[torch.Tensor], Optional[torch.Tensor]]: if self.use_lstm and memories is not None: # Use only the back half of memories for critic and actor actor_mem, critic_mem = torch.split(memories, self.memory_size // 2, dim=-1) else: critic_mem = None actor_mem = None return actor_mem, critic_mem def critic_pass( self, inputs: List[torch.Tensor], memories: Optional[torch.Tensor] = None, sequence_length: int = 1, critic_obs: List[List[torch.Tensor]] = None, ) -> Tuple[Dict[str, torch.Tensor], torch.Tensor]: actor_mem, critic_mem = self._get_actor_critic_mem(memories) all_net_inputs = [inputs] if critic_obs is not None: all_net_inputs.extend(critic_obs) value_outputs, critic_mem_out = self.critic( all_net_inputs, memories=critic_mem, sequence_length=sequence_length ) if actor_mem is not None: # Make memories with the actor mem unchanged memories_out = torch.cat([actor_mem, critic_mem_out], dim=-1) else: memories_out = None return value_outputs, memories_out def get_stats_and_value( self, inputs: List[torch.Tensor], actions: AgentAction, masks: Optional[torch.Tensor] = None, memories: Optional[torch.Tensor] = None, sequence_length: int = 1, critic_obs: Optional[List[List[torch.Tensor]]] = None, ) -> Tuple[ActionLogProbs, torch.Tensor, Dict[str, torch.Tensor]]: actor_mem, critic_mem = self._get_actor_critic_mem(memories) encoding, actor_mem_outs = self.network_body( inputs, memories=actor_mem, sequence_length=sequence_length ) log_probs, entropies = self.action_model.evaluate(encoding, masks, actions) all_net_inputs = [inputs] if critic_obs is not None: all_net_inputs.extend(critic_obs) value_outputs, critic_mem_outs = self.critic( all_net_inputs, memories=critic_mem, sequence_length=sequence_length, ) return log_probs, entropies, value_outputs def get_action_stats( self, inputs: List[torch.Tensor], masks: Optional[torch.Tensor] = None, memories: Optional[torch.Tensor] = None, sequence_length: int = 1, ) -> Tuple[AgentAction, ActionLogProbs, torch.Tensor, torch.Tensor]: actor_mem, critic_mem = self._get_actor_critic_mem(memories) action, log_probs, entropies, actor_mem_out = super().get_action_stats( inputs, masks=masks, memories=actor_mem, sequence_length=sequence_length ) if critic_mem is not None: # Make memories with the actor mem unchanged memories_out = torch.cat([actor_mem_out, critic_mem], dim=-1) else: memories_out = None return action, log_probs, entropies, memories_out def get_action_stats_and_value( self, inputs: List[torch.Tensor], masks: Optional[torch.Tensor] = None, memories: Optional[torch.Tensor] = None, sequence_length: int = 1, critic_obs: Optional[List[List[torch.Tensor]]] = None, ) -> Tuple[ AgentAction, ActionLogProbs, torch.Tensor, Dict[str, torch.Tensor], torch.Tensor ]: actor_mem, critic_mem = self._get_actor_critic_mem(memories) encoding, actor_mem_outs = self.network_body( inputs, memories=actor_mem, sequence_length=sequence_length ) action, log_probs, entropies = self.action_model(encoding, masks) all_net_inputs = [inputs] if critic_obs is not None: all_net_inputs.extend(critic_obs) value_outputs, critic_mem_outs = self.critic( all_net_inputs, memories=critic_mem, sequence_length=sequence_length ) if self.use_lstm: mem_out = torch.cat([actor_mem_outs, critic_mem_outs], dim=-1) else: mem_out = None return action, log_probs, entropies, value_outputs, mem_out def update_normalization(self, buffer: AgentBuffer) -> None: super().update_normalization(buffer) self.critic.network_body.update_normalization(buffer) class GlobalSteps(nn.Module): def __init__(self): super().__init__() self.__global_step = nn.Parameter( torch.Tensor([0]).to(torch.int64), requires_grad=False ) @property def current_step(self): return int(self.__global_step.item()) @current_step.setter def current_step(self, value): self.__global_step[:] = value def increment(self, value): self.__global_step += value class LearningRate(nn.Module): def __init__(self, lr): # Todo: add learning rate decay super().__init__() self.learning_rate = torch.Tensor([lr])