ray/rllib/models/torch/visionnet.py
Balaji Veeramani 7f1bacc7dc
[CI] Format Python code with Black (#21975)
See #21316 and #21311 for the motivation behind these changes.
2022-01-29 18:41:57 -08:00

293 lines
10 KiB
Python

import numpy as np
from typing import Dict, List
import gym
from ray.rllib.models.torch.torch_modelv2 import TorchModelV2
from ray.rllib.models.torch.misc import (
normc_initializer,
same_padding,
SlimConv2d,
SlimFC,
)
from ray.rllib.models.utils import get_activation_fn, get_filter_config
from ray.rllib.utils.annotations import override
from ray.rllib.utils.framework import try_import_torch
from ray.rllib.utils.typing import ModelConfigDict, TensorType
torch, nn = try_import_torch()
class VisionNetwork(TorchModelV2, nn.Module):
"""Generic vision network."""
def __init__(
self,
obs_space: gym.spaces.Space,
action_space: gym.spaces.Space,
num_outputs: int,
model_config: ModelConfigDict,
name: str,
):
if not model_config.get("conv_filters"):
model_config["conv_filters"] = get_filter_config(obs_space.shape)
TorchModelV2.__init__(
self, obs_space, action_space, num_outputs, model_config, name
)
nn.Module.__init__(self)
activation = self.model_config.get("conv_activation")
filters = self.model_config["conv_filters"]
assert len(filters) > 0, "Must provide at least 1 entry in `conv_filters`!"
# Post FC net config.
post_fcnet_hiddens = model_config.get("post_fcnet_hiddens", [])
post_fcnet_activation = get_activation_fn(
model_config.get("post_fcnet_activation"), framework="torch"
)
no_final_linear = self.model_config.get("no_final_linear")
vf_share_layers = self.model_config.get("vf_share_layers")
# Whether the last layer is the output of a Flattened (rather than
# a n x (1,1) Conv2D).
self.last_layer_is_flattened = False
self._logits = None
layers = []
(w, h, in_channels) = obs_space.shape
in_size = [w, h]
for out_channels, kernel, stride in filters[:-1]:
padding, out_size = same_padding(in_size, kernel, stride)
layers.append(
SlimConv2d(
in_channels,
out_channels,
kernel,
stride,
padding,
activation_fn=activation,
)
)
in_channels = out_channels
in_size = out_size
out_channels, kernel, stride = filters[-1]
# No final linear: Last layer has activation function and exits with
# num_outputs nodes (this could be a 1x1 conv or a FC layer, depending
# on `post_fcnet_...` settings).
if no_final_linear and num_outputs:
out_channels = out_channels if post_fcnet_hiddens else num_outputs
layers.append(
SlimConv2d(
in_channels,
out_channels,
kernel,
stride,
None, # padding=valid
activation_fn=activation,
)
)
# Add (optional) post-fc-stack after last Conv2D layer.
layer_sizes = post_fcnet_hiddens[:-1] + (
[num_outputs] if post_fcnet_hiddens else []
)
for i, out_size in enumerate(layer_sizes):
layers.append(
SlimFC(
in_size=out_channels,
out_size=out_size,
activation_fn=post_fcnet_activation,
initializer=normc_initializer(1.0),
)
)
out_channels = out_size
# Finish network normally (w/o overriding last layer size with
# `num_outputs`), then add another linear one of size `num_outputs`.
else:
layers.append(
SlimConv2d(
in_channels,
out_channels,
kernel,
stride,
None, # padding=valid
activation_fn=activation,
)
)
# num_outputs defined. Use that to create an exact
# `num_output`-sized (1,1)-Conv2D.
if num_outputs:
in_size = [
np.ceil((in_size[0] - kernel[0]) / stride),
np.ceil((in_size[1] - kernel[1]) / stride),
]
padding, _ = same_padding(in_size, [1, 1], [1, 1])
if post_fcnet_hiddens:
layers.append(nn.Flatten())
in_size = out_channels
# Add (optional) post-fc-stack after last Conv2D layer.
for i, out_size in enumerate(post_fcnet_hiddens + [num_outputs]):
layers.append(
SlimFC(
in_size=in_size,
out_size=out_size,
activation_fn=post_fcnet_activation
if i < len(post_fcnet_hiddens) - 1
else None,
initializer=normc_initializer(1.0),
)
)
in_size = out_size
# Last layer is logits layer.
self._logits = layers.pop()
else:
self._logits = SlimConv2d(
out_channels,
num_outputs,
[1, 1],
1,
padding,
activation_fn=None,
)
# num_outputs not known -> Flatten, then set self.num_outputs
# to the resulting number of nodes.
else:
self.last_layer_is_flattened = True
layers.append(nn.Flatten())
self._convs = nn.Sequential(*layers)
# If our num_outputs still unknown, we need to do a test pass to
# figure out the output dimensions. This could be the case, if we have
# the Flatten layer at the end.
if self.num_outputs is None:
# Create a B=1 dummy sample and push it through out conv-net.
dummy_in = (
torch.from_numpy(self.obs_space.sample())
.permute(2, 0, 1)
.unsqueeze(0)
.float()
)
dummy_out = self._convs(dummy_in)
self.num_outputs = dummy_out.shape[1]
# Build the value layers
self._value_branch_separate = self._value_branch = None
if vf_share_layers:
self._value_branch = SlimFC(
out_channels, 1, initializer=normc_initializer(0.01), activation_fn=None
)
else:
vf_layers = []
(w, h, in_channels) = obs_space.shape
in_size = [w, h]
for out_channels, kernel, stride in filters[:-1]:
padding, out_size = same_padding(in_size, kernel, stride)
vf_layers.append(
SlimConv2d(
in_channels,
out_channels,
kernel,
stride,
padding,
activation_fn=activation,
)
)
in_channels = out_channels
in_size = out_size
out_channels, kernel, stride = filters[-1]
vf_layers.append(
SlimConv2d(
in_channels,
out_channels,
kernel,
stride,
None,
activation_fn=activation,
)
)
vf_layers.append(
SlimConv2d(
in_channels=out_channels,
out_channels=1,
kernel=1,
stride=1,
padding=None,
activation_fn=None,
)
)
self._value_branch_separate = nn.Sequential(*vf_layers)
# Holds the current "base" output (before logits layer).
self._features = None
@override(TorchModelV2)
def forward(
self,
input_dict: Dict[str, TensorType],
state: List[TensorType],
seq_lens: TensorType,
) -> (TensorType, List[TensorType]):
self._features = input_dict["obs"].float()
# Permuate b/c data comes in as [B, dim, dim, channels]:
self._features = self._features.permute(0, 3, 1, 2)
conv_out = self._convs(self._features)
# Store features to save forward pass when getting value_function out.
if not self._value_branch_separate:
self._features = conv_out
if not self.last_layer_is_flattened:
if self._logits:
conv_out = self._logits(conv_out)
if len(conv_out.shape) == 4:
if conv_out.shape[2] != 1 or conv_out.shape[3] != 1:
raise ValueError(
"Given `conv_filters` ({}) do not result in a [B, {} "
"(`num_outputs`), 1, 1] shape (but in {})! Please "
"adjust your Conv2D stack such that the last 2 dims "
"are both 1.".format(
self.model_config["conv_filters"],
self.num_outputs,
list(conv_out.shape),
)
)
logits = conv_out.squeeze(3)
logits = logits.squeeze(2)
else:
logits = conv_out
return logits, state
else:
return conv_out, state
@override(TorchModelV2)
def value_function(self) -> TensorType:
assert self._features is not None, "must call forward() first"
if self._value_branch_separate:
value = self._value_branch_separate(self._features)
value = value.squeeze(3)
value = value.squeeze(2)
return value.squeeze(1)
else:
if not self.last_layer_is_flattened:
features = self._features.squeeze(3)
features = features.squeeze(2)
else:
features = self._features
return self._value_branch(features).squeeze(1)
def _hidden_layers(self, obs: TensorType) -> TensorType:
res = self._convs(obs.permute(0, 3, 1, 2)) # switch to channel-major
res = res.squeeze(3)
res = res.squeeze(2)
return res