skeleton of pluggable IO

Summary: Unified interface for loading and saving meshes and pointclouds.

Reviewed By: nikhilaravi

Differential Revision: D25372968

fbshipit-source-id: 6fe57cc3704a89d81d13e959bee707b0c7b57d3b

docs/notes/io.md

@@ -0,0 +1,24 @@
+---
+hide_title: true
+sidebar_label: File IO
+---
+
+# File IO
+There is a flexible interface for loading and saving point clouds and meshes from different formats.
+
+The main usage is via the `pytorch3d.io.IO` object, and its methods
+`load_mesh`, `save_mesh`, `load_point_cloud` and `save_point_cloud`.
+
+For example, to load a mesh you might do
+```
+from pytorch3d.io import IO
+
+device=torch.device("cuda:0")
+mesh = IO().load_mesh("mymesh.ply", device=device)
+```
+
+and to save a pointcloud you might do
+```
+pcl = Pointclouds(...)
+IO().save_point_cloud(pcl, "output_poincloud.obj")
+```

pytorch3d/io/__init__.py

@@ -2,6 +2,7 @@
 
 
 from .obj_io import load_obj, load_objs_as_meshes, save_obj
+from .pluggable import IO
 from .ply_io import load_ply, save_ply
 
 

pytorch3d/io/pluggable.py

@@ -0,0 +1,208 @@
+# Copyright (c) Facebook, Inc. and its affiliates. All rights reserved.
+# This source code is licensed under the license found in the
+# LICENSE file in the root directory of this source tree.
+
+
+from collections import deque
+from pathlib import Path
+from typing import Deque, Optional, Union
+
+from iopath.common.file_io import PathManager
+from pytorch3d.structures import Meshes, Pointclouds
+
+from .pluggable_formats import MeshFormatInterpreter, PointcloudFormatInterpreter
+
+
+"""
+This module has the master functions for loading and saving data.
+
+The main usage is via the IO object, and its methods
+`load_mesh`, `save_mesh`, `load_pointcloud` and `save_pointcloud`.
+
+For example, to load a mesh you might do
+```
+from pytorch3d.io import IO
+
+mesh = IO().load_mesh("mymesh.obj")
+```
+
+and to save a point cloud you might do
+
+```
+pcl = Pointclouds(...)
+IO().save_pointcloud(pcl, "output_poincloud.obj")
+```
+
+"""
+
+
+class IO:
+    """
+    This class is the interface to flexible loading and saving of meshes and point clouds.
+
+    In simple cases the user will just initialise an instance of this class as `IO()`
+    and then use its load and save functions. The arguments of the initializer are not
+    usually needed.
+
+    The user can add their own formats for saving and loading by passing their own objects
+    to the register_* functions.
+
+    Args:
+        include_default_formats: If False, the built-in file formats will not be available.
+            Then only user-registered formats can be used.
+        path_manager: Used to customise how paths given as strings are interpreted.
+    """
+
+    def __init__(
+        self,
+        include_default_formats: bool = True,
+        path_manager: Optional[PathManager] = None,
+    ):
+        if path_manager is None:
+            self.path_manager = PathManager()
+        else:
+            self.path_manager = path_manager
+
+        self.mesh_interpreters: Deque[MeshFormatInterpreter] = deque()
+        self.pointcloud_interpreters: Deque[PointcloudFormatInterpreter] = deque()
+
+        if include_default_formats:
+            self.register_default_formats()
+
+    def register_default_formats(self) -> None:
+        # This will be populated in later diffs
+        pass
+
+    def register_meshes_format(self, interpreter: MeshFormatInterpreter) -> None:
+        """
+        Register a new interpreter for a new mesh file format.
+
+        Args:
+            interpreter: the new interpreter to use, which must be an instance
+                of a class which inherits MeshFormatInterpreter.
+        """
+        self.mesh_interpreters.appendleft(interpreter)
+
+    def register_pointcloud_format(
+        self, interpreter: PointcloudFormatInterpreter
+    ) -> None:
+        """
+        Register a new interpreter for a new point cloud file format.
+
+        Args:
+            interpreter: the new interpreter to use, which must be an instance
+                of a class which inherits PointcloudFormatInterpreter.
+        """
+        self.pointcloud_interpreters.appendleft(interpreter)
+
+    def load_mesh(
+        self,
+        path: Union[str, Path],
+        include_textures: bool = True,
+        device="cpu",
+        **kwargs,
+    ) -> Meshes:
+        """
+        Attempt to load a mesh from the given file, using a registered format.
+        Materials are not returned. If you have a .obj file with materials
+        you might want to load them with the load_obj function instead.
+
+        Args:
+            path: file to read
+            include_textures: whether to try to load texture information
+            device: device on which to leave the data.
+
+        Returns:
+            new Meshes object containing one mesh.
+        """
+        for mesh_interpreter in self.mesh_interpreters:
+            mesh = mesh_interpreter.read(
+                path,
+                include_textures=include_textures,
+                path_manager=self.path_manager,
+                device=device,
+                **kwargs,
+            )
+            if mesh is not None:
+                return mesh
+
+        raise ValueError(f"No mesh interpreter found to read {path}.")
+
+    def save_mesh(
+        self,
+        data: Meshes,
+        path: Union[str, Path],
+        binary: Optional[bool] = None,
+        include_textures: bool = True,
+        **kwargs,
+    ) -> None:
+        """
+        Attempt to save a mesh to the given file, using a registered format.
+
+        Args:
+            data: a 1-element Meshes
+            path: file to write
+            binary: If there is a choice, whether to save in a binary format.
+            include_textures: If textures are present, whether to try to save
+                                them.
+        """
+        if len(data) != 1:
+            raise ValueError("Can only save a single mesh.")
+
+        for mesh_interpreter in self.mesh_interpreters:
+            success = mesh_interpreter.save(
+                data, path, path_manager=self.path_manager, binary=binary, **kwargs
+            )
+            if success:
+                return
+
+        raise ValueError(f"No mesh interpreter found to write to {path}.")
+
+    def load_pointcloud(
+        self, path: Union[str, Path], device="cpu", **kwargs
+    ) -> Pointclouds:
+        """
+        Attempt to load a point cloud from the given file, using a registered format.
+
+        Args:
+            path: file to read
+            device: torch.device on which to load the data.
+
+        Returns:
+            new Pointclouds object containing one mesh.
+        """
+        for pointcloud_interpreter in self.pointcloud_interpreters:
+            pointcloud = pointcloud_interpreter.read(
+                path, path_manager=self.path_manager, device=device, **kwargs
+            )
+            if pointcloud is not None:
+                return pointcloud
+
+        raise ValueError(f"No point cloud interpreter found to read {path}.")
+
+    def save_pointcloud(
+        self,
+        data: Pointclouds,
+        path: Union[str, Path],
+        binary: Optional[bool] = None,
+        **kwargs,
+    ) -> None:
+        """
+        Attempt to save a point cloud to the given file, using a registered format.
+
+        Args:
+            data: a 1-element Pointclouds
+            path: file to write
+            binary: If there is a choice, whether to save in a binary format.
+        """
+        if len(data) != 1:
+            raise ValueError("Can only save a single point cloud.")
+
+        for pointcloud_interpreter in self.pointcloud_interpreters:
+            success = pointcloud_interpreter.save(
+                data, path, path_manager=self.path_manager, binary=binary, **kwargs
+            )
+            if success:
+                return
+
+        raise ValueError(f"No point cloud interpreter found to write to {path}.")

pytorch3d/io/pluggable_formats.py

@@ -0,0 +1,136 @@
+# Copyright (c) Facebook, Inc. and its affiliates. All rights reserved.
+# This source code is licensed under the license found in the
+# LICENSE file in the root directory of this source tree.
+
+
+from pathlib import Path
+from typing import Optional, Tuple, Union
+
+from iopath.common.file_io import PathManager
+from pytorch3d.structures import Meshes, Pointclouds
+
+
+"""
+This module has the base classes which must be extended to define
+an interpreter for loading and saving data in a particular format.
+These can be registered on an IO object so that they can be used in
+its load_* and save_* functions.
+"""
+
+
+def endswith(path, suffixes: Tuple[str, ...]) -> bool:
+    """
+    Returns whether the path ends with one of the given suffixes.
+    If `path` is not actually a path, returns True. This is useful
+    for allowing interpreters to bypass inappropriate paths, but
+    always accepting streams.
+    """
+    if isinstance(path, Path):
+        return path.suffix.lower() in suffixes
+    if isinstance(path, str):
+        return path.lower().endswith(suffixes)
+    return True
+
+
+class MeshFormatInterpreter:
+    """
+    This is a base class for an interpreter which can read or write
+    a mesh in a particular format.
+    """
+
+    def read(
+        self,
+        path: Union[str, Path],
+        include_textures: bool,
+        device,
+        path_manager: PathManager,
+        **kwargs,
+    ) -> Optional[Meshes]:
+        """
+        Read the data from the specified file and return it as
+        a Meshes object.
+
+        Args:
+            path: path to load.
+            include_textures: whether to try to load texture information.
+            device: torch.device to load data on to.
+            path_manager: PathManager to interpret the path.
+
+        Returns:
+            None if self is not the appropriate object to interpret the given
+                path.
+            Otherwise, the read Meshes object.
+        """
+        raise NotImplementedError()
+
+    def save(
+        self,
+        data: Meshes,
+        path: Union[str, Path],
+        path_manager: PathManager,
+        binary: Optional[bool],
+        **kwargs,
+    ) -> bool:
+        """
+        Save the given Meshes object to the given path.
+
+        Args:
+            data: mesh to save
+            path: path to save to, which may be overwritten.
+            path_manager: PathManager to interpret the path.
+            binary: If there is a choice, whether to save in a binary format.
+
+        Returns:
+            False: if self is not the appropriate object to write to the given path.
+            True: on success.
+        """
+        raise NotImplementedError()
+
+
+class PointcloudFormatInterpreter:
+    """
+    This is a base class for an interpreter which can read or write
+    a point cloud in a particular format.
+    """
+
+    def read(
+        self, path: Union[str, Path], device, path_manager: PathManager, **kwargs
+    ) -> Optional[Pointclouds]:
+        """
+        Read the data from the specified file and return it as
+        a Pointclouds object.
+
+        Args:
+            path: path to load.
+            device: torch.device to load data on to.
+            path_manager: PathManager to interpret the path.
+
+        Returns:
+            None if self is not the appropriate object to interpret the given
+                path.
+            Otherwise, the read Pointclouds object.
+        """
+        raise NotImplementedError()
+
+    def save(
+        self,
+        data: Pointclouds,
+        path: Union[str, Path],
+        path_manager: PathManager,
+        binary: Optional[bool],
+        **kwargs,
+    ) -> bool:
+        """
+        Save the given Pointclouds object to the given path.
+
+        Args:
+            data: point cloud object to save
+            path: path to save to, which may be overwritten.
+            path_manager: PathManager to interpret the path.
+            binary: If there is a choice, whether to save in a binary format.
+
+        Returns:
+            False: if self is not the appropriate object to write to the given path.
+            True: on success.
+        """
+        raise NotImplementedError()

pytorch3d/structures/pointclouds.py

@@ -777,7 +777,7 @@ class Pointclouds(object):
             returned.
 
         Returns:
-            list[PointClouds].
+            list[Pointclouds].
         """
         if not all(isinstance(x, int) for x in split_sizes):
             raise ValueError("Value of split_sizes must be a list of integers.")