Ruilongli/docs (#6)

* build doc should wokr

* prettier doc

* Tensor

nerfacc/occupancy_field.py

@@ -33,22 +33,21 @@ def meshgrid3d(res: Tuple[int, int, int], device: torch.device = "cpu"):
 
 
 class OccupancyField(nn.Module):
-    """Occupancy Field that supports EMA updates.
+    """Occupancy Field that supports EMA updates. Both 2D and 3D are supported.
 
-    It supports both 2D and 3D cases, where in the 2D cases the occupancy field
-    is basically a segmentation mask.
+    Note:
+        Make sure the arguemnts match with the ``num_dim`` -- Either 2D or 3D.
 
     Args:
         occ_eval_fn: A Callable function that takes in the un-normalized points x,
-            with shape of (N, 2) or (N, 3) (depends on `num_dim`), and outputs
-            the occupancy of those points with shape of (N, 1).
-        aabb: Scene bounding box. {min_x, min_y, (min_z), max_x, max_y, (max_z)}.
-            It can be either a list or a torch.Tensor.
+            with shape of (N, 2) or (N, 3) (depends on ``num_dim``),
+            and outputs the occupancy of those points with shape of (N, 1).
+        aabb: Scene bounding box. If ``num_dim=2`` it should be {min_x, min_y,max_x, max_y}.
+            If ``num_dim=3`` it should be {min_x, min_y, min_z, max_x, max_y, max_z}.
         resolution: The field resolution. It can either be a int of a list of ints
-            to specify resolution on each dimention. {res_x, res_y, (res_z)}. Default
-            is 128.
-        num_dim: The space dimension. Either 2 or 3. Default is 3. Note other arguments
-            should match with the space dimension being set here.
+            to specify resolution on each dimention.  If ``num_dim=2`` it is for {res_x, res_y}.
+            If ``num_dim=3`` it is for {res_x, res_y, res_z}. Default is 128.
+        num_dim: The space dimension. Either 2 or 3. Default is 3.
     """
 
     def __init__(
@@ -114,23 +113,14 @@ class OccupancyField(nn.Module):
         return indices
 
     @torch.no_grad()
-    def update(
+    def _update(
         self,
         step: int,
-        occ_threshold: float = 0.01,
+        occ_thre: float = 0.01,
         ema_decay: float = 0.95,
         warmup_steps: int = 256,
     ) -> None:
-        """Update the occ field in the EMA way.
-
-        Args:
-            step: Current training step.
-            occ_threshold: Threshold to binarize the occupancy field.
-            ema_decay: The decay rate for EMA updates.
-            warmup_steps: Sample all cells during the warmup stage. After the warmup
-                stage we change the sampling strategy to 1/4 unifromly sampled cells
-                together with 1/4 occupied cells.
-        """
+        """Update the occ field in the EMA way."""
         # sample cells
         if step < warmup_steps:
             indices = self._get_all_cells()
@@ -157,7 +147,7 @@ class OccupancyField(nn.Module):
         )
         self.occ_grid_mean = self.occ_grid.mean()
         self.occ_grid_binary = self.occ_grid > torch.clamp(
-            self.occ_grid_mean, max=occ_threshold
+            self.occ_grid_mean, max=occ_thre
         )
 
     @torch.no_grad()
@@ -168,8 +158,7 @@ class OccupancyField(nn.Module):
             x: Samples with shape (..., 2) or (..., 3).
 
         Returns:
-            float occupancy values with shape (...),
-            binary occupancy values with shape (...)
+            float and binary occupancy values with shape (...) respectively.
         """
         assert (
             x.shape[-1] == self.num_dim
@@ -206,11 +195,27 @@ class OccupancyField(nn.Module):
         warmup_steps: int = 256,
         n: int = 16,
     ):
-        """Update the field every n steps during training."""
+        """Update the field every n steps during training.
+
+        This function is designed for training only. If for some reason you want to
+        manually update the field, please use the ``_update()`` function instead.
+
+        Args:
+            step: Current training step.
+            occ_thre: Threshold to binarize the occupancy field.
+            ema_decay: The decay rate for EMA updates.
+            warmup_steps: Sample all cells during the warmup stage. After the warmup
+                stage we change the sampling strategy to 1/4 unifromly sampled cells
+                together with 1/4 occupied cells.
+            n: Update the field every n steps.
+
+        Returns:
+            None
+        """
         if not self.training:
             raise RuntimeError(
                 "You should only call this function only during training. "
-                "Please call update() directly if you want to update the "
+                "Please call _update() directly if you want to update the "
                 "field during inference."
             )
         if step % n == 0 and self.training:

nerfacc/utils.py

 from typing import Tuple
 
 import torch
+from torch import Tensor
 
 import nerfacc.cuda as nerfacc_cuda
 
 
 @torch.no_grad()
 def ray_aabb_intersect(
-    rays_o: torch.Tensor, rays_d: torch.Tensor, aabb: torch.Tensor
-) -> Tuple[torch.Tensor, torch.Tensor]:
+    rays_o: Tensor, rays_d: Tensor, aabb: Tensor
+) -> Tuple[Tensor, Tensor]:
     """Ray AABB Test.
 
     Note: this function is not differentiable to inputs.
@@ -16,11 +17,11 @@ def ray_aabb_intersect(
     Args:
         rays_o: Ray origins. Tensor with shape (n_rays, 3).
         rays_d: Normalized ray directions. Tensor with shape (n_rays, 3).
-        aabb: Scene bounding box {xmin, ymin, zmin, xmax, ymax, zmax}.
+        aabb: Scene bounding box {xmin, ymin, zmin, xmax, ymax, zmax}. \
             Tensor with shape (6)
 
     Returns:
-        Ray AABB intersection {t_min, t_max} with shape (n_rays) respectively.
+        Ray AABB intersection {t_min, t_max} with shape (n_rays) respectively. \
         Note the t_min is clipped to minimum zero. 1e10 means no intersection.
 
     """
@@ -36,15 +37,15 @@ def ray_aabb_intersect(
 
 @torch.no_grad()
 def volumetric_marching(
-    rays_o: torch.Tensor,
-    rays_d: torch.Tensor,
-    aabb: torch.Tensor,
+    rays_o: Tensor,
+    rays_d: Tensor,
+    aabb: Tensor,
     scene_resolution: Tuple[int, int, int],
-    scene_occ_binary: torch.Tensor,
-    t_min: torch.Tensor = None,
-    t_max: torch.Tensor = None,
+    scene_occ_binary: Tensor,
+    t_min: Tensor = None,
+    t_max: Tensor = None,
     render_step_size: float = 1e-3,
-) -> Tuple[torch.Tensor, torch.Tensor, torch.Tensor, torch.Tensor, torch.Tensor]:
+) -> Tuple[Tensor, Tensor, Tensor, Tensor, Tensor]:
     """Volumetric marching with occupancy test.
 
     Note: this function is not differentiable to inputs.
@@ -52,26 +53,28 @@ def volumetric_marching(
     Args:
         rays_o: Ray origins. Tensor with shape (n_rays, 3).
         rays_d: Normalized ray directions. Tensor with shape (n_rays, 3).
-        aabb: Scene bounding box {xmin, ymin, zmin, xmax, ymax, zmax}.
+        aabb: Scene bounding box {xmin, ymin, zmin, xmax, ymax, zmax}. \
             Tensor with shape (6)
         scene_resolution: Shape of the `scene_occ_binary`. {resx, resy, resz}.
-        scene_occ_binary: Scene occupancy binary field. BoolTensor with shape
-        (resx * resy * resz)
-        t_min: Optional. Ray near planes. Tensor with shape (n_ray,).
+        scene_occ_binary: Scene occupancy binary field. BoolTensor with \
+            shape (resx * resy * resz)
+        t_min: Optional. Ray near planes. Tensor with shape (n_ray,). \
             If not given it will be calculated using aabb test. Default is None.
-        t_max: Optional. Ray far planes. Tensor with shape (n_ray,)
+        t_max: Optional. Ray far planes. Tensor with shape (n_ray,). \
             If not given it will be calculated using aabb test. Default is None.
         render_step_size: Marching step size. Default is 1e-3.
 
     Returns:
-        packed_info: Stores infomation on which samples belong to the same ray.
-        It is a tensor with shape (n_rays, 2). For each ray, the two values
-        indicate the start index and the number of samples for this ray,
+        A tuple of tensors containing
+
+            - **packed_info**: Stores infomation on which samples belong to the same ray. \
+                It is a tensor with shape (n_rays, 2). For each ray, the two values \
+                indicate the start index and the number of samples for this ray, \
                 respectively.
-        frustum_origins: Sampled frustum origins. Tensor with shape (n_samples, 3).
-        frustum_dirs: Sampled frustum directions. Tensor with shape (n_samples, 3).
-        frustum_starts: Sampled frustum starts. Tensor with shape (n_samples, 1).
-        frustum_ends: Sampled frustum ends. Tensor with shape (n_samples, 1).
+            - **frustum_origins**: Sampled frustum origins. Tensor with shape (n_samples, 3).
+            - **frustum_dirs**: Sampled frustum directions. Tensor with shape (n_samples, 3).
+            - **frustum_starts**: Sampled frustum directions. Tensor with shape (n_samples, 3).
+            - **frustum_ends**: Sampled frustum directions. Tensor with shape (n_samples, 3).
 
     """
     if not rays_o.is_cuda:
@@ -114,34 +117,36 @@ def volumetric_marching(
 
 @torch.no_grad()
 def volumetric_rendering_steps(
-    packed_info: torch.Tensor,
-    sigmas: torch.Tensor,
-    frustum_starts: torch.Tensor,
-    frustum_ends: torch.Tensor,
+    packed_info: Tensor,
+    sigmas: Tensor,
+    frustum_starts: Tensor,
+    frustum_ends: Tensor,
     *args,
-) -> Tuple[torch.Tensor, torch.Tensor, torch.Tensor]:
+) -> Tuple[Tensor, Tensor, Tensor]:
     """Compute rendering marching steps.
 
-    This function will compact the samples by terminate the marching once the
-    transmittance reaches to 0.9999. It is recommanded that before running your
-    network with gradients enabled, first run this function without gradients
+    This function will compact the samples by terminate the marching once the \
+    transmittance reaches to 0.9999. It is recommanded that before running your \
+    network with gradients enabled, first run this function without gradients \
     (torch.no_grad()) to quickly filter out some samples.
 
     Note: this function is not differentiable to inputs.
 
     Args:
-        packed_info: Stores infomation on which samples belong to the same ray.
-        See volumetric_marching for details. Tensor with shape (n_rays, 2).
+        packed_info: Stores infomation on which samples belong to the same ray. \
+            See volumetric_marching for details. Tensor with shape (n_rays, 2). \
             sigmas: Densities at those samples. Tensor with shape (n_samples, 1).
-        frustum_starts: Where the frustum-shape sample starts along a ray. Tensor with
+        frustum_starts: Where the frustum-shape sample starts along a ray. Tensor with \
             shape (n_samples, 1).
-        frustum_ends: Where the frustum-shape sample ends along a ray. Tensor with
+        frustum_ends: Where the frustum-shape sample ends along a ray. Tensor with \
             shape (n_samples, 1).
 
     Returns:
-        compact_packed_info: Compacted version of input packed_info.
-        compact_frustum_starts: Compacted version of input frustum_starts.
-        compact_frustum_ends: Compacted version of input frustum_ends.
+        A tuple of tensors containing
+
+            **compact_packed_info**: Compacted version of input packed_info.
+            **compact_frustum_starts**: Compacted version of input frustum_starts.
+            **compact_frustum_ends**: Compacted version of input frustum_ends.
 
     """
     if (
@@ -171,28 +176,29 @@ def volumetric_rendering_steps(
 
 
 def volumetric_rendering_weights(
-    packed_info: torch.Tensor,
-    sigmas: torch.Tensor,
-    frustum_starts: torch.Tensor,
-    frustum_ends: torch.Tensor,
-) -> Tuple[torch.Tensor, torch.Tensor, torch.Tensor]:
+    packed_info: Tensor,
+    sigmas: Tensor,
+    frustum_starts: Tensor,
+    frustum_ends: Tensor,
+) -> Tuple[Tensor, Tensor, Tensor]:
     """Compute weights for volumetric rendering.
 
     Note: this function is only differentiable to `sigmas`.
 
     Args:
-        packed_info: Stores infomation on which samples belong to the same ray.
-        See volumetric_marching for details. Tensor with shape (n_rays, 2).
+        packed_info: Stores infomation on which samples belong to the same ray. \
+            See ``volumetric_marching`` for details. Tensor with shape (n_rays, 2).
         sigmas: Densities at those samples. Tensor with shape (n_samples, 1).
-        frustum_starts: Where the frustum-shape sample starts along a ray. Tensor with
+        frustum_starts: Where the frustum-shape sample starts along a ray. Tensor with \
             shape (n_samples, 1).
-        frustum_ends: Where the frustum-shape sample ends along a ray. Tensor with
+        frustum_ends: Where the frustum-shape sample ends along a ray. Tensor with \
             shape (n_samples, 1).
 
     Returns:
-        weights: Volumetric rendering weights for those samples. Tensor with shape
-        (n_samples).
-        ray_indices: Ray index of each sample. IntTensor with shape (n_sample).
+        A tuple of tensors containing
+
+            - **weights**: Volumetric rendering weights for those samples. Tensor with shape (n_samples).
+            - **ray_indices**: Ray index of each sample. IntTensor with shape (n_sample).
 
     """
     if (
@@ -214,28 +220,28 @@ def volumetric_rendering_weights(
 
 
 def volumetric_rendering_accumulate(
-    weights: torch.Tensor,
-    ray_indices: torch.Tensor,
-    values: torch.Tensor = None,
+    weights: Tensor,
+    ray_indices: Tensor,
+    values: Tensor = None,
     n_rays: int = None,
-) -> torch.Tensor:
+) -> Tensor:
     """Accumulate volumetric values along the ray.
 
     Note: this function is only differentiable to weights and values.
 
     Args:
-        weights: Volumetric rendering weights for those samples. Tensor with shape
+        weights: Volumetric rendering weights for those samples. Tensor with shape \
             (n_samples).
         ray_indices: Ray index of each sample. IntTensor with shape (n_sample).
-        values: The values to be accmulated. Tensor with shape (n_samples, D). If
+        values: The values to be accmulated. Tensor with shape (n_samples, D). If \
             None, the accumulated values are just weights. Default is None.
-        n_rays: Total number of rays. This will decide the shape of the ouputs. If
-            None, it will be inferred from `ray_indices.max() + 1`.  If specified
+        n_rays: Total number of rays. This will decide the shape of the ouputs. If \
+            None, it will be inferred from `ray_indices.max() + 1`.  If specified \
             it should be at least larger than `ray_indices.max()`. Default is None.
 
     Returns:
-        Accumulated values with shape (n_rays, D). If `values` is not given then
-            we return the accumulated weights, in which case D == 1.
+        Accumulated values with shape (n_rays, D). If `values` is not given then we return \
+            the accumulated weights, in which case D == 1.
     """
     assert ray_indices.dim() == 1 and weights.dim() == 1
     if not weights.is_cuda: