Simplify patch rendering (#380)

* Make filter_intersections_outside_volume False by default

* Simplify patch rendering

Author: eigenvivek

diffdrr/drr.py

@@ -194,16 +194,12 @@ def render(
             **kwargs,
         )
     else:
-        n_points = target.shape[1] // self.n_patches
         partials = []
-        for idx in range(self.n_patches):
-            partial = self.renderer(
-                density,
-                source,
-                target[:, idx * n_points : (idx + 1) * n_points],
-                img[..., idx * n_points : (idx + 1) * n_points],
-                **kwargs,
-            )
+        for t, i in zip(
+            target.chunk(self.n_patches, dim=1),
+            img.chunk(self.n_patches, dim=-1),
+        ):
+            partial = self.renderer(density, source, t, i, **kwargs)
             partials.append(partial)
         img = torch.cat(partials, dim=-1)
 

diffdrr/renderers.py

@@ -15,7 +15,7 @@ def __init__(
         self,
         mode: str = "nearest",  # Interpolation mode for grid_sample
         stop_gradients_through_grid_sample: bool = False,  # Apply torch.no_grad when calling grid_sample
-        filter_intersections_outside_volume: bool = True,  # Use alphamin/max to filter the intersections
+        filter_intersections_outside_volume: bool = False,  # Use alphamin/max to filter the intersections
         reducefn: str = "sum",  # Function for combining samples along each ray
         eps: float = 1e-8,  # Small constant to avoid div by zero errors
     ):
@@ -51,7 +51,7 @@ def forward(
 
         # Calculate the midpoint of every pair of adjacent intersections
         # These midpoints lie exclusively in a single voxel
-        alphamid = (alphas[..., 0:-1] + alphas[..., 1:]) / 2
+        alphamid = (alphas[..., :-1] + alphas[..., 1:]) / 2
 
         # Get the XYZ coordinate of each midpoint (normalized to [-1, +1]^3)
         xyzs = _get_xyzs(alphamid, source, target, dims, self.eps)

notebooks/api/00_drr.ipynb

@@ -313,16 +313,12 @@
     "            **kwargs,\n",
     "        )\n",
     "    else:\n",
-    "        n_points = target.shape[1] // self.n_patches\n",
     "        partials = []\n",
-    "        for idx in range(self.n_patches):\n",
-    "            partial = self.renderer(\n",
-    "                density,\n",
-    "                source,\n",
-    "                target[:, idx * n_points : (idx + 1) * n_points],\n",
-    "                img[..., idx * n_points : (idx + 1) * n_points],\n",
-    "                **kwargs,\n",
-    "            )\n",
+    "        for t, i in zip(\n",
+    "            target.chunk(self.n_patches, dim=1),\n",
+    "            img.chunk(self.n_patches, dim=-1),\n",
+    "        ):\n",
+    "            partial = self.renderer(density, source, t, i, **kwargs)\n",
     "            partials.append(partial)\n",
     "        img = torch.cat(partials, dim=-1)\n",
     "\n",

notebooks/api/01_renderers.ipynb

@@ -117,7 +117,7 @@
     "        self,\n",
     "        mode: str = \"nearest\",  # Interpolation mode for grid_sample\n",
     "        stop_gradients_through_grid_sample: bool = False,  # Apply torch.no_grad when calling grid_sample\n",
-    "        filter_intersections_outside_volume: bool = True,  # Use alphamin/max to filter the intersections\n",
+    "        filter_intersections_outside_volume: bool = False,  # Use alphamin/max to filter the intersections\n",
     "        reducefn: str = \"sum\",  # Function for combining samples along each ray\n",
     "        eps: float = 1e-8,  # Small constant to avoid div by zero errors\n",
     "    ):\n",
@@ -153,7 +153,7 @@
     "\n",
     "        # Calculate the midpoint of every pair of adjacent intersections\n",
     "        # These midpoints lie exclusively in a single voxel\n",
-    "        alphamid = (alphas[..., 0:-1] + alphas[..., 1:]) / 2\n",
+    "        alphamid = (alphas[..., :-1] + alphas[..., 1:]) / 2\n",
     "\n",
     "        # Get the XYZ coordinate of each midpoint (normalized to [-1, +1]^3)\n",
     "        xyzs = _get_xyzs(alphamid, source, target, dims, self.eps)\n",