Update Rasterizer and add end2end fisheye integration test

Summary:
1) Update rasterizer/point rasterizer to accommodate fisheyecamera. Specifically, transform_points is in placement of explicit transform compositions.

2) In rasterizer unittests, update corresponding tests for rasterizer and point_rasterizer. Address comments to test fisheye against perspective camera when distortions are turned off.

3) Address comments to add end2end test for fisheyecameras. In test_render_meshes, fisheyecameras are added to camera enuerations whenever possible.

4) Test renderings with fisheyecameras of different params on cow mesh.

5) Use compositions for linear cameras whenever possible.

Reviewed By: kjchalup

Differential Revision: D38932736

fbshipit-source-id: 5b7074fc001f2390f4cf43c7267a8b37fd987547

pytorch3d/renderer/cameras.py

@@ -6,7 +6,7 @@
 
 import math
 import warnings
-from typing import List, Optional, Sequence, Tuple, Union
+from typing import Callable, List, Optional, Sequence, Tuple, Union
 
 import numpy as np
 import torch
@@ -91,7 +91,7 @@ class CamerasBase(TensorProperties):
     # When joining objects into a batch, they will have to agree.
     _SHARED_FIELDS: Tuple[str, ...] = ()
 
-    def get_projection_transform(self):
+    def get_projection_transform(self, **kwargs):
         """
         Calculate the projective transformation matrix.
 
@@ -1841,3 +1841,23 @@ def get_screen_to_ndc_transform(
         image_size=image_size,
     ).inverse()
     return transform
+
+
+def try_get_projection_transform(cameras, kwargs) -> Optional[Callable]:
+    """
+    Try block to get projection transform.
+
+    Args:
+        cameras instance, can be linear cameras or nonliear cameras
+
+    Returns:
+        If the camera implemented projection_transform, return the
+        projection transform; Otherwise, return None
+    """
+
+    transform = None
+    try:
+        transform = cameras.get_projection_transform(**kwargs)
+    except NotImplementedError:
+        pass
+    return transform

pytorch3d/renderer/mesh/rasterizer.py

@@ -9,6 +9,7 @@ from typing import Optional, Tuple, Union
 
 import torch
 import torch.nn as nn
+from pytorch3d.renderer.cameras import try_get_projection_transform
 
 from .rasterize_meshes import rasterize_meshes
 
@@ -197,12 +198,19 @@ class MeshRasterizer(nn.Module):
         verts_view = cameras.get_world_to_view_transform(**kwargs).transform_points(
             verts_world, eps=eps
         )
-        # view to NDC transform
+        # Call transform_points instead of explicitly composing transforms to handle
+        # the case, where camera class does not have a projection matrix form.
+        verts_proj = cameras.transform_points(verts_world, eps=eps)
         to_ndc_transform = cameras.get_ndc_camera_transform(**kwargs)
-        projection_transform = cameras.get_projection_transform(**kwargs).compose(
-            to_ndc_transform
-        )
-        verts_ndc = projection_transform.transform_points(verts_view, eps=eps)
+        projection_transform = try_get_projection_transform(cameras, kwargs)
+        if projection_transform is not None:
+            projection_transform = projection_transform.compose(to_ndc_transform)
+            verts_ndc = projection_transform.transform_points(verts_view, eps=eps)
+        else:
+            # Call transform_points instead of explicitly composing transforms to handle
+            # the case, where camera class does not have a projection matrix form.
+            verts_proj = cameras.transform_points(verts_world, eps=eps)
+            verts_ndc = to_ndc_transform.transform_points(verts_proj, eps=eps)
 
         verts_ndc[..., 2] = verts_view[..., 2]
         meshes_ndc = meshes_world.update_padded(new_verts_padded=verts_ndc)

pytorch3d/renderer/points/rasterizer.py

@@ -10,6 +10,7 @@ from typing import NamedTuple, Optional, Tuple, Union
 
 import torch
 import torch.nn as nn
+from pytorch3d.renderer.cameras import try_get_projection_transform
 from pytorch3d.structures import Pointclouds
 
 from .rasterize_points import rasterize_points
@@ -103,12 +104,16 @@ class PointsRasterizer(nn.Module):
         pts_view = cameras.get_world_to_view_transform(**kwargs).transform_points(
             pts_world, eps=eps
         )
-        # view to NDC transform
         to_ndc_transform = cameras.get_ndc_camera_transform(**kwargs)
-        projection_transform = cameras.get_projection_transform(**kwargs).compose(
-            to_ndc_transform
-        )
-        pts_ndc = projection_transform.transform_points(pts_view, eps=eps)
+        projection_transform = try_get_projection_transform(cameras, kwargs)
+        if projection_transform is not None:
+            projection_transform = projection_transform.compose(to_ndc_transform)
+            pts_ndc = projection_transform.transform_points(pts_view, eps=eps)
+        else:
+            # Call transform_points instead of explicitly composing transforms to handle
+            # the case, where camera class does not have a projection matrix form.
+            pts_proj = cameras.transform_points(pts_world, eps=eps)
+            pts_ndc = to_ndc_transform.transform_points(pts_proj, eps=eps)
 
         pts_ndc[..., 2] = pts_view[..., 2]
         point_clouds = point_clouds.update_padded(pts_ndc)