Increase code coverage of shader

Summary: Increase code coverage of shader and re-include them in code coverage test

Reviewed By: nikhilaravi

Differential Revision: D29097503

fbshipit-source-id: 2791989ee1562cfa193f3addea0ce72d6840614a

pytorch3d/renderer/mesh/shader.py

@@ -26,7 +26,7 @@ from .shading import flat_shading, gouraud_shading, phong_shading
 #     - blend colors across top K faces per pixel.
 
 
-class HardPhongShader(nn.Module):  # pragma: no cover
+class HardPhongShader(nn.Module):
     """
     Per pixel lighting - the lighting model is applied using the interpolated
     coordinates and normals for each pixel. The blending function hard assigns
@@ -58,7 +58,8 @@ class HardPhongShader(nn.Module):  # pragma: no cover
 
     def to(self, device: Device):
         # Manually move to device modules which are not subclasses of nn.Module
-        self.cameras = self.cameras.to(device)
+        if self.cameras is not None:
+            self.cameras = self.cameras.to(device)
         self.materials = self.materials.to(device)
         self.lights = self.lights.to(device)
         return self
@@ -86,7 +87,7 @@ class HardPhongShader(nn.Module):  # pragma: no cover
         return images
 
 
-class SoftPhongShader(nn.Module):  # pragma: no cover
+class SoftPhongShader(nn.Module):
     """
     Per pixel lighting - the lighting model is applied using the interpolated
     coordinates and normals for each pixel. The blending function returns the
@@ -118,7 +119,8 @@ class SoftPhongShader(nn.Module):  # pragma: no cover
 
     def to(self, device: Device):
         # Manually move to device modules which are not subclasses of nn.Module
-        self.cameras = self.cameras.to(device)
+        if self.cameras is not None:
+            self.cameras = self.cameras.to(device)
         self.materials = self.materials.to(device)
         self.lights = self.lights.to(device)
         return self
@@ -150,7 +152,7 @@ class SoftPhongShader(nn.Module):  # pragma: no cover
         return images
 
 
-class HardGouraudShader(nn.Module):  # pragma: no cover
+class HardGouraudShader(nn.Module):
     """
     Per vertex lighting - the lighting model is applied to the vertex colors and
     the colors are then interpolated using the barycentric coordinates to
@@ -183,7 +185,8 @@ class HardGouraudShader(nn.Module):  # pragma: no cover
 
     def to(self, device: Device):
         # Manually move to device modules which are not subclasses of nn.Module
-        self.cameras = self.cameras.to(device)
+        if self.cameras is not None:
+            self.cameras = self.cameras.to(device)
         self.materials = self.materials.to(device)
         self.lights = self.lights.to(device)
         return self
@@ -214,7 +217,7 @@ class HardGouraudShader(nn.Module):  # pragma: no cover
         return images
 
 
-class SoftGouraudShader(nn.Module):  # pragma: no cover
+class SoftGouraudShader(nn.Module):
     """
     Per vertex lighting - the lighting model is applied to the vertex colors and
     the colors are then interpolated using the barycentric coordinates to
@@ -247,7 +250,8 @@ class SoftGouraudShader(nn.Module):  # pragma: no cover
 
     def to(self, device: Device):
         # Manually move to device modules which are not subclasses of nn.Module
-        self.cameras = self.cameras.to(device)
+        if self.cameras is not None:
+            self.cameras = self.cameras.to(device)
         self.materials = self.materials.to(device)
         self.lights = self.lights.to(device)
         return self
@@ -277,7 +281,7 @@ class SoftGouraudShader(nn.Module):  # pragma: no cover
 
 def TexturedSoftPhongShader(
     device: Device = "cpu", cameras=None, lights=None, materials=None, blend_params=None
-):  # pragma: no cover
+):
     """
     TexturedSoftPhongShader class has been DEPRECATED. Use SoftPhongShader instead.
     Preserving TexturedSoftPhongShader as a function for backwards compatibility.
@@ -296,7 +300,7 @@ def TexturedSoftPhongShader(
     )
 
 
-class HardFlatShader(nn.Module):  # pragma: no cover
+class HardFlatShader(nn.Module):
     """
     Per face lighting - the lighting model is applied using the average face
     position and the face normal. The blending function hard assigns
@@ -328,7 +332,8 @@ class HardFlatShader(nn.Module):  # pragma: no cover
 
     def to(self, device: Device):
         # Manually move to device modules which are not subclasses of nn.Module
-        self.cameras = self.cameras.to(device)
+        if self.cameras is not None:
+            self.cameras = self.cameras.to(device)
         self.materials = self.materials.to(device)
         self.lights = self.lights.to(device)
         return self
@@ -355,7 +360,7 @@ class HardFlatShader(nn.Module):  # pragma: no cover
         return images
 
 
-class SoftSilhouetteShader(nn.Module):  # pragma: no cover
+class SoftSilhouetteShader(nn.Module):
     """
     Calculate the silhouette by blending the top K faces for each pixel based
     on the 2d euclidean distance of the center of the pixel to the mesh face.

tests/test_shader.py

@@ -0,0 +1,87 @@
+# Copyright (c) Facebook, Inc. and its affiliates. All rights reserved.
+
+import unittest
+
+import torch
+from common_testing import TestCaseMixin
+from pytorch3d.renderer.cameras import (
+    look_at_view_transform,
+    PerspectiveCameras,
+)
+from pytorch3d.renderer.mesh.rasterizer import Fragments
+from pytorch3d.renderer.mesh.shader import (
+    HardFlatShader,
+    HardGouraudShader,
+    HardPhongShader,
+    SoftPhongShader,
+)
+from pytorch3d.structures.meshes import Meshes
+
+
+class TestShader(TestCaseMixin, unittest.TestCase):
+    def test_to(self):
+        cpu_device = torch.device("cpu")
+        cuda_device = torch.device("cuda")
+
+        R, T = look_at_view_transform()
+
+        shader_classes = [
+            HardFlatShader,
+            HardGouraudShader,
+            HardPhongShader,
+            SoftPhongShader,
+        ]
+
+        for shader_class in shader_classes:
+            for cameras_class in (None, PerspectiveCameras):
+                if cameras_class is None:
+                    cameras = None
+                else:
+                    cameras = PerspectiveCameras(device=cpu_device, R=R, T=T)
+
+                cpu_shader = shader_class(device=cpu_device, cameras=cameras)
+                if cameras is None:
+                    self.assertIsNone(cpu_shader.cameras)
+                else:
+                    self.assertEqual(cpu_device, cpu_shader.cameras.device)
+                self.assertEqual(cpu_device, cpu_shader.materials.device)
+                self.assertEqual(cpu_device, cpu_shader.lights.device)
+
+                cuda_shader = cpu_shader.to(cuda_device)
+                self.assertIs(cpu_shader, cuda_shader)
+                if cameras is None:
+                    self.assertIsNone(cuda_shader.cameras)
+                else:
+                    self.assertEqual(cuda_device, cuda_shader.cameras.device)
+                self.assertEqual(cuda_device, cuda_shader.materials.device)
+                self.assertEqual(cuda_device, cuda_shader.lights.device)
+
+    def test_cameras_check(self):
+        verts = torch.tensor(
+            [[-1, -1, 0], [1, -1, 1], [1, 1, 0], [-1, 1, 1]], dtype=torch.float32
+        )
+        faces = torch.tensor([[0, 1, 2], [2, 3, 0]], dtype=torch.int64)
+        meshes = Meshes(verts=[verts], faces=[faces])
+
+        pix_to_face = torch.tensor([0, 1], dtype=torch.int64).view(1, 1, 1, 2)
+        barycentric_coords = torch.tensor(
+            [[0.1, 0.2, 0.7], [0.3, 0.5, 0.2]], dtype=torch.float32
+        ).view(1, 1, 1, 2, -1)
+        fragments = Fragments(
+            pix_to_face=pix_to_face,
+            bary_coords=barycentric_coords,
+            zbuf=torch.ones_like(pix_to_face),
+            dists=torch.ones_like(pix_to_face),
+        )
+        shader_classes = [
+            HardFlatShader,
+            HardGouraudShader,
+            HardPhongShader,
+            SoftPhongShader,
+        ]
+
+        for shader_class in shader_classes:
+            shader = shader_class()
+
+            with self.assertRaises(ValueError):
+                shader(fragments, meshes)