multigpu mesh rendering fixes

Summary:
Small fix and updated tests for multigpu rendering case.

This resolves the issue seen in: https://github.com/facebookresearch/pytorch3d/issues/401

Reviewed By: gkioxari

Differential Revision: D24314681

fbshipit-source-id: 84c5a5359844c77518b48044001daa9a86f3c43a

tests/test_render_meshes.py

@@ -1042,67 +1042,3 @@ class TestRenderMeshes(TestCaseMixin, unittest.TestCase):
                 )
 
             self.assertClose(rgb, image_ref, atol=0.05)
-
-    def test_to(self):
-        # Test moving all the tensors in the renderer to a new device
-        # to support multigpu rendering.
-        device1 = torch.device("cpu")
-
-        R, T = look_at_view_transform(1500, 0.0, 0.0)
-
-        # Init shader settings
-        materials = Materials(device=device1)
-        lights = PointLights(device=device1)
-        lights.location = torch.tensor([0.0, 0.0, +1000.0], device=device1)[None]
-
-        raster_settings = RasterizationSettings(
-            image_size=256, blur_radius=0.0, faces_per_pixel=1
-        )
-        cameras = FoVPerspectiveCameras(
-            device=device1, R=R, T=T, aspect_ratio=1.0, fov=60.0, zfar=100
-        )
-        rasterizer = MeshRasterizer(cameras=cameras, raster_settings=raster_settings)
-
-        blend_params = BlendParams(
-            1e-4,
-            1e-4,
-            background_color=torch.zeros(3, dtype=torch.float32, device=device1),
-        )
-
-        shader = SoftPhongShader(
-            lights=lights,
-            cameras=cameras,
-            materials=materials,
-            blend_params=blend_params,
-        )
-        renderer = MeshRenderer(rasterizer=rasterizer, shader=shader)
-
-        def _check_props_on_device(renderer, device):
-            self.assertEqual(renderer.rasterizer.cameras.device, device)
-            self.assertEqual(renderer.shader.cameras.device, device)
-            self.assertEqual(renderer.shader.lights.device, device)
-            self.assertEqual(renderer.shader.lights.ambient_color.device, device)
-            self.assertEqual(renderer.shader.materials.device, device)
-            self.assertEqual(renderer.shader.materials.ambient_color.device, device)
-
-        mesh = ico_sphere(2, device1)
-        verts_padded = mesh.verts_padded()
-        textures = TexturesVertex(
-            verts_features=torch.ones_like(verts_padded, device=device1)
-        )
-        mesh.textures = textures
-        _check_props_on_device(renderer, device1)
-
-        # Test rendering on cpu
-        output_images = renderer(mesh)
-        self.assertEqual(output_images.device, device1)
-
-        # Move renderer and mesh to another device and re render
-        # This also tests that background_color is correctly moved to
-        # the new device
-        device2 = torch.device("cuda:0")
-        renderer.to(device2)
-        mesh = mesh.to(device2)
-        _check_props_on_device(renderer, device2)
-        output_images = renderer(mesh)
-        self.assertEqual(output_images.device, device2)