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Summary: Plotly viewing from a specific camera location requires converting that location in to an (eye, at, up) specification. There may be other reasons to want to do this as well. I create a separate utility function for it. I envisage more such utility functions for manipulating camera information, so I create a separate camera_utils.py file for such things. Reviewed By: nikhilaravi Differential Revision: D25981184 fbshipit-source-id: 0947bf98b212676c021f2fddf775bf436dee3487
52 lines
2.0 KiB
Python
52 lines
2.0 KiB
Python
# Copyright (c) Facebook, Inc. and its affiliates. All rights reserved.
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import unittest
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import torch
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from common_testing import TestCaseMixin
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from pytorch3d.renderer.camera_utils import camera_to_eye_at_up
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from pytorch3d.renderer.cameras import PerspectiveCameras, look_at_view_transform
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from torch.nn.functional import normalize
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class TestCameraUtils(TestCaseMixin, unittest.TestCase):
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def setUp(self) -> None:
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torch.manual_seed(42)
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def test_invert_eye_at_up(self):
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# Generate random cameras and check we can reconstruct their eye, at,
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# and up vectors.
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N = 13
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eye = torch.rand(N, 3)
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at = torch.rand(N, 3)
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up = torch.rand(N, 3)
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R, T = look_at_view_transform(eye=eye, at=at, up=up)
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cameras = PerspectiveCameras(R=R, T=T)
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eye2, at2, up2 = camera_to_eye_at_up(cameras.get_world_to_view_transform())
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# The retrieved eye matches
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self.assertClose(eye, eye2, atol=1e-5)
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# at-eye as retrieved must be a vector in the same direction as
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# the original.
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self.assertClose(normalize(at - eye), normalize(at2 - eye2))
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# The up vector as retrieved should be rotated the same amount
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# around at-eye as the original. The component in the at-eye
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# direction is unimportant, as is the length.
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# So check that (up x (at-eye)) as retrieved is in the same
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# direction as its original value.
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up_check = torch.cross(up, at - eye, dim=-1)
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up_check2 = torch.cross(up2, at - eye, dim=-1)
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self.assertClose(normalize(up_check), normalize(up_check2))
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# Master check that we get the same camera if we reinitialise.
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R2, T2 = look_at_view_transform(eye=eye2, at=at2, up=up2)
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cameras2 = PerspectiveCameras(R=R2, T=T2)
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cam_trans = cameras.get_world_to_view_transform()
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cam_trans2 = cameras2.get_world_to_view_transform()
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self.assertClose(cam_trans.get_matrix(), cam_trans2.get_matrix(), atol=1e-5)
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