pytorch3d/tests/test_camera_utils.py
Tim Hatch 34bbb3ad32 apply import merging for fbcode/vision/fair (2 of 2)
Summary:
Applies new import merging and sorting from µsort v1.0.

When merging imports, µsort will make a best-effort to move associated
comments to match merged elements, but there are known limitations due to
the diynamic nature of Python and developer tooling. These changes should
not produce any dangerous runtime changes, but may require touch-ups to
satisfy linters and other tooling.

Note that µsort uses case-insensitive, lexicographical sorting, which
results in a different ordering compared to isort. This provides a more
consistent sorting order, matching the case-insensitive order used when
sorting import statements by module name, and ensures that "frog", "FROG",
and "Frog" always sort next to each other.

For details on µsort's sorting and merging semantics, see the user guide:
https://usort.readthedocs.io/en/stable/guide.html#sorting

Reviewed By: bottler

Differential Revision: D35553814

fbshipit-source-id: be49bdb6a4c25264ff8d4db3a601f18736d17be1
2022-04-13 06:51:33 -07:00

168 lines
6.2 KiB
Python

# Copyright (c) Meta Platforms, Inc. and affiliates.
# All rights reserved.
#
# This source code is licensed under the BSD-style license found in the
# LICENSE file in the root directory of this source tree.
import unittest
from math import radians
import torch
from common_testing import TestCaseMixin
from pytorch3d.renderer.camera_utils import camera_to_eye_at_up, rotate_on_spot
from pytorch3d.renderer.cameras import (
get_world_to_view_transform,
look_at_view_transform,
PerspectiveCameras,
)
from pytorch3d.transforms import axis_angle_to_matrix
from torch.nn.functional import normalize
def _batched_dotprod(x: torch.Tensor, y: torch.Tensor):
"""
Takes two tensors of shape (N,3) and returns their batched
dot product along the last dimension as a tensor of shape
(N,).
"""
return torch.einsum("ij,ij->i", x, y)
class TestCameraUtils(TestCaseMixin, unittest.TestCase):
def setUp(self) -> None:
torch.manual_seed(42)
def test_invert_eye_at_up(self):
# Generate random cameras and check we can reconstruct their eye, at,
# and up vectors.
N = 13
eye = torch.rand(N, 3)
at = torch.rand(N, 3)
up = torch.rand(N, 3)
R, T = look_at_view_transform(eye=eye, at=at, up=up)
cameras = PerspectiveCameras(R=R, T=T)
eye2, at2, up2 = camera_to_eye_at_up(cameras.get_world_to_view_transform())
# The retrieved eye matches
self.assertClose(eye, eye2, atol=1e-5)
self.assertClose(cameras.get_camera_center(), eye)
# at-eye as retrieved must be a vector in the same direction as
# the original.
self.assertClose(normalize(at - eye), normalize(at2 - eye2))
# The up vector as retrieved should be rotated the same amount
# around at-eye as the original. The component in the at-eye
# direction is unimportant, as is the length.
# So check that (up x (at-eye)) as retrieved is in the same
# direction as its original value.
up_check = torch.cross(up, at - eye, dim=-1)
up_check2 = torch.cross(up2, at - eye, dim=-1)
self.assertClose(normalize(up_check), normalize(up_check2))
# Master check that we get the same camera if we reinitialise.
R2, T2 = look_at_view_transform(eye=eye2, at=at2, up=up2)
cameras2 = PerspectiveCameras(R=R2, T=T2)
cam_trans = cameras.get_world_to_view_transform()
cam_trans2 = cameras2.get_world_to_view_transform()
self.assertClose(cam_trans.get_matrix(), cam_trans2.get_matrix(), atol=1e-5)
def test_rotate_on_spot_yaw(self):
N = 14
eye = torch.rand(N, 3)
at = torch.rand(N, 3)
up = torch.rand(N, 3)
R, T = look_at_view_transform(eye=eye, at=at, up=up)
# Moving around the y axis looks left.
angles = torch.FloatTensor([0, -radians(10), 0])
rotation = axis_angle_to_matrix(angles)
R_rot, T_rot = rotate_on_spot(R, T, rotation)
eye_rot, at_rot, up_rot = camera_to_eye_at_up(
get_world_to_view_transform(R=R_rot, T=T_rot)
)
self.assertClose(eye, eye_rot, atol=1e-5)
# Make vectors pointing exactly left and up
left = torch.cross(up, at - eye, dim=-1)
left_rot = torch.cross(up_rot, at_rot - eye_rot, dim=-1)
fully_up = torch.cross(at - eye, left, dim=-1)
fully_up_rot = torch.cross(at_rot - eye_rot, left_rot, dim=-1)
# The up direction is unchanged
self.assertClose(normalize(fully_up), normalize(fully_up_rot), atol=1e-5)
# The camera has moved left
agree = _batched_dotprod(torch.cross(left, left_rot, dim=1), fully_up)
self.assertGreater(agree.min(), 0)
# Batch dimension for rotation
R_rot2, T_rot2 = rotate_on_spot(R, T, rotation.expand(N, 3, 3))
self.assertClose(R_rot, R_rot2)
self.assertClose(T_rot, T_rot2)
# No batch dimension for either
R_rot3, T_rot3 = rotate_on_spot(R[0], T[0], rotation)
self.assertClose(R_rot[:1], R_rot3)
self.assertClose(T_rot[:1], T_rot3)
# No batch dimension for R, T
R_rot4, T_rot4 = rotate_on_spot(R[0], T[0], rotation.expand(N, 3, 3))
self.assertClose(R_rot[:1].expand(N, 3, 3), R_rot4)
self.assertClose(T_rot[:1].expand(N, 3), T_rot4)
def test_rotate_on_spot_pitch(self):
N = 14
eye = torch.rand(N, 3)
at = torch.rand(N, 3)
up = torch.rand(N, 3)
R, T = look_at_view_transform(eye=eye, at=at, up=up)
# Moving around the x axis looks down.
angles = torch.FloatTensor([-radians(10), 0, 0])
rotation = axis_angle_to_matrix(angles)
R_rot, T_rot = rotate_on_spot(R, T, rotation)
eye_rot, at_rot, up_rot = camera_to_eye_at_up(
get_world_to_view_transform(R=R_rot, T=T_rot)
)
self.assertClose(eye, eye_rot, atol=1e-5)
# A vector pointing left is unchanged
left = torch.cross(up, at - eye, dim=-1)
left_rot = torch.cross(up_rot, at_rot - eye_rot, dim=-1)
self.assertClose(normalize(left), normalize(left_rot), atol=1e-5)
# The camera has moved down
fully_up = torch.cross(at - eye, left, dim=-1)
fully_up_rot = torch.cross(at_rot - eye_rot, left_rot, dim=-1)
agree = _batched_dotprod(torch.cross(fully_up, fully_up_rot, dim=1), left)
self.assertGreater(agree.min(), 0)
def test_rotate_on_spot_roll(self):
N = 14
eye = torch.rand(N, 3)
at = torch.rand(N, 3)
up = torch.rand(N, 3)
R, T = look_at_view_transform(eye=eye, at=at, up=up)
# Moving around the z axis rotates the image.
angles = torch.FloatTensor([0, 0, -radians(10)])
rotation = axis_angle_to_matrix(angles)
R_rot, T_rot = rotate_on_spot(R, T, rotation)
eye_rot, at_rot, up_rot = camera_to_eye_at_up(
get_world_to_view_transform(R=R_rot, T=T_rot)
)
self.assertClose(eye, eye_rot, atol=1e-5)
self.assertClose(normalize(at - eye), normalize(at_rot - eye), atol=1e-5)
# The camera has moved clockwise
agree = _batched_dotprod(torch.cross(up, up_rot, dim=1), at - eye)
self.assertGreater(agree.min(), 0)