File size: 2,519 Bytes
57746f1 |
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 |
import math
import torch
from dust3r.utils.geometry import inv
from src.utils.cuda_splatting import DummyCamera
def get_scaled_camera(ref_camera_extrinsics, target_camera_extrinsics, target_camera_intrinsics, scale, image_shape):
"""
get a scaled camera from a reference camera to a target camera
"""
# get extrinsics(target_camera to ref_camera)
target_camera_extrinsics = inv(ref_camera_extrinsics) @ target_camera_extrinsics
# scale translation
target_camera_extrinsics[:3, 3] = target_camera_extrinsics[:3, 3] * scale
# invert extrinsics(ref_camera to target_camera)
target_camera_extrinsics_inv = inv(target_camera_extrinsics)
# calculate fov
fovx = 2 * math.atan(image_shape[1] / (2 * target_camera_intrinsics[0, 0]))
fovy = 2 * math.atan(image_shape[0] / (2 * target_camera_intrinsics[1, 1]))
# return camera(numpy)
R = target_camera_extrinsics_inv[:3, :3].cpu().numpy().transpose() # R.transpose() : ref_camera_2_target_camera
T = target_camera_extrinsics_inv[:3, 3].cpu().numpy() # T : ref_camera_2_target_camera
image_shape = image_shape.cpu().numpy()
return DummyCamera(R, T, fovx, fovy, image_shape[1], image_shape[0])
def move_c2w_along_z(extrinsics: torch.Tensor, distance: float) -> torch.Tensor:
"""
向后移动多个 Camera-to-World (C2W) 矩阵，使相机沿各自 Z 轴方向远离原点。
参数:
extrinsics (torch.Tensor): 形状为 [N, 4, 4] 的张量，包含 N 个 C2W 矩阵。
distance (float): 向后移动的距离。
返回:
torch.Tensor: 更新后的 C2W 矩阵，形状与输入相同。
"""
# 确保输入是一个四维矩阵，且最后一维是 4x4
assert extrinsics.dim() == 3 and extrinsics.shape[1:] == (4, 4), \
"输入的 extrinsics 必须是形状为 [N, 4, 4] 的张量"
# 创建一个拷贝以免修改原矩阵
updated_extrinsics = extrinsics.clone()
# 遍历每个 C2W 矩阵
for i in range(updated_extrinsics.shape[0]):
# 提取旋转矩阵 R 和平移向量 t
R = updated_extrinsics[i, :3, :3] # 形状为 [3, 3]
t = updated_extrinsics[i, :3, 3] # 形状为 [3]
# 获取相机的 Z 轴方向（第三列）
z_axis = R[:, 2] # 形状为 [3]
# 计算新的平移向量，沿 Z 轴方向向后移动
t_new = t - distance * z_axis
# 更新 C2W 矩阵的平移部分
updated_extrinsics[i, :3, 3] = t_new
return updated_extrinsics
|