Files
Magic123/nerf/provider.py
Guocheng Qian 13e18567fa first commit
2023-08-02 19:51:43 -07:00

330 lines
12 KiB
Python

import random
import numpy as np
from scipy.spatial.transform import Slerp, Rotation
import torch
import torch.nn.functional as F
from torch.utils.data import DataLoader
from .utils import get_rays, safe_normalize
DIR_COLORS = np.array([
[255, 0, 0, 255], # front
[0, 255, 0, 255], # side
[0, 0, 255, 255], # back
[255, 255, 0, 255], # side
[255, 0, 255, 255], # overhead
[0, 255, 255, 255], # bottom
], dtype=np.uint8)
def visualize_poses(poses, dirs, size=0.1):
# poses: [B, 4, 4], dirs: [B]
import trimesh
axes = trimesh.creation.axis(axis_length=4)
sphere = trimesh.creation.icosphere(radius=1)
objects = [axes, sphere]
for pose, dir in zip(poses, dirs):
# a camera is visualized with 8 line segments.
pos = pose[:3, 3]
a = pos + size * pose[:3, 0] + size * pose[:3, 1] - size * pose[:3, 2]
b = pos - size * pose[:3, 0] + size * pose[:3, 1] - size * pose[:3, 2]
c = pos - size * pose[:3, 0] - size * pose[:3, 1] - size * pose[:3, 2]
d = pos + size * pose[:3, 0] - size * pose[:3, 1] - size * pose[:3, 2]
segs = np.array([[pos, a], [pos, b], [pos, c], [pos, d], [a, b], [b, c], [c, d], [d, a]])
segs = trimesh.load_path(segs)
# different color for different dirs
segs.colors = DIR_COLORS[[dir]].repeat(len(segs.entities), 0)
objects.append(segs)
trimesh.Scene(objects).show()
def get_view_direction(thetas, phis, overhead, front):
# phis [B,]; thetas: [B,]
# front = 0 [0, front)
# side (right) = 1 [front, 180)
# back = 2 [180, 180+front)
# side (left) = 3 [180+front, 360)
# top = 4 [0, overhead]
# bottom = 5 [180-overhead, 180]
res = torch.zeros(thetas.shape[0], dtype=torch.long)
# first determine by phis
phis = phis % (2 * np.pi)
res[(phis < front / 2) | (phis >= 2 * np.pi - front / 2)] = 0
res[(phis >= front / 2) & (phis < np.pi - front / 2)] = 1
res[(phis >= np.pi - front / 2) & (phis < np.pi + front / 2)] = 2
res[(phis >= np.pi + front / 2) & (phis < 2 * np.pi - front / 2)] = 3
# override by thetas
res[thetas <= overhead] = 4
res[thetas >= (np.pi - overhead)] = 5
return res
def rand_poses(size, device, opt, radius_range=[1, 1.5], theta_range=[0, 120], phi_range=[0, 360], return_dirs=False, angle_overhead=30, angle_front=60, uniform_sphere_rate=0.5):
''' generate random poses from an orbit camera
Args:
size: batch size of generated poses.
device: where to allocate the output.
radius: camera radius
theta_range: [min, max], should be in [0, pi]
phi_range: [min, max], should be in [0, 2 * pi]
Return:
poses: [size, 4, 4]
'''
theta_range = np.array(theta_range) / 180 * np.pi
phi_range = np.array(phi_range) / 180 * np.pi
angle_overhead = angle_overhead / 180 * np.pi
angle_front = angle_front / 180 * np.pi
radius = torch.rand(size, device=device) * (radius_range[1] - radius_range[0]) + radius_range[0]
if random.random() < uniform_sphere_rate:
unit_centers = F.normalize(
torch.stack([
(torch.rand(size, device=device) - 0.5) * 2.0,
torch.rand(size, device=device),
(torch.rand(size, device=device) - 0.5) * 2.0,
], dim=-1), p=2, dim=1
)
thetas = torch.acos(unit_centers[:,1])
phis = torch.atan2(unit_centers[:,0], unit_centers[:,2])
phis[phis < 0] += 2 * np.pi
centers = unit_centers * radius.unsqueeze(-1)
else:
thetas = torch.rand(size, device=device) * (theta_range[1] - theta_range[0]) + theta_range[0]
phis = torch.rand(size, device=device) * (phi_range[1] - phi_range[0]) + phi_range[0]
phis[phis < 0] += 2 * np.pi
centers = torch.stack([
radius * torch.sin(thetas) * torch.sin(phis),
radius * torch.cos(thetas),
radius * torch.sin(thetas) * torch.cos(phis),
], dim=-1) # [B, 3]
targets = 0
# jitters
if opt.jitter_pose:
jit_center = opt.jitter_center # 0.015 # was 0.2
jit_target = opt.jitter_target
centers += torch.rand_like(centers) * jit_center - jit_center/2.0
targets += torch.randn_like(centers) * jit_target
# lookat
forward_vector = safe_normalize(centers - targets)
up_vector = torch.FloatTensor([0, 1, 0]).to(device).unsqueeze(0).repeat(size, 1)
right_vector = safe_normalize(torch.cross(forward_vector, up_vector, dim=-1))
if opt.jitter_pose:
up_noise = torch.randn_like(up_vector) * opt.jitter_up
else:
up_noise = 0
up_vector = safe_normalize(torch.cross(right_vector, forward_vector, dim=-1) + up_noise)
poses = torch.eye(4, dtype=torch.float, device=device).unsqueeze(0).repeat(size, 1, 1)
poses[:, :3, :3] = torch.stack((right_vector, up_vector, forward_vector), dim=-1)
poses[:, :3, 3] = centers
if return_dirs:
dirs = get_view_direction(thetas, phis, angle_overhead, angle_front)
else:
dirs = None
# back to degree
thetas = thetas / np.pi * 180
phis = phis / np.pi * 180
return poses, dirs, thetas, phis, radius
def circle_poses(device, radius=torch.tensor([3.2]), theta=torch.tensor([60]), phi=torch.tensor([0]), return_dirs=False, angle_overhead=30, angle_front=60):
theta = theta / 180 * np.pi
phi = phi / 180 * np.pi
angle_overhead = angle_overhead / 180 * np.pi
angle_front = angle_front / 180 * np.pi
centers = torch.stack([
radius * torch.sin(theta) * torch.sin(phi),
radius * torch.cos(theta),
radius * torch.sin(theta) * torch.cos(phi),
], dim=-1) # [B, 3]
# lookat
forward_vector = safe_normalize(centers)
up_vector = torch.FloatTensor([0, 1, 0]).to(device).unsqueeze(0).repeat(len(centers), 1)
right_vector = safe_normalize(torch.cross(forward_vector, up_vector, dim=-1))
up_vector = safe_normalize(torch.cross(right_vector, forward_vector, dim=-1))
poses = torch.eye(4, dtype=torch.float, device=device).unsqueeze(0).repeat(len(centers), 1, 1)
poses[:, :3, :3] = torch.stack((right_vector, up_vector, forward_vector), dim=-1)
poses[:, :3, 3] = centers
if return_dirs:
dirs = get_view_direction(theta, phi, angle_overhead, angle_front)
else:
dirs = None
return poses, dirs
class NeRFDataset:
def __init__(self, opt, device, type='train', H=256, W=256, size=100):
super().__init__()
self.opt = opt
self.device = device
self.type = type # train, val, test
self.H = H
self.W = W
self.size = size
self.training = self.type in ['train', 'all']
self.cx = self.H / 2
self.cy = self.W / 2
self.near = self.opt.min_near
self.far = 1000 # infinite
# [debug] visualize poses
# poses, dirs, _, _, _ = rand_poses(100, self.device, opt, radius_range=self.opt.radius_range, angle_overhead=self.opt.angle_overhead, angle_front=self.opt.angle_front, jitter=self.opt.jitter_pose, uniform_sphere_rate=1)
# visualize_poses(poses.detach().cpu().numpy(), dirs.detach().cpu().numpy())
def get_default_view_data(self):
H = int(self.opt.known_view_scale * self.H)
W = int(self.opt.known_view_scale * self.W)
cx = H / 2
cy = W / 2
radii = torch.FloatTensor(self.opt.ref_radii).to(self.device)
thetas = torch.FloatTensor(self.opt.ref_polars).to(self.device)
phis = torch.FloatTensor(self.opt.ref_azimuths).to(self.device)
poses, dirs = circle_poses(self.device, radius=radii, theta=thetas, phi=phis, return_dirs=True, angle_overhead=self.opt.angle_overhead, angle_front=self.opt.angle_front)
fov = self.opt.default_fovy
focal = H / (2 * np.tan(np.deg2rad(fov) / 2))
intrinsics = np.array([focal, focal, cx, cy])
projection = torch.tensor([
[2*focal/W, 0, 0, 0],
[0, -2*focal/H, 0, 0],
[0, 0, -(self.far+self.near)/(self.far-self.near), -(2*self.far*self.near)/(self.far-self.near)],
[0, 0, -1, 0]
], dtype=torch.float32, device=self.device).unsqueeze(0).repeat(len(radii), 1, 1)
mvp = projection @ torch.inverse(poses) # [B, 4, 4]
# sample a low-resolution but full image
rays = get_rays(poses, intrinsics, H, W, -1)
data = {
'H': H,
'W': W,
'rays_o': rays['rays_o'],
'rays_d': rays['rays_d'],
'dir': dirs,
'mvp': mvp,
'polar': self.opt.ref_polars,
'azimuth': self.opt.ref_azimuths,
'radius': self.opt.ref_radii,
}
return data
def collate(self, index):
B = len(index)
if self.training:
# random pose on the fly
poses, dirs, thetas, phis, radius = rand_poses(B, self.device, self.opt, radius_range=self.opt.radius_range, theta_range=self.opt.theta_range, phi_range=self.opt.phi_range, return_dirs=True, angle_overhead=self.opt.angle_overhead, angle_front=self.opt.angle_front, uniform_sphere_rate=self.opt.uniform_sphere_rate)
# random focal
fov = random.random() * (self.opt.fovy_range[1] - self.opt.fovy_range[0]) + self.opt.fovy_range[0]
elif self.type == 'six_views':
# six views
thetas_six = [90]*4 + [1e-6] + [180]
phis_six = [0, 90, 180, -90, 0, 0]
thetas = torch.FloatTensor([thetas_six[index[0]]]).to(self.device)
phis = torch.FloatTensor([phis_six[index[0]]]).to(self.device)
radius = torch.FloatTensor([self.opt.default_radius]).to(self.device)
poses, dirs = circle_poses(self.device, radius=radius, theta=thetas, phi=phis, return_dirs=True, angle_overhead=self.opt.angle_overhead, angle_front=self.opt.angle_front)
# fixed focal
fov = self.opt.default_fovy
else:
# circle pose
thetas = torch.FloatTensor([self.opt.default_polar]).to(self.device)
phis = torch.FloatTensor([(index[0] / self.size) * 360]).to(self.device)
radius = torch.FloatTensor([self.opt.default_radius]).to(self.device)
poses, dirs = circle_poses(self.device, radius=radius, theta=thetas, phi=phis, return_dirs=True, angle_overhead=self.opt.angle_overhead, angle_front=self.opt.angle_front)
# fixed focal
fov = self.opt.default_fovy
focal = self.H / (2 * np.tan(np.deg2rad(fov) / 2))
intrinsics = np.array([focal, focal, self.cx, self.cy])
projection = torch.tensor([
[2*focal/self.W, 0, 0, 0],
[0, -2*focal/self.H, 0, 0],
[0, 0, -(self.far+self.near)/(self.far-self.near), -(2*self.far*self.near)/(self.far-self.near)],
[0, 0, -1, 0]
], dtype=torch.float32, device=self.device).unsqueeze(0)
mvp = projection @ torch.inverse(poses) # [1, 4, 4]
# sample a low-resolution but full image
rays = get_rays(poses, intrinsics, self.H, self.W, -1)
# delta polar/azimuth/radius to default view
delta_polar = thetas - self.opt.default_polar
delta_azimuth = phis - self.opt.default_azimuth
delta_azimuth[delta_azimuth > 180] -= 360 # range in [-180, 180]
delta_radius = radius - self.opt.default_radius
data = {
'H': self.H,
'W': self.W,
'rays_o': rays['rays_o'],
'rays_d': rays['rays_d'],
'dir': dirs,
'mvp': mvp,
'polar': delta_polar,
'azimuth': delta_azimuth,
'radius': delta_radius,
}
return data
def dataloader(self, batch_size=None):
batch_size = batch_size or self.opt.batch_size
loader = DataLoader(list(range(self.size)), batch_size=batch_size, collate_fn=self.collate, shuffle=self.training, num_workers=0)
loader._data = self
return loader
def generate_grid_points(resolution=128, device='cuda'):
# resolution: number of points along each dimension
# Generate the grid points
x = torch.linspace(0, 1, resolution)
y = torch.linspace(0, 1, resolution)
z = torch.linspace(0, 1, resolution)
# Create the meshgrid
grid_x, grid_y, grid_z = torch.meshgrid(x, y, z)
# Flatten the grid points if needed
grid_points = torch.stack((grid_x.flatten(), grid_y.flatten(), grid_z.flatten()), dim=1).to(device)
return grid_points