File size: 8,476 Bytes
f12ab4c
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
# Copyright (c) 2020, NVIDIA CORPORATION.  All rights reserved.
#
# NVIDIA CORPORATION and its licensors retain all intellectual property
# and proprietary rights in and to this software, related documentation
# and any modifications thereto.  Any use, reproduction, disclosure or
# distribution of this software and related documentation without an express
# license agreement from NVIDIA CORPORATION is strictly prohibited.

import argparse
import os
import pathlib
import numpy as np
import torch

import util

import nvdiffrast.torch as dr

#----------------------------------------------------------------------------
# Helpers.

def transform_pos(mtx, pos):
    t_mtx = torch.from_numpy(mtx).cuda() if isinstance(mtx, np.ndarray) else mtx
    posw = torch.cat([pos, torch.ones([pos.shape[0], 1]).cuda()], axis=1)
    return torch.matmul(posw, t_mtx.t())[None, ...]

def render(glctx, mtx, pos, pos_idx, uv, uv_idx, tex, resolution, enable_mip, max_mip_level):
    pos_clip = transform_pos(mtx, pos)
    rast_out, rast_out_db = dr.rasterize(glctx, pos_clip, pos_idx, resolution=[resolution, resolution])

    if enable_mip:
        texc, texd = dr.interpolate(uv[None, ...], rast_out, uv_idx, rast_db=rast_out_db, diff_attrs='all')
        color = dr.texture(tex[None, ...], texc, texd, filter_mode='linear-mipmap-linear', max_mip_level=max_mip_level)
    else:
        texc, _ = dr.interpolate(uv[None, ...], rast_out, uv_idx)
        color = dr.texture(tex[None, ...], texc, filter_mode='linear')

    color = color * torch.clamp(rast_out[..., -1:], 0, 1) # Mask out background.
    return color

#----------------------------------------------------------------------------

def fit_earth(max_iter          = 20000,
              log_interval      = 10,
              display_interval  = None,
              display_res       = 1024,
              enable_mip        = True,
              res               = 512,
              ref_res           = 4096,
              lr_base           = 1e-2,
              lr_ramp           = 0.1,
              out_dir           = None,
              log_fn            = None,
              texsave_interval  = None,
              texsave_fn        = None,
              imgsave_interval  = None,
              imgsave_fn        = None):

    log_file = None
    if out_dir:
        os.makedirs(out_dir, exist_ok=True)
        if log_fn:
            log_file = open(out_dir + '/' + log_fn, 'wt')
    else:
        imgsave_interval, texsave_interval = None, None
    
    # Mesh and texture adapted from "3D Earth Photorealistic 2K" model at
    # https://www.turbosquid.com/3d-models/3d-realistic-earth-photorealistic-2k-1279125
    datadir = f'{pathlib.Path(__file__).absolute().parents[1]}/data'
    with np.load(f'{datadir}/earth.npz') as f:
        pos_idx, pos, uv_idx, uv, tex = f.values()
    tex = tex.astype(np.float32)/255.0
    max_mip_level = 9 # Texture is a 4x3 atlas of 512x512 maps.
    print("Mesh has %d triangles and %d vertices." % (pos_idx.shape[0], pos.shape[0]))

    # Some input geometry contains vertex positions in (N, 4) (with v[:,3]==1).  Drop
    # the last column in that case.
    if pos.shape[1] == 4: pos = pos[:, 0:3]

    # Create position/triangle index tensors
    pos_idx = torch.from_numpy(pos_idx.astype(np.int32)).cuda()
    vtx_pos = torch.from_numpy(pos.astype(np.float32)).cuda()
    uv_idx  = torch.from_numpy(uv_idx.astype(np.int32)).cuda()
    vtx_uv  = torch.from_numpy(uv.astype(np.float32)).cuda()

    tex     = torch.from_numpy(tex.astype(np.float32)).cuda()
    tex_opt = torch.full(tex.shape, 0.2, device='cuda', requires_grad=True)
    glctx = dr.RasterizeGLContext()

    ang = 0.0

    # Adam optimizer for texture with a learning rate ramp.
    optimizer    = torch.optim.Adam([tex_opt], lr=lr_base)
    scheduler    = torch.optim.lr_scheduler.LambdaLR(optimizer, lr_lambda=lambda x: lr_ramp**(float(x)/float(max_iter)))

    # Render.
    ang = 0.0
    texloss_avg = []
    for it in range(max_iter + 1):
        # Random rotation/translation matrix for optimization.
        r_rot = util.random_rotation_translation(0.25)

        # Smooth rotation for display.
        a_rot = np.matmul(util.rotate_x(-0.4), util.rotate_y(ang))
        dist = np.random.uniform(0.0, 48.5)

        # Modelview and modelview + projection matrices.
        proj  = util.projection(x=0.4, n=1.0, f=200.0)
        r_mv  = np.matmul(util.translate(0, 0, -1.5 - dist), r_rot)
        r_mvp = np.matmul(proj, r_mv).astype(np.float32)
        a_mv  = np.matmul(util.translate(0, 0, -3.5), a_rot)
        a_mvp = np.matmul(proj, a_mv).astype(np.float32)

        # Measure texture-space RMSE loss
        with torch.no_grad():
            texmask = torch.zeros_like(tex)
            tr = tex.shape[1]//4
            texmask[tr+13:2*tr-13, 25:-25, :] += 1.0
            texmask[25:-25, tr+13:2*tr-13, :] += 1.0
            # Measure only relevant portions of texture when calculating texture
            # PSNR.
            texloss = (torch.sum(texmask * (tex - tex_opt)**2)/torch.sum(texmask))**0.5 # RMSE within masked area.
            texloss_avg.append(float(texloss))

        # Render reference and optimized frames. Always enable mipmapping for reference.
        color = render(glctx, r_mvp, vtx_pos, pos_idx, vtx_uv, uv_idx, tex, ref_res, True, max_mip_level)
        color_opt = render(glctx, r_mvp, vtx_pos, pos_idx, vtx_uv, uv_idx, tex_opt, res, enable_mip, max_mip_level)

        # Reduce the reference to correct size.
        while color.shape[1] > res:
            color = util.bilinear_downsample(color)

        # Compute loss and perform a training step.
        loss = torch.mean((color - color_opt)**2) # L2 pixel loss.
        optimizer.zero_grad()
        loss.backward()
        optimizer.step()
        scheduler.step()

        # Print/save log.
        if log_interval and (it % log_interval == 0):
            texloss_val = np.mean(np.asarray(texloss_avg))
            texloss_avg = []
            psnr = -10.0 * np.log10(texloss_val**2) # PSNR based on average RMSE.
            s = "iter=%d,loss=%f,psnr=%f" % (it, texloss_val, psnr)
            print(s)
            if log_file:
                log_file.write(s + '\n')

        # Show/save image.
        display_image = display_interval and (it % display_interval == 0)
        save_image = imgsave_interval and (it % imgsave_interval == 0)
        save_texture = texsave_interval and (it % texsave_interval) == 0

        if display_image or save_image:
            ang = ang + 0.1

            with torch.no_grad():
                result_image = render(glctx, a_mvp, vtx_pos, pos_idx, vtx_uv, uv_idx, tex_opt, res, enable_mip, max_mip_level)[0].cpu().numpy()

                if display_image:
                    util.display_image(result_image, size=display_res, title='%d / %d' % (it, max_iter))
                if save_image:
                    util.save_image(out_dir + '/' + (imgsave_fn % it), result_image)

                if save_texture:
                    texture = tex_opt.cpu().numpy()[::-1]
                    util.save_image(out_dir + '/' + (texsave_fn % it), texture)


    # Done.
    if log_file:
        log_file.close()

#----------------------------------------------------------------------------

def main():
    parser = argparse.ArgumentParser(description='Earth texture fitting example')
    parser.add_argument('--outdir', help='Specify output directory', default='')
    parser.add_argument('--mip', action='store_true', default=False)
    parser.add_argument('--display-interval', type=int, default=0)
    parser.add_argument('--max-iter', type=int, default=10000)
    args = parser.parse_args()

    # Set up logging.
    if args.outdir:
        ms = 'mip' if args.mip else 'nomip'
        out_dir = f'{args.outdir}/earth_{ms}'
        print (f'Saving results under {out_dir}')
    else:
        out_dir = None
        print ('No output directory specified, not saving log or images')

    # Run.
    fit_earth(max_iter=args.max_iter, log_interval=10, display_interval=args.display_interval, enable_mip=args.mip, out_dir=out_dir, log_fn='log.txt', texsave_interval=1000, texsave_fn='tex_%06d.png', imgsave_interval=1000, imgsave_fn='img_%06d.png')

    # Done.
    print("Done.")

#----------------------------------------------------------------------------

if __name__ == "__main__":
    main()

#----------------------------------------------------------------------------