How to apply uv_tex to obj file?

[jk4011]

First of all, thank you for this wonderful repository. I saved a lot of time and gained excellent results due to your effort.

But I've face a problem. It seems I can't apply uv_tex to obj file created by demo.py code. I found there is no vt(vertex texture) in obj file which is essential for uv_tex to be applied. Is uv_tex not purposed for obj, but for some other reasons?

Thank you for reading this question!

[brurpo]

This is Old, but if anyone wants it, I mad a quick edit to serialiation.py to include uvs in the obj

# coding: utf-8

__author__ = 'cleardusk'

import numpy as np
import os.path as osp
import scipy.io as sio
from utils.io import _load
from .tddfa_util import _to_ctype
from .functions import get_suffix

header_temp = """ply
format ascii 1.0
element vertex {}
property float x
property float y
property float z
element face {}
property list uchar int vertex_indices
end_header
"""
make_abs_path = lambda fn: osp.join(osp.dirname(osp.realpath(__file__)), fn)

def load_uv_coords(fp):
    C = sio.loadmat(fp)
    uv_coords = C['UV'].copy(order='C').astype(np.float32)
    return uv_coords

def process_uv(uv_coords, uv_h=256, uv_w=256):
    uv_coords[:, 0] = uv_coords[:, 0] * (uv_w - 1)
    uv_coords[:, 1] = uv_coords[:, 1] * (uv_h - 1)
    uv_coords[:, 1] = uv_h - uv_coords[:, 1] - 1
    uv_coords = np.hstack((uv_coords, np.zeros((uv_coords.shape[0], 1), dtype=np.float32)))  # add z
    return uv_coords

g_uv_coords = load_uv_coords(make_abs_path('../configs/BFM_UV.mat'))
indices = _load(make_abs_path('../configs/indices.npy'))  # todo: handle bfm_slim
g_uv_coords = g_uv_coords[indices, :]

def ser_to_ply_single(ver_lst, tri, height, wfp, reverse=True):
    suffix = get_suffix(wfp)

    for i, ver in enumerate(ver_lst):
        wfp_new = wfp.replace(suffix, f'_{i + 1}{suffix}')

        n_vertex = ver.shape[1]
        n_face = tri.shape[0]
        header = header_temp.format(n_vertex, n_face)

        with open(wfp_new, 'w') as f:
            f.write(header + '\n')
            for i in range(n_vertex):
                x, y, z = ver[:, i]
                if reverse:
                    f.write(f'{x:.2f} {height-y:.2f} {z:.2f}\n')
                else:
                    f.write(f'{x:.2f} {y:.2f} {z:.2f}\n')
            for i in range(n_face):
                idx1, idx2, idx3 = tri[i]  # m x 3
                if reverse:
                    f.write(f'3 {idx3} {idx2} {idx1}\n')
                else:
                    f.write(f'3 {idx1} {idx2} {idx3}\n')

        print(f'Dump tp {wfp_new}')

def ser_to_ply_multiple(ver_lst, tri, height, wfp, reverse=True):
    n_ply = len(ver_lst)  # count ply

    if n_ply <= 0:
        return

    n_vertex = ver_lst[0].shape[1]
    n_face = tri.shape[0]
    header = header_temp.format(n_vertex * n_ply, n_face * n_ply)

    with open(wfp, 'w') as f:
        f.write(header + '\n')

        for i in range(n_ply):
            ver = ver_lst[i]
            for j in range(n_vertex):
                x, y, z = ver[:, j]
                if reverse:
                    f.write(f'{x:.2f} {height - y:.2f} {z:.2f}\n')
                else:
                    f.write(f'{x:.2f} {y:.2f} {z:.2f}\n')

        for i in range(n_ply):
            offset = i * n_vertex
            for j in range(n_face):
                idx1, idx2, idx3 = tri[j]  # m x 3
                if reverse:
                    f.write(f'3 {idx3 + offset} {idx2 + offset} {idx1 + offset}\n')
                else:
                    f.write(f'3 {idx1 + offset} {idx2 + offset} {idx3 + offset}\n')

    print(f'Dump tp {wfp}')

def get_colors(img, ver):
    h, w, _ = img.shape
    ver[0, :] = np.minimum(np.maximum(ver[0, :], 0), w - 1)  # x
    ver[1, :] = np.minimum(np.maximum(ver[1, :], 0), h - 1)  # y
    ind = np.round(ver).astype(np.int32)
    colors = img[ind[1, :], ind[0, :], :] / 255.  # n x 3

    return colors.copy()

def ser_to_obj_single(img, ver_lst, tri, height, wfp):
    suffix = get_suffix(wfp)
    uv_coords = g_uv_coords
    n_face = tri.shape[0]
    for i, ver in enumerate(ver_lst):
        colors = get_colors(img, ver)

        n_vertex = ver.shape[1]

        wfp_new = wfp.replace(suffix, f'_{i + 1}{suffix}')

        with open(wfp_new, 'w') as f:
            for i in range(n_vertex):
                x, y, z = ver[:, i]
                f.write(
                    f'v {x:.2f} {height - y:.2f} {z:.2f} {colors[i, 2]:.2f} {colors[i, 1]:.2f} {colors[i, 0]:.2f}\n')
            for i in range(n_vertex):
                x, y = uv_coords[:, i]
                f.write(
                    f'vt {x:.2f} {height - y:.2f} {z:.2f}\n')
            for i in range(n_face):
                idx1, idx2, idx3 = tri[i]  # m x 3
                f.write(f'f {idx3 + 1} {idx2 + 1} {idx1 + 1}\n')

        print(f'Dump tp {wfp_new}')

def ser_to_obj_multiple(img, ver_lst, tri, height, wfp):
    n_obj = len(ver_lst)  # count obj

    if n_obj <= 0:
        return
    uv_coords = g_uv_coords
    print(uv_coords)
    n_vertex = ver_lst[0].shape[1]
    n_face = tri.shape[0]

    with open(wfp, 'w') as f:
        for i in range(n_obj):
            ver = ver_lst[i]
            colors = get_colors(img, ver)
            print(ver)

            for j in range(n_vertex):
                x, y, z = ver[:, j]
                f.write(
                    f'v {x:.2f} {height - y:.2f} {z:.2f} {colors[j, 2]:.2f} {colors[j, 1]:.2f} {colors[j, 0]:.2f}\n')

        for i in range(n_obj):
            ver = ver_lst[i]

            for j in range(n_vertex):
                x, y = uv_coords[j]
                f.write(
                    f'vt {x:.6f} {y:.6f}\n')

        for i in range(n_obj):
            offset = i * n_vertex
            for j in range(n_face):
                idx1, idx2, idx3 = tri[j]  # m x 3
                f.write(f'f {idx3 + 1 + offset}/{idx3 + 1 + offset} {idx2 + 1 + offset}/{idx2 + 1 + offset} {idx1 + 1 + offset}/{idx1 + 1 + offset}\n')

    print(f'Dump tp {wfp}')

ser_to_ply = ser_to_ply_multiple  # ser_to_ply_single
ser_to_obj = ser_to_obj_multiple  # ser_to_obj_multiple