dreamgaussian / mesh_renderer.py
jiawei011's picture
init
12b7f59
raw history blame
No virus
5.67 kB
import os
import math
import cv2
import trimesh
import numpy as np
import torch
import torch.nn as nn
import torch.nn.functional as F
import nvdiffrast.torch as dr
from mesh import Mesh, safe_normalize
def scale_img_nhwc(x, size, mag='bilinear', min='bilinear'):
assert (x.shape[1] >= size[0] and x.shape[2] >= size[1]) or (x.shape[1] < size[0] and x.shape[2] < size[1]), "Trying to magnify image in one dimension and minify in the other"
y = x.permute(0, 3, 1, 2) # NHWC -> NCHW
if x.shape[1] > size[0] and x.shape[2] > size[1]: # Minification, previous size was bigger
y = torch.nn.functional.interpolate(y, size, mode=min)
else: # Magnification
if mag == 'bilinear' or mag == 'bicubic':
y = torch.nn.functional.interpolate(y, size, mode=mag, align_corners=True)
else:
y = torch.nn.functional.interpolate(y, size, mode=mag)
return y.permute(0, 2, 3, 1).contiguous() # NCHW -> NHWC
def scale_img_hwc(x, size, mag='bilinear', min='bilinear'):
return scale_img_nhwc(x[None, ...], size, mag, min)[0]
def scale_img_nhw(x, size, mag='bilinear', min='bilinear'):
return scale_img_nhwc(x[..., None], size, mag, min)[..., 0]
def scale_img_hw(x, size, mag='bilinear', min='bilinear'):
return scale_img_nhwc(x[None, ..., None], size, mag, min)[0, ..., 0]
def trunc_rev_sigmoid(x, eps=1e-6):
x = x.clamp(eps, 1 - eps)
return torch.log(x / (1 - x))
def make_divisible(x, m=8):
return int(math.ceil(x / m) * m)
class Renderer(nn.Module):
def __init__(self, opt):
super().__init__()
self.opt = opt
self.mesh = Mesh.load(self.opt.mesh, resize=False)
if not self.opt.force_cuda_rast and (not self.opt.gui or os.name == 'nt'):
self.glctx = dr.RasterizeGLContext()
else:
self.glctx = dr.RasterizeCudaContext()
# extract trainable parameters
self.v_offsets = nn.Parameter(torch.zeros_like(self.mesh.v))
self.raw_albedo = nn.Parameter(trunc_rev_sigmoid(self.mesh.albedo))
def get_params(self):
params = [
{'params': self.raw_albedo, 'lr': self.opt.texture_lr},
]
if self.opt.train_geo:
params.append({'params': self.v_offsets, 'lr': self.opt.geom_lr})
return params
@torch.no_grad()
def export_mesh(self, save_path):
self.mesh.v = (self.mesh.v + self.v_offsets).detach()
self.mesh.albedo = torch.sigmoid(self.raw_albedo.detach())
self.mesh.write(save_path)
def render(self, pose, proj, h0, w0, ssaa=1, bg_color=1, texture_filter='linear-mipmap-linear'):
# do super-sampling
if ssaa != 1:
h = make_divisible(h0 * ssaa, 8)
w = make_divisible(w0 * ssaa, 8)
else:
h, w = h0, w0
results = {}
# get v
if self.opt.train_geo:
v = self.mesh.v + self.v_offsets # [N, 3]
else:
v = self.mesh.v
pose = torch.from_numpy(pose.astype(np.float32)).to(v.device)
proj = torch.from_numpy(proj.astype(np.float32)).to(v.device)
# get v_clip and render rgb
v_cam = torch.matmul(F.pad(v, pad=(0, 1), mode='constant', value=1.0), torch.inverse(pose).T).float().unsqueeze(0)
v_clip = v_cam @ proj.T
rast, rast_db = dr.rasterize(self.glctx, v_clip, self.mesh.f, (h, w))
alpha = (rast[0, ..., 3:] > 0).float()
depth, _ = dr.interpolate(-v_cam[..., [2]], rast, self.mesh.f) # [1, H, W, 1]
depth = depth.squeeze(0) # [H, W, 1]
texc, texc_db = dr.interpolate(self.mesh.vt.unsqueeze(0).contiguous(), rast, self.mesh.ft, rast_db=rast_db, diff_attrs='all')
albedo = dr.texture(self.raw_albedo.unsqueeze(0), texc, uv_da=texc_db, filter_mode=texture_filter) # [1, H, W, 3]
albedo = torch.sigmoid(albedo)
# get vn and render normal
if self.opt.train_geo:
i0, i1, i2 = self.mesh.f[:, 0].long(), self.mesh.f[:, 1].long(), self.mesh.f[:, 2].long()
v0, v1, v2 = v[i0, :], v[i1, :], v[i2, :]
face_normals = torch.cross(v1 - v0, v2 - v0)
face_normals = safe_normalize(face_normals)
vn = torch.zeros_like(v)
vn.scatter_add_(0, i0[:, None].repeat(1,3), face_normals)
vn.scatter_add_(0, i1[:, None].repeat(1,3), face_normals)
vn.scatter_add_(0, i2[:, None].repeat(1,3), face_normals)
vn = torch.where(torch.sum(vn * vn, -1, keepdim=True) > 1e-20, vn, torch.tensor([0.0, 0.0, 1.0], dtype=torch.float32, device=vn.device))
else:
vn = self.mesh.vn
normal, _ = dr.interpolate(vn.unsqueeze(0).contiguous(), rast, self.mesh.fn)
normal = safe_normalize(normal[0])
# rotated normal (where [0, 0, 1] always faces camera)
rot_normal = normal @ pose[:3, :3]
viewcos = rot_normal[..., [2]]
# antialias
albedo = dr.antialias(albedo, rast, v_clip, self.mesh.f).squeeze(0) # [H, W, 3]
albedo = alpha * albedo + (1 - alpha) * bg_color
# ssaa
if ssaa != 1:
albedo = scale_img_hwc(albedo, (h0, w0))
alpha = scale_img_hwc(alpha, (h0, w0))
depth = scale_img_hwc(depth, (h0, w0))
normal = scale_img_hwc(normal, (h0, w0))
viewcos = scale_img_hwc(viewcos, (h0, w0))
results['image'] = albedo.clamp(0, 1)
results['alpha'] = alpha
results['depth'] = depth
results['normal'] = (normal + 1) / 2
results['viewcos'] = viewcos
return results