TRELLIS-WORKS / trellis /renderers /mesh_renderer.py
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# Copyright (c) 2023, NVIDIA CORPORATION & AFFILIATES. All rights reserved.
#
# NVIDIA CORPORATION & AFFILIATES 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 & AFFILIATES is strictly prohibited.
import torch
try:
import kaolin as kal
import nvdiffrast.torch as dr
except :
print("Kaolin and nvdiffrast are not installed. Please install them to use the mesh renderer.")
from easydict import EasyDict as edict
from ..representations.mesh import MeshExtractResult
import torch.nn.functional as F
def intrinsics_to_projection(
intrinsics: torch.Tensor,
near: float,
far: float,
) -> torch.Tensor:
"""
OpenCV intrinsics to OpenGL perspective matrix
Args:
intrinsics (torch.Tensor): [3, 3] OpenCV intrinsics matrix
near (float): near plane to clip
far (float): far plane to clip
Returns:
(torch.Tensor): [4, 4] OpenGL perspective matrix
"""
fx, fy = intrinsics[0, 0], intrinsics[1, 1]
cx, cy = intrinsics[0, 2], intrinsics[1, 2]
ret = torch.zeros((4, 4), dtype=intrinsics.dtype, device=intrinsics.device)
ret[0, 0] = 2 * fx
ret[1, 1] = 2 * fy
ret[0, 2] = 2 * cx - 1
ret[1, 2] = - 2 * cy + 1
ret[2, 2] = far / (far - near)
ret[2, 3] = near * far / (near - far)
ret[3, 2] = 1.
return ret
class MeshRenderer:
"""
Renderer for the Mesh representation.
Args:
rendering_options (dict): Rendering options.
glctx (nvdiffrast.torch.RasterizeGLContext): RasterizeGLContext object for CUDA/OpenGL interop.
"""
def __init__(self, rendering_options={}, device='cuda'):
self.rendering_options = edict({
"resolution": None,
"near": None,
"far": None,
"ssaa": 1
})
self.rendering_options.update(rendering_options)
self.glctx = dr.RasterizeCudaContext(device=device)
self.device=device
def render(
self,
mesh : MeshExtractResult,
extrinsics: torch.Tensor,
intrinsics: torch.Tensor,
return_types = ["mask", "normal", "depth"]
) -> edict:
"""
Render the mesh.
Args:
mesh : meshmodel
extrinsics (torch.Tensor): (4, 4) camera extrinsics
intrinsics (torch.Tensor): (3, 3) camera intrinsics
return_types (list): list of return types, can be "mask", "depth", "normal_map", "normal", "color"
Returns:
edict based on return_types containing:
color (torch.Tensor): [3, H, W] rendered color image
depth (torch.Tensor): [H, W] rendered depth image
normal (torch.Tensor): [3, H, W] rendered normal image
normal_map (torch.Tensor): [3, H, W] rendered normal map image
mask (torch.Tensor): [H, W] rendered mask image
"""
resolution = self.rendering_options["resolution"]
near = self.rendering_options["near"]
far = self.rendering_options["far"]
ssaa = self.rendering_options["ssaa"]
if mesh.vertices.shape[0] == 0 or mesh.faces.shape[0] == 0:
default_img = torch.zeros((1, resolution, resolution, 3), dtype=torch.float32, device=self.device)
ret_dict = {k : default_img if k in ['normal', 'normal_map', 'color'] else default_img[..., :1] for k in return_types}
return ret_dict
perspective = intrinsics_to_projection(intrinsics, near, far)
RT = extrinsics.unsqueeze(0)
full_proj = (perspective @ extrinsics).unsqueeze(0)
vertices = mesh.vertices.unsqueeze(0)
vertices_homo = torch.cat([vertices, torch.ones_like(vertices[..., :1])], dim=-1)
vertices_camera = torch.bmm(vertices_homo, RT.transpose(-1, -2))
vertices_clip = torch.bmm(vertices_homo, full_proj.transpose(-1, -2))
faces_int = mesh.faces.int()
rast, _ = dr.rasterize(
self.glctx, vertices_clip, faces_int, (resolution * ssaa, resolution * ssaa))
out_dict = edict()
for type in return_types:
img = None
if type == "mask" :
img = dr.antialias((rast[..., -1:] > 0).float(), rast, vertices_clip, faces_int)
elif type == "depth":
img = dr.interpolate(vertices_camera[..., 2:3].contiguous(), rast, faces_int)[0]
img = dr.antialias(img, rast, vertices_clip, faces_int)
elif type == "normal" :
img = dr.interpolate(
mesh.face_normal.reshape(1, -1, 3), rast,
torch.arange(mesh.faces.shape[0] * 3, device=self.device, dtype=torch.int).reshape(-1, 3)
)[0]
img = dr.antialias(img, rast, vertices_clip, faces_int)
# normalize norm pictures
img = (img + 1) / 2
elif type == "normal_map" :
img = dr.interpolate(mesh.vertex_attrs[:, 3:].contiguous(), rast, faces_int)[0]
img = dr.antialias(img, rast, vertices_clip, faces_int)
elif type == "color" :
img = dr.interpolate(mesh.vertex_attrs[:, :3].contiguous(), rast, faces_int)[0]
img = dr.antialias(img, rast, vertices_clip, faces_int)
if ssaa > 1:
img = F.interpolate(img.permute(0, 3, 1, 2), (resolution, resolution), mode='bilinear', align_corners=False, antialias=True)
img = img.squeeze()
else:
img = img.permute(0, 3, 1, 2).squeeze()
out_dict[type] = img
return out_dict