Kiss3DGen / shader.py
JiantaoLin
new
235efa3
import torch
from pytorch3d.renderer.mesh.shader import ShaderBase
from pytorch3d.renderer import (
SoftPhongShader,
)
from pytorch3d.renderer import BlendParams
class MultiOutputShader(ShaderBase):
def __init__(self, device, cameras, lights, materials, ccm_scale=1.0, choices=None):
super().__init__()
self.device = device
self.cameras = cameras
self.lights = lights
self.materials = materials
self.ccm_scale = ccm_scale
if choices is None:
self.choices = ["rgb", "mask", "depth", "normal", "albedo", "ccm"]
else:
self.choices = choices
blend_params = BlendParams(sigma=1e-4, gamma=1e-4)
self.phong_shader = SoftPhongShader(
device=self.device,
cameras=self.cameras,
lights=self.lights,
materials=self.materials,
blend_params=blend_params
)
def forward(self, fragments, meshes, **kwargs):
batch_size, H, W, _ = fragments.zbuf.shape
output = {}
if "rgb" in self.choices:
rgb_images = self.phong_shader(fragments, meshes, **kwargs)
rgb = rgb_images[..., :3]
output["rgb"] = rgb
if "mask" in self.choices:
alpha = rgb_images[..., 3:4]
mask = (alpha > 0).float()
output["mask"] = mask
if "albedo" in self.choices:
albedo = meshes.sample_textures(fragments)
output["albedo"] = albedo[..., 0, :]
if "depth" in self.choices:
depth = fragments.zbuf
output["depth"] = depth
if "normal" in self.choices:
pix_to_face = fragments.pix_to_face[..., 0]
bary_coords = fragments.bary_coords[..., 0, :]
valid_mask = pix_to_face >= 0
face_indices = pix_to_face[valid_mask]
faces_packed = meshes.faces_packed()
normals_packed = meshes.verts_normals_packed()
face_vertex_normals = normals_packed[faces_packed[face_indices]]
bary = bary_coords.view(-1, 3)[valid_mask.view(-1)]
interpolated_normals = (
bary[..., 0:1] * face_vertex_normals[:, 0, :] +
bary[..., 1:2] * face_vertex_normals[:, 1, :] +
bary[..., 2:3] * face_vertex_normals[:, 2, :]
)
interpolated_normals = interpolated_normals / interpolated_normals.norm(dim=-1, keepdim=True)
normal = torch.zeros(batch_size, H, W, 3, device=self.device)
normal[valid_mask] = interpolated_normals
output["normal"] = normal
if "ccm" in self.choices:
face_vertices = meshes.verts_packed()[meshes.faces_packed()]
faces_at_pixels = face_vertices[fragments.pix_to_face]
ccm = torch.sum(fragments.bary_coords.unsqueeze(-1) * faces_at_pixels, dim=-2)
ccm = (ccm[..., 0, :] * self.ccm_scale + 1) / 2
output["ccm"] = ccm
return output