ComfyUI/comfy/ldm/triposplat/gaussian.py
2026-06-01 07:01:50 -07:00

200 lines
7.9 KiB
Python

# TripoSplat 3D gaussian container. Operates on already-decoded
# tensors and exposes them as render-ready tensors (render_tensors) for the generic SPLAT type.
import torch
import torch.nn.functional as F
import comfy.model_management
class GaussianModel:
def __init__(self, aabb: list, sh_degree: int = 0, mininum_kernel_size: float = 0.0,
scaling_bias: float = 0.01, opacity_bias: float = 0.1,
scaling_activation: str = "exp", device=None):
self.sh_degree = sh_degree
self.mininum_kernel_size = mininum_kernel_size
self.scaling_bias = scaling_bias
self.opacity_bias = opacity_bias
self.device = device
self.aabb = torch.tensor(aabb, dtype=torch.float32, device=device)
if scaling_activation == "exp":
self._scaling_activation = torch.exp
self._inverse_scaling_activation = torch.log
elif scaling_activation == "softplus":
self._scaling_activation = F.softplus
self._inverse_scaling_activation = lambda x: x + torch.log(-torch.expm1(-x))
self._opacity_activation = torch.sigmoid
self._inverse_opacity_activation = lambda x: torch.log(x / (1 - x))
self.scale_bias = self._inverse_scaling_activation(torch.tensor(self.scaling_bias)).to(self.device)
self.rots_bias = torch.zeros(4, device=self.device)
self.rots_bias[0] = 1
self.opacity_bias_val = self._inverse_opacity_activation(torch.tensor(self.opacity_bias)).to(self.device)
self._storage = {}
def _get_store(self, name):
return self._storage.get(name)
def _set_store(self, name, value):
self._storage[name] = value
@property
def _xyz(self):
return self._get_store("_xyz")
@_xyz.setter
def _xyz(self, value):
if value is None:
self._set_store("_xyz", None)
self._set_store("xyz", None)
return
self._set_store("_xyz", value)
self._set_store("xyz", value * self.aabb[None, 3:] + self.aabb[None, :3])
@property
def get_xyz(self):
return self._get_store("xyz")
@property
def _features_dc(self):
return self._get_store("_features_dc")
@_features_dc.setter
def _features_dc(self, value):
self._set_store("_features_dc", value)
@property
def _opacity(self):
return self._get_store("_opacity")
@_opacity.setter
def _opacity(self, value):
if value is None:
self._set_store("_opacity", None)
self._set_store("opacity", None)
return
self._set_store("_opacity", value)
self._set_store("opacity", self._opacity_activation(value + self.opacity_bias_val))
@property
def get_opacity(self):
return self._get_store("opacity")
@property
def _scaling(self):
return self._get_store("_scaling")
@_scaling.setter
def _scaling(self, value):
if value is None:
self._set_store("_scaling", None)
self._set_store("scaling", None)
return
self._set_store("_scaling", value)
s = self._scaling_activation(value + self.scale_bias)
s = torch.square(s) + self.mininum_kernel_size ** 2
self._set_store("scaling", torch.sqrt(s))
@property
def get_scaling(self):
return self._get_store("scaling")
@property
def _rotation(self):
return self._get_store("_rotation")
@_rotation.setter
def _rotation(self, value):
self._set_store("_rotation", value)
_DEFAULT_TRANSFORM = [[1, 0, 0], [0, 0, -1], [0, 1, 0]]
def render_tensors(self):
# Render-ready (activated, world-space) tensors for the generic SPLAT type. The axis transform
# (a 3x3 rotation, object frame -> viewer Y-up) is baked into positions and rotations.
# Returns float tensors on the intermediate device: positions (N,3), scales (N,3) linear,
# rotations (N,4) wxyz, opacities (N,1) in [0,1], sh (N,K,3) coefficients.
xyz = self.get_xyz.float()
scaling = self.get_scaling.float()
opacity = self.get_opacity.float()
rotation = (self._rotation + self.rots_bias[None, :]).float()
sh = self._features_dc.float() # (N, K, 3)
T = torch.as_tensor(self._DEFAULT_TRANSFORM, dtype=torch.float32, device=xyz.device)
xyz = xyz @ T.T
rotation = _matrix_to_quat(torch.matmul(T, _quat_to_matrix(rotation)))
rotation = rotation / torch.linalg.norm(rotation, dim=-1, keepdim=True)
out_device = comfy.model_management.intermediate_device()
return (
xyz.to(out_device).contiguous(), scaling.to(out_device).contiguous(),
rotation.to(out_device).contiguous(), opacity.to(out_device).contiguous(),
sh.to(out_device).contiguous(),
)
def _quat_to_matrix(q):
q = q / torch.linalg.norm(q, dim=-1, keepdim=True)
w, x, y, z = q[:, 0], q[:, 1], q[:, 2], q[:, 3]
R = torch.stack([
1 - 2*(y*y + z*z), 2*(x*y - w*z), 2*(x*z + w*y),
2*(x*y + w*z), 1 - 2*(x*x + z*z), 2*(y*z - w*x),
2*(x*z - w*y), 2*(y*z + w*x), 1 - 2*(x*x + y*y),
], dim=-1).reshape(-1, 3, 3)
return R
def _matrix_to_quat(R):
trace = R[:, 0, 0] + R[:, 1, 1] + R[:, 2, 2]
q = torch.zeros((R.shape[0], 4), dtype=R.dtype, device=R.device)
s = torch.sqrt(torch.clamp(trace + 1, min=0)) * 2
q[:, 0] = 0.25 * s
denom = torch.where(s != 0, s, torch.ones_like(s))
q[:, 1] = (R[:, 2, 1] - R[:, 1, 2]) / denom
q[:, 2] = (R[:, 0, 2] - R[:, 2, 0]) / denom
q[:, 3] = (R[:, 1, 0] - R[:, 0, 1]) / denom
m01 = (R[:, 0, 0] >= R[:, 1, 1]) & (R[:, 0, 0] >= R[:, 2, 2]) & (s == 0)
s1 = torch.sqrt(torch.clamp(1 + R[:, 0, 0] - R[:, 1, 1] - R[:, 2, 2], min=0)) * 2
q[m01, 0] = (R[m01, 2, 1] - R[m01, 1, 2]) / s1[m01]
q[m01, 1] = 0.25 * s1[m01]
q[m01, 2] = (R[m01, 0, 1] + R[m01, 1, 0]) / s1[m01]
q[m01, 3] = (R[m01, 0, 2] + R[m01, 2, 0]) / s1[m01]
m11 = (R[:, 1, 1] > R[:, 0, 0]) & (R[:, 1, 1] >= R[:, 2, 2]) & (s == 0)
s2 = torch.sqrt(torch.clamp(1 + R[:, 1, 1] - R[:, 0, 0] - R[:, 2, 2], min=0)) * 2
q[m11, 0] = (R[m11, 0, 2] - R[m11, 2, 0]) / s2[m11]
q[m11, 1] = (R[m11, 0, 1] + R[m11, 1, 0]) / s2[m11]
q[m11, 2] = 0.25 * s2[m11]
q[m11, 3] = (R[m11, 1, 2] + R[m11, 2, 1]) / s2[m11]
m21 = (R[:, 2, 2] > R[:, 0, 0]) & (R[:, 2, 2] > R[:, 1, 1]) & (s == 0)
s3 = torch.sqrt(torch.clamp(1 + R[:, 2, 2] - R[:, 0, 0] - R[:, 1, 1], min=0)) * 2
q[m21, 0] = (R[m21, 1, 0] - R[m21, 0, 1]) / s3[m21]
q[m21, 1] = (R[m21, 0, 2] + R[m21, 2, 0]) / s3[m21]
q[m21, 2] = (R[m21, 1, 2] + R[m21, 2, 1]) / s3[m21]
q[m21, 3] = 0.25 * s3[m21]
return q / torch.linalg.norm(q, dim=-1, keepdim=True)
def build_gaussian_models(decoder, points_pred: dict, pred: dict):
# Assemble GaussianModels from the elastic decoder layout. decoder is the ElasticGaussianFixedlenDecoder
# (carries layout / rep_config / _get_offset)
x = points_pred
offset = decoder._get_offset(pred['features'])
h = pred["features"]
ret = []
for i in range(h.shape[0]):
g = GaussianModel(
sh_degree=0,
aabb=[-0.5, -0.5, -0.5, 1.0, 1.0, 1.0],
mininum_kernel_size=decoder.rep_config['filter_kernel_size_3d'],
scaling_bias=decoder.rep_config['scaling_bias'],
opacity_bias=decoder.rep_config['opacity_bias'],
scaling_activation=decoder.rep_config['scaling_activation'],
device=h.device,
)
_x = x["points"][i, :, None, :]
for k, v in decoder.layout.items():
if k == '_xyz':
setattr(g, k, (offset[i] + _x).flatten(0, 1))
elif k in ('_xyz_center', '_offset_scale'):
continue
else:
feats = h[i][:, v['range'][0]:v['range'][1]].reshape(-1, *v['shape']).flatten(0, 1)
setattr(g, k, feats * decoder.rep_config['lr'][k])
ret.append(g)
return ret