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Running
on
Zero
from typing import * | |
import torch | |
import torch.nn as nn | |
import torch.nn.functional as F | |
from ...modules import sparse as sp | |
from ...utils.random_utils import hammersley_sequence | |
from .base import SparseTransformerBase | |
from ...representations import Gaussian | |
class SLatGaussianDecoder(SparseTransformerBase): | |
def __init__( | |
self, | |
resolution: int, | |
model_channels: int, | |
latent_channels: int, | |
num_blocks: int, | |
num_heads: Optional[int] = None, | |
num_head_channels: Optional[int] = 64, | |
mlp_ratio: float = 4, | |
attn_mode: Literal["full", "shift_window", "shift_sequence", "shift_order", "swin"] = "swin", | |
window_size: int = 8, | |
pe_mode: Literal["ape", "rope"] = "ape", | |
use_fp16: bool = False, | |
use_checkpoint: bool = False, | |
qk_rms_norm: bool = False, | |
representation_config: dict = None, | |
): | |
super().__init__( | |
in_channels=latent_channels, | |
model_channels=model_channels, | |
num_blocks=num_blocks, | |
num_heads=num_heads, | |
num_head_channels=num_head_channels, | |
mlp_ratio=mlp_ratio, | |
attn_mode=attn_mode, | |
window_size=window_size, | |
pe_mode=pe_mode, | |
use_fp16=use_fp16, | |
use_checkpoint=use_checkpoint, | |
qk_rms_norm=qk_rms_norm, | |
) | |
self.resolution = resolution | |
self.rep_config = representation_config | |
self._calc_layout() | |
self.out_layer = sp.SparseLinear(model_channels, self.out_channels) | |
self._build_perturbation() | |
self.initialize_weights() | |
if use_fp16: | |
self.convert_to_fp16() | |
def initialize_weights(self) -> None: | |
super().initialize_weights() | |
# Zero-out output layers: | |
nn.init.constant_(self.out_layer.weight, 0) | |
nn.init.constant_(self.out_layer.bias, 0) | |
def _build_perturbation(self) -> None: | |
perturbation = [hammersley_sequence(3, i, self.rep_config['num_gaussians']) for i in range(self.rep_config['num_gaussians'])] | |
perturbation = torch.tensor(perturbation).float() * 2 - 1 | |
perturbation = perturbation / self.rep_config['voxel_size'] | |
perturbation = torch.atanh(perturbation).to(self.device) | |
self.register_buffer('offset_perturbation', perturbation) | |
def _calc_layout(self) -> None: | |
self.layout = { | |
'_xyz' : {'shape': (self.rep_config['num_gaussians'], 3), 'size': self.rep_config['num_gaussians'] * 3}, | |
'_features_dc' : {'shape': (self.rep_config['num_gaussians'], 1, 3), 'size': self.rep_config['num_gaussians'] * 3}, | |
'_scaling' : {'shape': (self.rep_config['num_gaussians'], 3), 'size': self.rep_config['num_gaussians'] * 3}, | |
'_rotation' : {'shape': (self.rep_config['num_gaussians'], 4), 'size': self.rep_config['num_gaussians'] * 4}, | |
'_opacity' : {'shape': (self.rep_config['num_gaussians'], 1), 'size': self.rep_config['num_gaussians']}, | |
} | |
start = 0 | |
for k, v in self.layout.items(): | |
v['range'] = (start, start + v['size']) | |
start += v['size'] | |
self.out_channels = start | |
def to_representation(self, x: sp.SparseTensor) -> List[Gaussian]: | |
""" | |
Convert a batch of network outputs to 3D representations. | |
Args: | |
x: The [N x * x C] sparse tensor output by the network. | |
Returns: | |
list of representations | |
""" | |
ret = [] | |
for i in range(x.shape[0]): | |
representation = Gaussian( | |
sh_degree=0, | |
aabb=[-0.5, -0.5, -0.5, 1.0, 1.0, 1.0], | |
mininum_kernel_size = self.rep_config['3d_filter_kernel_size'], | |
scaling_bias = self.rep_config['scaling_bias'], | |
opacity_bias = self.rep_config['opacity_bias'], | |
scaling_activation = self.rep_config['scaling_activation'] | |
) | |
xyz = (x.coords[x.layout[i]][:, 1:].float() + 0.5) / self.resolution | |
for k, v in self.layout.items(): | |
if k == '_xyz': | |
offset = x.feats[x.layout[i]][:, v['range'][0]:v['range'][1]].reshape(-1, *v['shape']) | |
offset = offset * self.rep_config['lr'][k] | |
if self.rep_config['perturb_offset']: | |
offset = offset + self.offset_perturbation | |
offset = torch.tanh(offset) / self.resolution * 0.5 * self.rep_config['voxel_size'] | |
_xyz = xyz.unsqueeze(1) + offset | |
setattr(representation, k, _xyz.flatten(0, 1)) | |
else: | |
feats = x.feats[x.layout[i]][:, v['range'][0]:v['range'][1]].reshape(-1, *v['shape']).flatten(0, 1) | |
feats = feats * self.rep_config['lr'][k] | |
setattr(representation, k, feats) | |
ret.append(representation) | |
return ret | |
def forward(self, x: sp.SparseTensor) -> List[Gaussian]: | |
h = super().forward(x) | |
h = h.type(x.dtype) | |
h = h.replace(F.layer_norm(h.feats, h.feats.shape[-1:])) | |
h = self.out_layer(h) | |
return self.to_representation(h) | |