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			| db6a3b7 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 | import torch
import numpy as np
from plyfile import PlyData, PlyElement
from .general_utils import inverse_sigmoid, strip_symmetric, build_scaling_rotation
class Gaussian:
    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='cuda'
        ):
        self.sh_degree = sh_degree
        self.active_sh_degree = sh_degree
        self.mininum_kernel_size = mininum_kernel_size 
        self.scaling_bias = scaling_bias
        self.opacity_bias = opacity_bias
        self.scaling_activation_type = scaling_activation
        self.device = device
        self.aabb = torch.tensor(aabb, dtype=torch.float32, device=device)
        self.setup_functions()
        self._xyz = None
        self._features_dc = None
        self._features_rest = None
        self._scaling = None
        self._rotation = None
        self._opacity = None
    def setup_functions(self):
        def build_covariance_from_scaling_rotation(scaling, scaling_modifier, rotation):
            L = build_scaling_rotation(scaling_modifier * scaling, rotation)
            actual_covariance = L @ L.transpose(1, 2)
            symm = strip_symmetric(actual_covariance)
            return symm
        
        if self.scaling_activation_type == "exp":
            self.scaling_activation = torch.exp
            self.inverse_scaling_activation = torch.log
        elif self.scaling_activation_type == "softplus":
            self.scaling_activation = torch.nn.functional.softplus
            self.inverse_scaling_activation = lambda x: x + torch.log(-torch.expm1(-x))
        self.covariance_activation = build_covariance_from_scaling_rotation
        self.opacity_activation = torch.sigmoid
        self.inverse_opacity_activation = inverse_sigmoid
        self.rotation_activation = torch.nn.functional.normalize
        
        self.scale_bias = self.inverse_scaling_activation(torch.tensor(self.scaling_bias)).cuda()
        self.rots_bias = torch.zeros((4)).cuda()
        self.rots_bias[0] = 1
        self.opacity_bias = self.inverse_opacity_activation(torch.tensor(self.opacity_bias)).cuda()
    @property
    def get_scaling(self):
        scales = self.scaling_activation(self._scaling + self.scale_bias)
        scales = torch.square(scales) + self.mininum_kernel_size ** 2
        scales = torch.sqrt(scales)
        return scales
    
    @property
    def get_rotation(self):
        return self.rotation_activation(self._rotation + self.rots_bias[None, :])
    
    @property
    def get_xyz(self):
        return self._xyz * self.aabb[None, 3:] + self.aabb[None, :3]
    
    @property
    def get_features(self):
        return torch.cat((self._features_dc, self._features_rest), dim=2) if self._features_rest is not None else self._features_dc
    
    @property
    def get_opacity(self):
        return self.opacity_activation(self._opacity + self.opacity_bias)
    
    def get_covariance(self, scaling_modifier = 1):
        return self.covariance_activation(self.get_scaling, scaling_modifier, self._rotation + self.rots_bias[None, :])
    
    def from_scaling(self, scales):
        scales = torch.sqrt(torch.square(scales) - self.mininum_kernel_size ** 2)
        self._scaling = self.inverse_scaling_activation(scales) - self.scale_bias
        
    def from_rotation(self, rots):
        self._rotation = rots - self.rots_bias[None, :]
    
    def from_xyz(self, xyz):
        self._xyz = (xyz - self.aabb[None, :3]) / self.aabb[None, 3:]
        
    def from_features(self, features):
        self._features_dc = features
        
    def from_opacity(self, opacities):
        self._opacity = self.inverse_opacity_activation(opacities) - self.opacity_bias
    def construct_list_of_attributes(self):
        l = ['x', 'y', 'z', 'nx', 'ny', 'nz']
        # All channels except the 3 DC
        for i in range(self._features_dc.shape[1]*self._features_dc.shape[2]):
            l.append('f_dc_{}'.format(i))
        l.append('opacity')
        for i in range(self._scaling.shape[1]):
            l.append('scale_{}'.format(i))
        for i in range(self._rotation.shape[1]):
            l.append('rot_{}'.format(i))
        return l
    def save_ply(self, path):
        xyz = self.get_xyz.detach().cpu().numpy()
        normals = np.zeros_like(xyz)
        f_dc = self._features_dc.detach().transpose(1, 2).flatten(start_dim=1).contiguous().cpu().numpy()
        opacities = inverse_sigmoid(self.get_opacity).detach().cpu().numpy()
        scale = torch.log(self.get_scaling).detach().cpu().numpy()
        rotation = (self._rotation + self.rots_bias[None, :]).detach().cpu().numpy()
        dtype_full = [(attribute, 'f4') for attribute in self.construct_list_of_attributes()]
        elements = np.empty(xyz.shape[0], dtype=dtype_full)
        attributes = np.concatenate((xyz, normals, f_dc, opacities, scale, rotation), axis=1)
        elements[:] = list(map(tuple, attributes))
        el = PlyElement.describe(elements, 'vertex')
        PlyData([el]).write(path)
    def load_ply(self, path):
        plydata = PlyData.read(path)
        xyz = np.stack((np.asarray(plydata.elements[0]["x"]),
                        np.asarray(plydata.elements[0]["y"]),
                        np.asarray(plydata.elements[0]["z"])),  axis=1)
        opacities = np.asarray(plydata.elements[0]["opacity"])[..., np.newaxis]
        features_dc = np.zeros((xyz.shape[0], 3, 1))
        features_dc[:, 0, 0] = np.asarray(plydata.elements[0]["f_dc_0"])
        features_dc[:, 1, 0] = np.asarray(plydata.elements[0]["f_dc_1"])
        features_dc[:, 2, 0] = np.asarray(plydata.elements[0]["f_dc_2"])
        if self.sh_degree > 0:
            extra_f_names = [p.name for p in plydata.elements[0].properties if p.name.startswith("f_rest_")]
            extra_f_names = sorted(extra_f_names, key = lambda x: int(x.split('_')[-1]))
            assert len(extra_f_names)==3*(self.sh_degree + 1) ** 2 - 3
            features_extra = np.zeros((xyz.shape[0], len(extra_f_names)))
            for idx, attr_name in enumerate(extra_f_names):
                features_extra[:, idx] = np.asarray(plydata.elements[0][attr_name])
            # Reshape (P,F*SH_coeffs) to (P, F, SH_coeffs except DC)
            features_extra = features_extra.reshape((features_extra.shape[0], 3, (self.max_sh_degree + 1) ** 2 - 1))
        scale_names = [p.name for p in plydata.elements[0].properties if p.name.startswith("scale_")]
        scale_names = sorted(scale_names, key = lambda x: int(x.split('_')[-1]))
        scales = np.zeros((xyz.shape[0], len(scale_names)))
        for idx, attr_name in enumerate(scale_names):
            scales[:, idx] = np.asarray(plydata.elements[0][attr_name])
        rot_names = [p.name for p in plydata.elements[0].properties if p.name.startswith("rot")]
        rot_names = sorted(rot_names, key = lambda x: int(x.split('_')[-1]))
        rots = np.zeros((xyz.shape[0], len(rot_names)))
        for idx, attr_name in enumerate(rot_names):
            rots[:, idx] = np.asarray(plydata.elements[0][attr_name])
            
        # convert to actual gaussian attributes
        xyz = torch.tensor(xyz, dtype=torch.float, device=self.device)
        features_dc = torch.tensor(features_dc, dtype=torch.float, device=self.device).transpose(1, 2).contiguous()
        if self.sh_degree > 0:
            features_extra = torch.tensor(features_extra, dtype=torch.float, device=self.device).transpose(1, 2).contiguous()
        opacities = torch.sigmoid(torch.tensor(opacities, dtype=torch.float, device=self.device))
        scales = torch.exp(torch.tensor(scales, dtype=torch.float, device=self.device))
        rots = torch.tensor(rots, dtype=torch.float, device=self.device)
        
        # convert to _hidden attributes
        self._xyz = (xyz - self.aabb[None, :3]) / self.aabb[None, 3:]
        self._features_dc = features_dc
        if self.sh_degree > 0:
            self._features_rest = features_extra
        else:
            self._features_rest = None
        self._opacity = self.inverse_opacity_activation(opacities) - self.opacity_bias
        self._scaling = self.inverse_scaling_activation(torch.sqrt(torch.square(scales) - self.mininum_kernel_size ** 2)) - self.scale_bias
        self._rotation = rots - self.rots_bias[None, :]
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