diff options
Diffstat (limited to 'io_scene_gltf2/io/imp/gltf2_io_binary.py')
| -rwxr-xr-x | io_scene_gltf2/io/imp/gltf2_io_binary.py | 136 |
1 files changed, 84 insertions, 52 deletions
diff --git a/io_scene_gltf2/io/imp/gltf2_io_binary.py b/io_scene_gltf2/io/imp/gltf2_io_binary.py index 7cfcbc40..728cf0f0 100755 --- a/io_scene_gltf2/io/imp/gltf2_io_binary.py +++ b/io_scene_gltf2/io/imp/gltf2_io_binary.py @@ -13,6 +13,7 @@ # limitations under the License. import struct +import numpy as np from ..com.gltf2_io import Accessor @@ -22,8 +23,8 @@ class BinaryData(): def __new__(cls, *args, **kwargs): raise RuntimeError("%s should not be instantiated" % cls) -# Note that this function is not used in Blender importer, but is kept in -# Source code to be used in any pipeline that want to manage gltf/glb file in python + # Note that this function is not used in Blender importer, but is kept in + # Source code to be used in any pipeline that want to manage gltf/glb file in python @staticmethod def get_binary_from_accessor(gltf, accessor_idx): """Get binary from accessor.""" @@ -63,8 +64,7 @@ class BinaryData(): if accessor_idx in gltf.accessor_cache: return gltf.accessor_cache[accessor_idx] - accessor = gltf.data.accessors[accessor_idx] - data = BinaryData.get_data_from_accessor_obj(gltf, accessor) + data = BinaryData.decode_accessor(gltf, accessor_idx).tolist() if cache: gltf.accessor_cache[accessor_idx] = data @@ -72,7 +72,36 @@ class BinaryData(): return data @staticmethod - def get_data_from_accessor_obj(gltf, accessor): + def decode_accessor(gltf, accessor_idx, cache=False): + """Decodes accessor to 2D numpy array (count x num_components).""" + if accessor_idx in gltf.decode_accessor_cache: + return gltf.accessor_cache[accessor_idx] + + accessor = gltf.data.accessors[accessor_idx] + array = BinaryData.decode_accessor_obj(gltf, accessor) + + if cache: + gltf.accessor_cache[accessor_idx] = array + # Prevent accidentally modifying cached arrays + array.flags.writeable = False + + return array + + @staticmethod + def decode_accessor_obj(gltf, accessor): + # MAT2/3 have special alignment requirements that aren't handled. But it + # doesn't matter because nothing uses them. + assert accessor.type not in ['MAT2', 'MAT3'] + + dtype = { + 5120: np.int8, + 5121: np.uint8, + 5122: np.int16, + 5123: np.uint16, + 5125: np.uint32, + 5126: np.float32, + }[accessor.component_type] + if accessor.buffer_view is not None: bufferView = gltf.data.buffer_views[accessor.buffer_view] buffer_data = BinaryData.get_buffer_view(gltf, accessor.buffer_view) @@ -80,40 +109,45 @@ class BinaryData(): accessor_offset = accessor.byte_offset or 0 buffer_data = buffer_data[accessor_offset:] - fmt_char = gltf.fmt_char_dict[accessor.component_type] component_nb = gltf.component_nb_dict[accessor.type] - fmt = '<' + (fmt_char * component_nb) - default_stride = struct.calcsize(fmt) - - # Special layouts for certain formats; see the section about - # data alignment in the glTF 2.0 spec. - component_size = struct.calcsize('<' + fmt_char) - if accessor.type == 'MAT2' and component_size == 1: - fmt = '<FFxxFF'.replace('F', fmt_char) - default_stride = 8 - elif accessor.type == 'MAT3' and component_size == 1: - fmt = '<FFFxFFFxFFF'.replace('F', fmt_char) - default_stride = 12 - elif accessor.type == 'MAT3' and component_size == 2: - fmt = '<FFFxxFFFxxFFF'.replace('F', fmt_char) - default_stride = 24 + bytes_per_elem = dtype(1).nbytes + default_stride = bytes_per_elem * component_nb stride = bufferView.byte_stride or default_stride - # Decode - unpack_from = struct.Struct(fmt).unpack_from - data = [ - unpack_from(buffer_data, offset) - for offset in range(0, accessor.count*stride, stride) - ] + if stride == default_stride: + array = np.frombuffer( + buffer_data, + dtype=np.dtype(dtype).newbyteorder('<'), + count=accessor.count * component_nb, + ) + array = array.reshape(accessor.count, component_nb) + + else: + # The data looks like + # XXXppXXXppXXXppXXX + # where X are the components and p are padding. + # One XXXpp group is one stride's worth of data. + assert stride % bytes_per_elem == 0 + elems_per_stride = stride // bytes_per_elem + num_elems = (accessor.count - 1) * elems_per_stride + component_nb + + array = np.frombuffer( + buffer_data, + dtype=np.dtype(dtype).newbyteorder('<'), + count=num_elems, + ) + assert array.strides[0] == bytes_per_elem + array = np.lib.stride_tricks.as_strided( + array, + shape=(accessor.count, component_nb), + strides=(stride, bytes_per_elem), + ) else: # No buffer view; initialize to zeros component_nb = gltf.component_nb_dict[accessor.type] - data = [ - (0,) * component_nb - for i in range(accessor.count) - ] + array = np.zeros((accessor.count, component_nb), dtype=dtype) if accessor.sparse: sparse_indices_obj = Accessor.from_dict({ @@ -123,6 +157,9 @@ class BinaryData(): 'componentType': accessor.sparse.indices.component_type, 'type': 'SCALAR', }) + sparse_indices = BinaryData.decode_accessor_obj(gltf, sparse_indices_obj) + sparse_indices = sparse_indices.reshape(len(sparse_indices)) + sparse_values_obj = Accessor.from_dict({ 'count': accessor.sparse.count, 'bufferView': accessor.sparse.values.buffer_view, @@ -130,31 +167,26 @@ class BinaryData(): 'componentType': accessor.component_type, 'type': accessor.type, }) - sparse_indices = BinaryData.get_data_from_accessor_obj(gltf, sparse_indices_obj) - sparse_values = BinaryData.get_data_from_accessor_obj(gltf, sparse_values_obj) + sparse_values = BinaryData.decode_accessor_obj(gltf, sparse_values_obj) - # Apply sparse - for i in range(accessor.sparse.count): - data[sparse_indices[i][0]] = sparse_values[i] + if not array.flags.writeable: + array = array.copy() + array[sparse_indices] = sparse_values # Normalization if accessor.normalized: - for idx, tuple in enumerate(data): - new_tuple = () - for i in tuple: - if accessor.component_type == 5120: - new_tuple += (max(float(i / 127.0 ), -1.0),) - elif accessor.component_type == 5121: - new_tuple += (float(i / 255.0),) - elif accessor.component_type == 5122: - new_tuple += (max(float(i / 32767.0), -1.0),) - elif accessor.component_type == 5123: - new_tuple += (i / 65535.0,) - else: - new_tuple += (float(i),) - data[idx] = new_tuple - - return data + if accessor.component_type == 5120: # int8 + array = np.maximum(-1.0, array / 127.0) + elif accessor.component_type == 5121: # uint8 + array = array / 255.0 + elif accessor.component_type == 5122: # int16 + array = np.maximum(-1.0, array / 32767.0) + elif accessor.component_type == 5123: # uint16 + array = array / 65535.0 + else: + array = array.astype(np.float64) + + return array @staticmethod def get_image_data(gltf, img_idx): |