io_scene_gltf2/blender/imp/gltf2_blender_animation_weight.py

   1 # SPDX-License-Identifier: Apache-2.0
   2 # Copyright 2018-2021 The glTF-Blender-IO authors.
   3
   4 import bpy
   5
   6 from ...io.imp.gltf2_io_binary import BinaryData
   7 from .gltf2_blender_animation_utils import make_fcurve
   8 from io_scene_gltf2.io.imp.gltf2_io_user_extensions import import_user_extensions
   9
  10
  11 class BlenderWeightAnim():
  12     """Blender ShapeKey Animation."""
  13     def __new__(cls, *args, **kwargs):
  14         raise RuntimeError("%s should not be instantiated" % cls)
  15
  16     @staticmethod
  17     def anim(gltf, anim_idx, vnode_id):
  18         """Manage animation."""
  19         vnode = gltf.vnodes[vnode_id]
  20
  21         node_idx = vnode.mesh_node_idx
  22
  23         import_user_extensions('gather_import_animation_weight_before_hook', gltf, vnode, gltf.data.animations[anim_idx])
  24
  25         if node_idx is None:
  26             return
  27
  28         node = gltf.data.nodes[node_idx]
  29         obj = vnode.blender_object
  30         fps = bpy.context.scene.render.fps
  31
  32         animation = gltf.data.animations[anim_idx]
  33
  34         if anim_idx not in node.animations.keys():
  35             return
  36
  37         for channel_idx in node.animations[anim_idx]:
  38             channel = animation.channels[channel_idx]
  39             if channel.target.path == "weights":
  40                 break
  41         else:
  42             return
  43
  44         name = animation.track_name + "_" + obj.name
  45         action = bpy.data.actions.new(name)
  46         action.id_root = "KEY"
  47         gltf.needs_stash.append((obj.data.shape_keys, action))
  48
  49         keys = BinaryData.get_data_from_accessor(gltf, animation.samplers[channel.sampler].input)
  50         values = BinaryData.get_data_from_accessor(gltf, animation.samplers[channel.sampler].output)
  51
  52         # retrieve number of targets
  53         pymesh = gltf.data.meshes[gltf.data.nodes[node_idx].mesh]
  54         nb_targets = len(pymesh.shapekey_names)
  55
  56         if animation.samplers[channel.sampler].interpolation == "CUBICSPLINE":
  57             offset = nb_targets
  58             stride = 3 * nb_targets
  59         else:
  60             offset = 0
  61             stride = nb_targets
  62
  63         coords = [0] * (2 * len(keys))
  64         coords[::2] = (key[0] * fps for key in keys)
  65
  66         for sk in range(nb_targets):
  67             if pymesh.shapekey_names[sk] is not None: # Do not animate shapekeys not created
  68                 coords[1::2] = (values[offset + stride * i + sk][0] for i in range(len(keys)))
  69                 kb_name = pymesh.shapekey_names[sk]
  70                 data_path = 'key_blocks["%s"].value' % bpy.utils.escape_identifier(kb_name)
  71
  72                 make_fcurve(
  73                     action,
  74                     coords,
  75                     data_path=data_path,
  76                     group_name="ShapeKeys",
  77                     interpolation=animation.samplers[channel.sampler].interpolation,
  78                 )
  79
  80                 # Expand weight range if needed
  81                 kb = obj.data.shape_keys.key_blocks[kb_name]
  82                 min_weight = min(coords[1:2])
  83                 max_weight = max(coords[1:2])
  84                 if min_weight < kb.slider_min: kb.slider_min = min_weight
  85                 if max_weight > kb.slider_max: kb.slider_max = max_weight
  86
  87         import_user_extensions('gather_import_animation_weight_after_hook', gltf, vnode, animation)