FBX Import: Speed up shape keys with numpy #104491

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Bastien Montagne merged 1 commits from Mysteryem/blender-addons:fbx_import_shape_keys_np_pr into main 2023-04-03 14:49:04 +02:00
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@ -461,8 +461,9 @@ def add_vgroup_to_objects(vg_indices, vg_weights, vg_name, objects):
vg = obj.vertex_groups.get(vg_name)
if vg is None:
vg = obj.vertex_groups.new(name=vg_name)
vg_add = vg.add
for i, w in zip(vg_indices, vg_weights):
vg.add((i,), w, 'REPLACE')
vg_add((i,), w, 'REPLACE')
def blen_read_object_transform_preprocess(fbx_props, fbx_obj, rot_alt_mat, use_prepost_rot):
@ -1378,46 +1379,78 @@ def blen_read_geom(fbx_tmpl, fbx_obj, settings):
return mesh
def blen_read_shape(fbx_tmpl, fbx_sdata, fbx_bcdata, meshes, scene):
elem_name_utf8 = elem_name_ensure_class(fbx_sdata, b'Geometry')
indices = elem_prop_first(elem_find_first(fbx_sdata, b'Indexes'), default=())
dvcos = tuple(co for co in zip(*[iter(elem_prop_first(elem_find_first(fbx_sdata, b'Vertices'), default=()))] * 3))
# We completely ignore normals here!
weight = elem_prop_first(elem_find_first(fbx_bcdata, b'DeformPercent'), default=100.0) / 100.0
vgweights = tuple(vgw / 100.0 for vgw in elem_prop_first(elem_find_first(fbx_bcdata, b'FullWeights'), default=()))
def blen_read_shapes(fbx_tmpl, fbx_data, objects, me, scene):
if not fbx_data:
# No shape key data. Nothing to do.
return
# Special case, in case all weights are the same, FullWeight can have only one element - *sigh!*
nbr_indices = len(indices)
if len(vgweights) == 1 and nbr_indices > 1:
vgweights = (vgweights[0],) * nbr_indices
bl_vcos_dtype = np.single
me_vcos = np.empty(len(me.vertices) * 3, dtype=bl_vcos_dtype)
me.vertices.foreach_get("co", me_vcos)
me_vcos_vector_view = me_vcos.reshape(-1, 3)
assert(len(vgweights) == nbr_indices == len(dvcos))
create_vg = bool(set(vgweights) - {1.0})
objects = list({node.bl_obj for node in objects})
assert(objects)
keyblocks = []
bc_uuid_to_keyblocks = {}
for bc_uuid, fbx_sdata, fbx_bcdata in fbx_data:
elem_name_utf8 = elem_name_ensure_class(fbx_sdata, b'Geometry')
indices = elem_prop_first(elem_find_first(fbx_sdata, b'Indexes'))
dvcos = elem_prop_first(elem_find_first(fbx_sdata, b'Vertices'))
for me, objects in meshes:
vcos = tuple((idx, me.vertices[idx].co + Vector(dvco)) for idx, dvco in zip(indices, dvcos))
objects = list({node.bl_obj for node in objects})
assert(objects)
indices = parray_as_ndarray(indices) if indices else np.empty(0, dtype=data_types.ARRAY_INT32)
dvcos = parray_as_ndarray(dvcos) if dvcos else np.empty(0, dtype=data_types.ARRAY_FLOAT64)
# If there's not a whole number of vectors, trim off the remainder.
# 3 components per vector.
remainder = len(dvcos) % 3
if remainder:
dvcos = dvcos[:-remainder]
dvcos = dvcos.reshape(-1, 3)
# We completely ignore normals here!
weight = elem_prop_first(elem_find_first(fbx_bcdata, b'DeformPercent'), default=100.0) / 100.0
vgweights = elem_prop_first(elem_find_first(fbx_bcdata, b'FullWeights'))
vgweights = parray_as_ndarray(vgweights) if vgweights else np.empty(0, dtype=data_types.ARRAY_FLOAT64)
# Not doing the division in-place in-case it's possible for FBX shape keys to be used by more than one mesh.
vgweights = vgweights / 100.0
create_vg = (vgweights != 1.0).any()
# Special case, in case all weights are the same, FullWeight can have only one element - *sigh!*
nbr_indices = len(indices)
if len(vgweights) == 1 and nbr_indices > 1:
vgweights = np.full_like(indices, vgweights[0], dtype=vgweights.dtype)
assert(len(vgweights) == nbr_indices == len(dvcos))
# To add shape keys to the mesh, an Object using the mesh is needed.
if me.shape_keys is None:

Am wondering about how much speed differences we are talking about here... because this double codepath handling for a same thing has a significant impact on readability and maintainability, so would only consider it necessary if we are talking about real use-cases where the difference would be in tens of seconds on edge-cases, or at least seconds in more common cases?

Am wondering about how much speed differences we are talking about here... because this double codepath handling for a same thing has a significant impact on readability and maintainability, so would only consider it necessary if we are talking about real use-cases where the difference would be in tens of seconds on edge-cases, or at least seconds in more common cases?

Edge-cases only in the low single digit seconds slower I would say.
A 500,000 vertex .fbx with 60 shape keys that move only a single vertex each is about 1.9s slower to import without the iteration for me.

If getting rid of the iteration then I would add in a quick dvcos.any() check to only actually do the main work when the shape key contains at least one non-zero dvcos. I probably should have done that to begin with.

Edge-cases only in the low single digit seconds slower I would say. A 500,000 vertex .fbx with 60 shape keys that move only a single vertex each is about 1.9s slower to import without the iteration for me. If getting rid of the iteration then I would add in a quick `dvcos.any()` check to only actually do the main work when the shape key contains at least one non-zero dvcos. I probably should have done that to begin with.

Thanks, then indeed I think keeping a single codepath here is better overall.

Thanks, then indeed I think keeping a single codepath here is better overall.
objects[0].shape_key_add(name="Basis", from_mix=False)
kb = objects[0].shape_key_add(name=elem_name_utf8, from_mix=False)
me.shape_keys.use_relative = True # Should already be set as such.
for idx, co in vcos:
kb.data[idx].co[:] = co
# Only need to set the shape key co if there are any non-zero dvcos.
if dvcos.any():
shape_cos = me_vcos_vector_view.copy()
shape_cos[indices] += dvcos
kb.data.foreach_set("co", shape_cos.ravel())
kb.value = weight
# Add vgroup if necessary.
if create_vg:
vgoups = add_vgroup_to_objects(indices, vgweights, kb.name, objects)
# VertexGroup.add only allows sequences of int indices, but iterating the indices array directly would
# produce numpy scalars of types such as np.int32. The underlying memoryview of the indices array, however,
# does produce standard Python ints when iterated, so pass indices.data to add_vgroup_to_objects instead of
# indices.
# memoryviews tend to be faster to iterate than numpy arrays anyway, so vgweights.data is passed too.
add_vgroup_to_objects(indices.data, vgweights.data, kb.name, objects)
kb.vertex_group = kb.name
keyblocks.append(kb)
return keyblocks
bc_uuid_to_keyblocks.setdefault(bc_uuid, []).append(kb)
return bc_uuid_to_keyblocks
# --------
@ -2868,6 +2901,7 @@ def load(operator, context, filepath="",
def _():
fbx_tmpl = fbx_template_get((b'Geometry', b'KFbxShape'))
mesh_to_shapes = {}
for s_uuid, s_item in fbx_table_nodes.items():
fbx_sdata, bl_sdata = s_item = fbx_table_nodes.get(s_uuid, (None, None))
if fbx_sdata is None or fbx_sdata.id != b'Geometry' or fbx_sdata.props[2] != b'Shape':
@ -2880,8 +2914,6 @@ def load(operator, context, filepath="",
fbx_bcdata, _bl_bcdata = fbx_table_nodes.get(bc_uuid, (None, None))
if fbx_bcdata is None or fbx_bcdata.id != b'Deformer' or fbx_bcdata.props[2] != b'BlendShapeChannel':
continue
meshes = []
objects = []
for bs_uuid, bs_ctype in fbx_connection_map.get(bc_uuid, ()):
if bs_ctype.props[0] != b'OO':
continue
@ -2896,20 +2928,29 @@ def load(operator, context, filepath="",
continue
# Blenmeshes are assumed already created at that time!
assert(isinstance(bl_mdata, bpy.types.Mesh))
# And we have to find all objects using this mesh!
objects = []
for o_uuid, o_ctype in fbx_connection_map.get(m_uuid, ()):
if o_ctype.props[0] != b'OO':
continue
node = fbx_helper_nodes[o_uuid]
if node:
objects.append(node)
meshes.append((bl_mdata, objects))
# Group shapes by mesh so that each mesh only needs to be processed once for all of its shape
# keys.
if bl_mdata not in mesh_to_shapes:
# And we have to find all objects using this mesh!
objects = []
for o_uuid, o_ctype in fbx_connection_map.get(m_uuid, ()):
if o_ctype.props[0] != b'OO':
continue
node = fbx_helper_nodes[o_uuid]
if node:
objects.append(node)
shapes_list = []
mesh_to_shapes[bl_mdata] = (objects, shapes_list)
else:
shapes_list = mesh_to_shapes[bl_mdata][1]
shapes_list.append((bc_uuid, fbx_sdata, fbx_bcdata))
# BlendShape deformers are only here to connect BlendShapeChannels to meshes, nothing else to do.
# Iterate through each mesh and create its shape keys
for bl_mdata, (objects, shapes) in mesh_to_shapes.items():
for bc_uuid, keyblocks in blen_read_shapes(fbx_tmpl, shapes, objects, bl_mdata, scene).items():
# keyblocks is a list of tuples (mesh, keyblock) matching that shape/blendshapechannel, for animation.
keyblocks = blen_read_shape(fbx_tmpl, fbx_sdata, fbx_bcdata, meshes, scene)
blend_shape_channels[bc_uuid] = keyblocks
blend_shape_channels.setdefault(bc_uuid, []).extend(keyblocks)
_(); del _
if settings.use_subsurf: