Add support for indirectly linked Geometry Nodes node trees

blender_asset_tracer/blendfile/iterators.py

@@ -60,3 +60,11 @@ def sequencer_strips(sequence_editor: BlendFileBlock) \
 
     sbase = sequence_editor.get_pointer((b'seqbase', b'first'))
     yield from iter_seqbase(sbase)
+
+
+def modifiers(object_block: BlendFileBlock) -> typing.Iterator[BlendFileBlock]:
+    """Generator, yield the object's modifiers."""
+
+    # 'ob->modifiers[...]'
+    mods = object_block.get_pointer((b'modifiers', b'first'))
+    yield from listbase(mods, next_path=(b'modifier', b'next'))

blender_asset_tracer/cdefs.py

@@ -47,6 +47,7 @@ eModifierType_WeightVGProximity = 38
 eModifierType_Ocean = 39
 eModifierType_MeshCache = 46
 eModifierType_MeshSequenceCache = 52
+eModifierType_Nodes = 57
 
 # DNA_particle_types.h
 PART_DRAW_OB = 7

blender_asset_tracer/trace/blocks2assets.py

@@ -139,8 +139,7 @@ def object_block(block: blendfile.BlendFileBlock) -> typing.Iterator[result.Bloc
     ctx = modifier_walkers.ModifierContext(owner=block)
 
     # 'ob->modifiers[...].filepath'
-    mods = block.get_pointer((b'modifiers', b'first'))
-    for mod_idx, block_mod in enumerate(iterators.listbase(mods, next_path=(b'modifier', b'next'))):
+    for mod_idx, block_mod in enumerate(iterators.modifiers(block)):
         block_name = b'%s.modifiers[%d]' % (block.id_name, mod_idx)
         mod_type = block_mod[b'modifier', b'type']
         log.debug('Tracing modifier %s, type=%d', block_name.decode(), mod_type)

blender_asset_tracer/trace/expanders.py

@@ -224,6 +224,14 @@ def _expand_object(block: blendfile.BlendFileBlock):
     for psystem in iterators.listbase(psystems):
         yield psystem.get_pointer(b'part')
 
+    # Modifiers can also refer to other datablocks, which should also get expanded.
+    for block_mod in iterators.modifiers(block):
+        mod_type = block_mod[b'modifier', b'type']
+        # Currently only node groups are supported. If the support should expand
+        # to more types, something more intelligent than this should be made.
+        if mod_type == cdefs.eModifierType_Nodes:
+            yield block_mod.get_pointer(b'node_group')
+
 
 @dna_code('PA')
 def _expand_particle_settings(block: blendfile.BlendFileBlock):