Fix #131598: avoid relying on node tree update code being run before dependency graph is build

This avoids assuming that `BKE_ntree_update_main` has run on a node tree before
the depsgraph is build. The update code already finds the dependencies to
determine if a relations update is necessary or not. To avoid detecting these
dependencies again (which requires iterating over all the nested nodes), they
were cached on the node group so that they can be used when the depsgraph is
build.

However, since the update code does not run in all necessary cases yet
(#131598), this does not work currently. This patch fixes the situation by
removing the optimization of not having to find all dependencies again when the
depsgraph is build.

This optimization can be introduced again after we can be more sure that the
node tree update code runs whenever the node tree changes (which is what #131665
tries, but requires more discussion).

Pull Request: https://projects.blender.org/blender/blender/pulls/131685

source/blender/blenkernel/intern/node_tree_update.cc

@@ -870,8 +870,8 @@ class NodeTreeMainUpdater {
   void update_eval_dependencies(bNodeTree &ntree)
   {
     ntree.ensure_topology_cache();
-    nodes::GeometryNodesEvalDependencies new_deps;
-    nodes::gather_geometry_nodes_eval_dependencies(ntree, new_deps);
+    nodes::GeometryNodesEvalDependencies new_deps =
+        nodes::gather_geometry_nodes_eval_dependencies_with_cache(ntree);
 
     /* Check if the dependencies have changed. */
     if (!ntree.runtime->geometry_nodes_eval_dependencies ||

source/blender/modifiers/intern/MOD_nodes.cc

@@ -178,10 +178,8 @@ static void update_depsgraph(ModifierData *md, const ModifierUpdateDepsgraphCont
 
   DEG_add_node_tree_output_relation(ctx->node, nmd->node_group, "Nodes Modifier");
 
-  BLI_assert(nmd->node_group->runtime->geometry_nodes_eval_dependencies);
-  /* This intentionally makes a copy because a few extra dependencies are added below. */
   nodes::GeometryNodesEvalDependencies eval_deps =
-      *nmd->node_group->runtime->geometry_nodes_eval_dependencies;
+      nodes::gather_geometry_nodes_eval_dependencies_recursive(*nmd->node_group);
 
   /* Create dependencies to data-blocks referenced by the settings in the modifier. */
   find_dependencies_from_settings(nmd->settings, eval_deps);
@@ -252,8 +250,9 @@ static bool depends_on_time(Scene * /*scene*/, ModifierData *md)
       return true;
     }
   }
-  BLI_assert(tree->runtime->geometry_nodes_eval_dependencies);
-  return tree->runtime->geometry_nodes_eval_dependencies->time_dependent;
+  nodes::GeometryNodesEvalDependencies eval_deps =
+      nodes::gather_geometry_nodes_eval_dependencies_recursive(*nmd->node_group);
+  return eval_deps.time_dependent;
 }
 
 static void foreach_ID_link(ModifierData *md, Object *ob, IDWalkFunc walk, void *user_data)

source/blender/nodes/NOD_geometry_nodes_dependencies.hh

@@ -76,10 +76,16 @@ struct GeometryNodesEvalDependencies {
 };
 
 /**
- * Find all evaluation dependencies for the given node tree.
- * NOTE: It's assumed that all (indirectly) used node groups are updated already.
+ * Finds all evaluation dependencies for the given node. This does not include dependencies that
+ * are passed into the node group. It also may not contain all data-blocks referenced by the node
+ * tree if some of them can statically be detected to not be used by the evaluation.
  */
-void gather_geometry_nodes_eval_dependencies(bNodeTree &ntree,
-                                             GeometryNodesEvalDependencies &deps);
+GeometryNodesEvalDependencies gather_geometry_nodes_eval_dependencies_recursive(
+    const bNodeTree &ntree);
+/**
+ * Same as above, but assumes that dependencies are already cached on the referenced node groups.
+ */
+GeometryNodesEvalDependencies gather_geometry_nodes_eval_dependencies_with_cache(
+    const bNodeTree &ntree);
 
 }  // namespace blender::nodes

source/blender/nodes/intern/geometry_nodes_dependencies.cc

@@ -60,7 +60,7 @@ void GeometryNodesEvalDependencies::merge(const GeometryNodesEvalDependencies &o
   this->time_dependent |= other.time_dependent;
 }
 
-static void add_eval_dependencies_from_socket(bNodeSocket &socket,
+static void add_eval_dependencies_from_socket(const bNodeSocket &socket,
                                               GeometryNodesEvalDependencies &deps)
 {
   if (socket.is_input()) {
@@ -133,10 +133,13 @@ static bool node_needs_own_transform(const bNode &node)
   }
 }
 
-void gather_geometry_nodes_eval_dependencies(bNodeTree &ntree, GeometryNodesEvalDependencies &deps)
+static void gather_geometry_nodes_eval_dependencies(
+    const bNodeTree &ntree,
+    GeometryNodesEvalDependencies &deps,
+    FunctionRef<const GeometryNodesEvalDependencies *(const bNodeTree &group)> get_group_deps)
 {
   ntree.ensure_topology_cache();
-  for (bNodeSocket *socket : ntree.all_sockets()) {
+  for (const bNodeSocket *socket : ntree.all_sockets()) {
     add_eval_dependencies_from_socket(*socket, deps);
   }
   deps.needs_active_camera |= !ntree.nodes_by_type("GeometryNodeInputActiveCamera").is_empty();
@@ -147,8 +150,8 @@ void gather_geometry_nodes_eval_dependencies(bNodeTree &ntree, GeometryNodesEval
       continue;
     }
     const bNodeTree &group = *reinterpret_cast<const bNodeTree *>(node->id);
-    if (group.runtime->geometry_nodes_eval_dependencies) {
-      deps.merge(*group.runtime->geometry_nodes_eval_dependencies);
+    if (const GeometryNodesEvalDependencies *group_deps = get_group_deps(group)) {
+      deps.merge(*group_deps);
     }
   }
   for (const bNode *node : ntree.all_nodes()) {
@@ -156,4 +159,36 @@ void gather_geometry_nodes_eval_dependencies(bNodeTree &ntree, GeometryNodesEval
   }
 }
 
+GeometryNodesEvalDependencies gather_geometry_nodes_eval_dependencies_with_cache(
+    const bNodeTree &ntree)
+{
+  GeometryNodesEvalDependencies deps;
+  gather_geometry_nodes_eval_dependencies(ntree, deps, [](const bNodeTree &group) {
+    return group.runtime->geometry_nodes_eval_dependencies.get();
+  });
+  return deps;
+}
+
+static void gather_geometry_nodes_eval_dependencies_recursive_impl(
+    const bNodeTree &ntree, Map<const bNodeTree *, GeometryNodesEvalDependencies> &deps_by_tree)
+{
+  if (deps_by_tree.contains(&ntree)) {
+    return;
+  }
+  GeometryNodesEvalDependencies new_deps;
+  gather_geometry_nodes_eval_dependencies(ntree, new_deps, [&](const bNodeTree &group) {
+    gather_geometry_nodes_eval_dependencies_recursive_impl(group, deps_by_tree);
+    return &deps_by_tree.lookup(&group);
+  });
+  deps_by_tree.add(&ntree, std::move(new_deps));
+}
+
+GeometryNodesEvalDependencies gather_geometry_nodes_eval_dependencies_recursive(
+    const bNodeTree &ntree)
+{
+  Map<const bNodeTree *, GeometryNodesEvalDependencies> deps_by_tree;
+  gather_geometry_nodes_eval_dependencies_recursive_impl(ntree, deps_by_tree);
+  return deps_by_tree.lookup(&ntree);
+}
+
 }  // namespace blender::nodes