Depsgraph: cache effector relations, for performance and stability.

To find all effectors in the scene, we need to loop over all objects.
Doing this during depsgraph evaluation caused crashes because not all
objects are guaranteed to be evaluated yet.

To fix this, we now cache the relations as part of the dependency graph
build. As a bonus this also makes evaluation faster for big scenes,
since looping over all objects for each particle system is slow.

Fixes T55156.

1 files changed, 13 insertions, 15 deletions

diff --git a/source/blender/depsgraph/intern/depsgraph_build.cc b/source/blender/depsgraph/intern/depsgraph_build.cc
index 9c03e8c4ca3..da64478404b 100644
--- a/source/blender/depsgraph/intern/depsgraph_build.cc
+++ b/source/blender/depsgraph/intern/depsgraph_build.cc
@@ -357,31 +357,30 @@ void DEG_add_forcefield_relations(DepsNodeHandle *handle,
                                   const char *name)
 {
 	Depsgraph *depsgraph = DEG_get_graph_from_handle(handle);
-	ListBase *effectors = pdInitEffectors(depsgraph, scene, object, NULL, effector_weights, false);
-	if (effectors == NULL) {
-		return;
-	}
-	for (EffectorCache *eff = (EffectorCache*)effectors->first; eff; eff = eff->next) {
-		if (eff->ob != object && eff->pd->forcefield != skip_forcefield) {
-			DEG_add_object_relation(handle, eff->ob, DEG_OB_COMP_TRANSFORM, name);
-			if (eff->psys) {
-				DEG_add_object_relation(handle, eff->ob, DEG_OB_COMP_EVAL_PARTICLES, name);
+	DEG::Depsgraph *deg_graph = (DEG::Depsgraph *)depsgraph;
+	ListBase *relations = deg_build_effector_relations(deg_graph, effector_weights->group);
+
+	LISTBASE_FOREACH (EffectorRelation *, relation, relations) {
+		if (relation->ob != object && relation->pd->forcefield != skip_forcefield) {
+			DEG_add_object_relation(handle, relation->ob, DEG_OB_COMP_TRANSFORM, name);
+			if (relation->psys) {
+				DEG_add_object_relation(handle, relation->ob, DEG_OB_COMP_EVAL_PARTICLES, name);
 				/* TODO: remove this when/if EVAL_PARTICLES is sufficient
 				 * for up to date particles.
 				 */
-				DEG_add_object_relation(handle, eff->ob, DEG_OB_COMP_GEOMETRY, name);
+				DEG_add_object_relation(handle, relation->ob, DEG_OB_COMP_GEOMETRY, name);
 			}
-			if (eff->pd->forcefield == PFIELD_SMOKEFLOW && eff->pd->f_source) {
+			if (relation->pd->forcefield == PFIELD_SMOKEFLOW && relation->pd->f_source) {
 				DEG_add_object_relation(handle,
-				                        eff->pd->f_source,
+				                        relation->pd->f_source,
 				                        DEG_OB_COMP_TRANSFORM,
 				                        "Smoke Force Domain");
 				DEG_add_object_relation(handle,
-				                        eff->pd->f_source,
+				                        relation->pd->f_source,
 				                        DEG_OB_COMP_GEOMETRY,
 				                        "Smoke Force Domain");
 			}
-			if (add_absorption && (eff->pd->flag & PFIELD_VISIBILITY)) {
+			if (add_absorption && (relation->pd->flag & PFIELD_VISIBILITY)) {
 				DEG_add_collision_relations(handle,
 				                            scene,
 				                            object,
@@ -393,5 +392,4 @@ void DEG_add_forcefield_relations(DepsNodeHandle *handle,
 			}
 		}
 	}
-	pdEndEffectors(&effectors);
 }