Geometry Nodes: Remove implicit realizing and conversion

This commit removes the implicit conversion from points to a mesh
that used to happen before the next modifier. It also removes the
implicit realizing of instances that happened before another modifier.

Now we have specific nodes for both of these operations, the
implicit conversions make less sense, and implicit instance
realizing has already been removed in other nodes.

This adds another geometry nodes modifier before modifiers that would
have realized instances implicitly before. Currently adding another
data-block during versioning after linking means that an assert needs
to be changed. That should be made unnecessary by T92333.

Differential Revision: https://developer.blender.org/D12722

1 files changed, 81 insertions, 0 deletions

diff --git a/source/blender/blenloader/intern/versioning_300.c b/source/blender/blenloader/intern/versioning_300.c
index 035642a561a..4c6b70982a4 100644
--- a/source/blender/blenloader/intern/versioning_300.c
+++ b/source/blender/blenloader/intern/versioning_300.c
@@ -55,6 +55,7 @@
 #include "BKE_idprop.h"
 #include "BKE_lib_id.h"
 #include "BKE_main.h"
+#include "BKE_modifier.h"
 #include "BKE_node.h"
 
 #include "RNA_access.h"
@@ -539,6 +540,54 @@ static void version_geometry_nodes_add_realize_instance_nodes(bNodeTree *ntree)
   }
 }
 
+/**
+ * The geometry nodes modifier used to realize instances for the next modifier implicitly. Now it
+ * is done with the realize instances node. It also used to convert meshes to point clouds
+ * automatically, which is also now done with a specific node.
+ */
+static bNodeTree *add_realize_node_tree(Main *bmain)
+{
+  bNodeTree *node_tree = ntreeAddTree(bmain, "Realize Instances 2.93 Legacy", "GeometryNodeTree");
+
+  ntreeAddSocketInterface(node_tree, SOCK_IN, "NodeSocketGeometry", "Geometry");
+  ntreeAddSocketInterface(node_tree, SOCK_OUT, "NodeSocketGeometry", "Geometry");
+
+  bNode *group_input = nodeAddStaticNode(NULL, node_tree, NODE_GROUP_INPUT);
+  group_input->locx = -400.0f;
+  bNode *group_output = nodeAddStaticNode(NULL, node_tree, NODE_GROUP_OUTPUT);
+  group_output->locx = 500.0f;
+  group_output->flag |= NODE_DO_OUTPUT;
+
+  bNode *join = nodeAddStaticNode(NULL, node_tree, GEO_NODE_JOIN_GEOMETRY);
+  join->locx = group_output->locx - 175.0f;
+  join->locy = group_output->locy;
+  bNode *conv = nodeAddStaticNode(NULL, node_tree, GEO_NODE_POINTS_TO_VERTICES);
+  conv->locx = join->locx - 175.0f;
+  conv->locy = join->locy - 70.0;
+  bNode *separate = nodeAddStaticNode(NULL, node_tree, GEO_NODE_SEPARATE_COMPONENTS);
+  separate->locx = join->locx - 350.0f;
+  separate->locy = join->locy + 50.0f;
+  bNode *realize = nodeAddStaticNode(NULL, node_tree, GEO_NODE_REALIZE_INSTANCES);
+  realize->locx = separate->locx - 200.0f;
+  realize->locy = join->locy;
+
+  nodeAddLink(node_tree, group_input, group_input->outputs.first, realize, realize->inputs.first);
+  nodeAddLink(node_tree, realize, realize->outputs.first, separate, separate->inputs.first);
+  nodeAddLink(node_tree, conv, conv->outputs.first, join, join->inputs.first);
+  nodeAddLink(node_tree, separate, BLI_findlink(&separate->outputs, 3), join, join->inputs.first);
+  nodeAddLink(node_tree, separate, BLI_findlink(&separate->outputs, 1), conv, conv->inputs.first);
+  nodeAddLink(node_tree, separate, BLI_findlink(&separate->outputs, 2), join, join->inputs.first);
+  nodeAddLink(node_tree, separate, separate->outputs.first, join, join->inputs.first);
+  nodeAddLink(node_tree, join, join->outputs.first, group_output, group_output->inputs.first);
+
+  LISTBASE_FOREACH (bNode *, node, &node_tree->nodes) {
+    nodeSetSelected(node, false);
+  }
+
+  ntreeUpdateTree(bmain, node_tree);
+  return node_tree;
+}
+
 void do_versions_after_linking_300(Main *bmain, ReportList *UNUSED(reports))
 {
   if (MAIN_VERSION_ATLEAST(bmain, 300, 0) && !MAIN_VERSION_ATLEAST(bmain, 300, 1)) {
@@ -672,6 +721,38 @@ void do_versions_after_linking_300(Main *bmain, ReportList *UNUSED(reports))
     }
   }
 
+  if (!MAIN_VERSION_ATLEAST(bmain, 300, 35)) {
+    /* Add a new modifier to realize instances from previous modifiers.
+     * Previously that was done automatically by geometry nodes. */
+    bNodeTree *realize_instances_node_tree = NULL;
+    LISTBASE_FOREACH (Object *, ob, &bmain->objects) {
+      LISTBASE_FOREACH_MUTABLE (ModifierData *, md, &ob->modifiers) {
+        if (md->type != eModifierType_Nodes) {
+          continue;
+        }
+        if (md->next == NULL) {
+          break;
+        }
+        if (md->next->type == eModifierType_Nodes) {
+          continue;
+        }
+        NodesModifierData *nmd = (NodesModifierData *)md;
+        if (nmd->node_group == NULL) {
+          continue;
+        }
+
+        NodesModifierData *new_nmd = (NodesModifierData *)BKE_modifier_new(eModifierType_Nodes);
+        STRNCPY(new_nmd->modifier.name, "Realize Instances 2.93 Legacy");
+        BKE_modifier_unique_name(&ob->modifiers, &new_nmd->modifier);
+        BLI_insertlinkafter(&ob->modifiers, md, new_nmd);
+        if (realize_instances_node_tree == NULL) {
+          realize_instances_node_tree = add_realize_node_tree(bmain);
+        }
+        new_nmd->node_group = realize_instances_node_tree;
+      }
+    }
+  }
+
   /**
    * Versioning code until next subversion bump goes here.
    *