Geometry Nodes: initial scattering and geometry nodes

This is the initial merge from the geometry-nodes branch.
Nodes:
* Attribute Math
* Boolean
* Edge Split
* Float Compare
* Object Info
* Point Distribute
* Point Instance
* Random Attribute
* Random Float
* Subdivision Surface
* Transform
* Triangulate

It includes the initial evaluation of geometry node groups in the Geometry Nodes modifier.

Notes on the Generic attribute access API

The API adds an indirection for attribute access. That has the following benefits:
* Most code does not have to care about how an attribute is stored internally.
  This is mainly necessary, because we have to deal with "legacy" attributes
  such as vertex weights and attributes that are embedded into other structs
  such as vertex positions.
* When reading from an attribute, we generally don't care what domain the
  attribute is stored on. So we want to abstract away the interpolation that
  that adapts attributes from one domain to another domain (this is not
  actually implemented yet).

Other possible improvements for later iterations include:
* Actually implement interpolation between domains.
* Don't use inheritance for the different attribute types. A single class for read
  access and one for write access might be enough, because we know all the ways
  in which attributes are stored internally. We don't want more different internal
  structures in the future. On the contrary, ideally we can consolidate the different
  storage formats in the future to reduce the need for this indirection.
* Remove the need for heap allocations when creating attribute accessors.

It includes commits from:
* Dalai Felinto
* Hans Goudey
* Jacques Lucke
* Léo Depoix

7 files changed, 332 insertions, 97 deletions

diff --git a/source/blender/makesrna/RNA_access.h b/source/blender/makesrna/RNA_access.h
index 6dfd7b0fdf5..bc25a404de8 100644
--- a/source/blender/makesrna/RNA_access.h
+++ b/source/blender/makesrna/RNA_access.h
@@ -566,10 +566,11 @@ extern StructRNA RNA_SimpleDeformModifier;
 extern StructRNA RNA_SimplifyGpencilModifier;
 extern StructRNA RNA_Simulation;
 #ifdef WITH_GEOMETRY_NODES
-extern StructRNA RNA_SimulationModifier;
+extern StructRNA RNA_NodesModifier;
+extern StructRNA RNA_NodesModifierSettings;
 #endif
-extern StructRNA RNA_SimulationNode;
-extern StructRNA RNA_SimulationNodeTree;
+extern StructRNA RNA_GeometryNode;
+extern StructRNA RNA_GeometryNodeTree;
 extern StructRNA RNA_SkinModifier;
 extern StructRNA RNA_SmoothGpencilModifier;
 extern StructRNA RNA_SmoothModifier;
diff --git a/source/blender/makesrna/intern/CMakeLists.txt b/source/blender/makesrna/intern/CMakeLists.txt
index d638d6f66cc..3ebbb98934e 100644
--- a/source/blender/makesrna/intern/CMakeLists.txt
+++ b/source/blender/makesrna/intern/CMakeLists.txt
@@ -373,6 +373,7 @@ blender_include_dirs(
   ../../ikplugin
   ../../imbuf
   ../../makesdna
+  ../../modifiers
   ../../nodes/
   ../../sequencer
   ../../simulation
diff --git a/source/blender/makesrna/intern/rna_access.c b/source/blender/makesrna/intern/rna_access.c
index ceccccc3291..4991f34c3f6 100644
--- a/source/blender/makesrna/intern/rna_access.c
+++ b/source/blender/makesrna/intern/rna_access.c
@@ -1160,8 +1160,8 @@ PropertySubType RNA_property_subtype(PropertyRNA *prop)
   if (prop->magic != RNA_MAGIC) {
     IDProperty *idprop = (IDProperty *)prop;
 
-    /* Restrict to arrays only for now for performance reasons. */
-    if (idprop->type == IDP_ARRAY && ELEM(idprop->subtype, IDP_INT, IDP_FLOAT, IDP_DOUBLE)) {
+    if (ELEM(idprop->type, IDP_INT, IDP_FLOAT, IDP_DOUBLE) ||
+        ((idprop->type == IDP_ARRAY) && ELEM(idprop->subtype, IDP_INT, IDP_FLOAT, IDP_DOUBLE))) {
       const IDProperty *idp_ui = rna_idproperty_ui(prop);
 
       if (idp_ui) {
diff --git a/source/blender/makesrna/intern/rna_attribute.c b/source/blender/makesrna/intern/rna_attribute.c
index 7f0ab2df70d..ad615026343 100644
--- a/source/blender/makesrna/intern/rna_attribute.c
+++ b/source/blender/makesrna/intern/rna_attribute.c
@@ -50,13 +50,12 @@ const EnumPropertyItem rna_enum_attribute_type_items[] = {
 const EnumPropertyItem rna_enum_attribute_domain_items[] = {
     /* Not implement yet */
     // {ATTR_DOMAIN_GEOMETRY, "GEOMETRY", 0, "Geometry", "Attribute on (whole) geometry"},
-    {ATTR_DOMAIN_VERTEX, "VERTEX", 0, "Vertex", "Attribute on mesh vertex"},
+    {ATTR_DOMAIN_POINT, "POINT", 0, "Point", "Attribute on point"},
     {ATTR_DOMAIN_EDGE, "EDGE", 0, "Edge", "Attribute on mesh edge"},
     {ATTR_DOMAIN_CORNER, "CORNER", 0, "Corner", "Attribute on mesh polygon corner"},
     {ATTR_DOMAIN_POLYGON, "POLYGON", 0, "Polygon", "Attribute on mesh polygons"},
     /* Not implement yet */
     // {ATTR_DOMAIN_GRIDS, "GRIDS", 0, "Grids", "Attribute on mesh multires grids"},
-    {ATTR_DOMAIN_POINT, "POINT", 0, "Point", "Attribute on point"},
     {ATTR_DOMAIN_CURVE, "CURVE", 0, "Curve", "Attribute on hair curve"},
     {0, NULL, 0, NULL, NULL},
 };
@@ -117,7 +116,7 @@ const EnumPropertyItem *rna_enum_attribute_domain_itemf(ID *id, bool *r_free)
     if (id_type == ID_HA && !ELEM(domain_item->value, ATTR_DOMAIN_POINT, ATTR_DOMAIN_CURVE)) {
       continue;
     }
-    if (id_type == ID_ME && ELEM(domain_item->value, ATTR_DOMAIN_POINT, ATTR_DOMAIN_CURVE)) {
+    if (id_type == ID_ME && ELEM(domain_item->value, ATTR_DOMAIN_CURVE)) {
       continue;
     }
 
@@ -619,7 +618,7 @@ static void rna_def_attribute_group(BlenderRNA *brna)
   parm = RNA_def_enum(func,
                       "domain",
                       rna_enum_attribute_domain_items,
-                      ATTR_DOMAIN_VERTEX,
+                      ATTR_DOMAIN_POINT,
                       "Domain",
                       "Type of element that attribute is stored on");
   RNA_def_parameter_flags(parm, 0, PARM_REQUIRED);
diff --git a/source/blender/makesrna/intern/rna_modifier.c b/source/blender/makesrna/intern/rna_modifier.c
index c0f3197b2d1..09c1869b84b 100644
--- a/source/blender/makesrna/intern/rna_modifier.c
+++ b/source/blender/makesrna/intern/rna_modifier.c
@@ -29,7 +29,6 @@
 #include "DNA_object_force_types.h"
 #include "DNA_object_types.h"
 #include "DNA_scene_types.h"
-#include "DNA_simulation_types.h"
 
 #include "MEM_guardedalloc.h"
 
@@ -43,6 +42,7 @@
 #include "BKE_dynamicpaint.h"
 #include "BKE_effect.h"
 #include "BKE_fluid.h" /* For BKE_fluid_modifier_free & BKE_fluid_modifier_create_type_data */
+#include "BKE_idprop.h"
 #include "BKE_mesh_mapping.h"
 #include "BKE_mesh_remap.h"
 #include "BKE_multires.h"
@@ -57,6 +57,8 @@
 #include "WM_api.h"
 #include "WM_types.h"
 
+#include "MOD_nodes.h"
+
 const EnumPropertyItem rna_enum_object_modifier_type_items[] = {
     {0, "", 0, N_("Modify"), ""},
     {eModifierType_DataTransfer,
@@ -141,6 +143,7 @@ const EnumPropertyItem rna_enum_object_modifier_type_items[] = {
      ICON_MOD_EDGESPLIT,
      "Edge Split",
      "Split away joined faces at the edges"},
+    {eModifierType_Nodes, "NODES", ICON_NODETREE, "Geometry Nodes", ""},
     {eModifierType_Mask,
      "MASK",
      ICON_MOD_MASK,
@@ -305,11 +308,6 @@ const EnumPropertyItem rna_enum_object_modifier_type_items[] = {
      "Spawn particles from the shape"},
     {eModifierType_Softbody, "SOFT_BODY", ICON_MOD_SOFT, "Soft Body", ""},
     {eModifierType_Surface, "SURFACE", ICON_MODIFIER, "Surface", ""},
-    {eModifierType_Simulation,
-     "SIMULATION",
-     ICON_PHYSICS,
-     "Simulation",
-     ""}, /* TODO: Use correct icon. */
     {0, NULL, 0, NULL, NULL},
 };
 
@@ -1588,6 +1586,37 @@ static int rna_MeshSequenceCacheModifier_read_velocity_get(PointerRNA *ptr)
 #  endif
 }
 
+static bool rna_NodesModifier_node_group_poll(PointerRNA *ptr, PointerRNA value)
+{
+  NodesModifierData *nmd = ptr->data;
+  bNodeTree *ntree = value.data;
+  UNUSED_VARS(nmd, ntree);
+  return true;
+}
+
+static void rna_NodesModifier_node_group_update(Main *bmain, Scene *scene, PointerRNA *ptr)
+{
+  Object *object = (Object *)ptr->owner_id;
+  NodesModifierData *nmd = ptr->data;
+  rna_Modifier_dependency_update(bmain, scene, ptr);
+  MOD_nodes_update_interface(object, nmd);
+}
+
+static IDProperty *rna_NodesModifierSettings_properties(PointerRNA *ptr, bool create)
+{
+  NodesModifierSettings *settings = ptr->data;
+  if (create && settings->properties == NULL) {
+    IDPropertyTemplate val = {0};
+    settings->properties = IDP_New(IDP_GROUP, &val, "Nodes Modifier Settings");
+  }
+  return settings->properties;
+}
+
+static char *rna_NodesModifierSettings_path(PointerRNA *UNUSED(ptr))
+{
+  return BLI_strdup("settings");
+}
+
 #else
 
 static void rna_def_property_subdivision_common(StructRNA *srna)
@@ -6907,18 +6936,43 @@ static void rna_def_modifier_weightednormal(BlenderRNA *brna)
 }
 
 #  ifdef WITH_GEOMETRY_NODES
-static void rna_def_modifier_simulation(BlenderRNA *brna)
+static void rna_def_modifier_nodes_settings(BlenderRNA *brna)
 {
   StructRNA *srna;
 
-  srna = RNA_def_struct(brna, "SimulationModifier", "Modifier");
-  RNA_def_struct_ui_text(srna, "Simulation Modifier", "");
-  RNA_def_struct_sdna(srna, "SimulationModifierData");
-  RNA_def_struct_ui_icon(srna, ICON_PHYSICS); /* TODO: Use correct icon. */
+  srna = RNA_def_struct(brna, "NodesModifierSettings", NULL);
+  RNA_def_struct_nested(brna, srna, "NodesModifier");
+  RNA_def_struct_path_func(srna, "rna_NodesModifierSettings_path");
+  RNA_def_struct_ui_text(
+      srna, "Nodes Modifier Settings", "Settings that are passed into the node group");
+  RNA_def_struct_idprops_func(srna, "rna_NodesModifierSettings_properties");
+}
+
+static void rna_def_modifier_nodes(BlenderRNA *brna)
+{
+  StructRNA *srna;
+  PropertyRNA *prop;
+
+  srna = RNA_def_struct(brna, "NodesModifier", "Modifier");
+  RNA_def_struct_ui_text(srna, "Nodes Modifier", "");
+  RNA_def_struct_sdna(srna, "NodesModifierData");
+  RNA_def_struct_ui_icon(srna, ICON_MESH_DATA); /* TODO: Use correct icon. */
 
   RNA_define_lib_overridable(true);
 
+  prop = RNA_def_property(srna, "node_group", PROP_POINTER, PROP_NONE);
+  RNA_def_property_ui_text(prop, "Node Group", "Node group that controls what this modifier does");
+  RNA_def_property_pointer_funcs(prop, NULL, NULL, NULL, "rna_NodesModifier_node_group_poll");
+  RNA_def_property_flag(prop, PROP_EDITABLE);
+  RNA_def_property_update(prop, 0, "rna_NodesModifier_node_group_update");
+
+  prop = RNA_def_property(srna, "settings", PROP_POINTER, PROP_NONE);
+  RNA_def_property_flag(prop, PROP_NEVER_NULL);
+  RNA_def_property_ui_text(prop, "Settings", "Settings that are passed into the node group");
+
   RNA_define_lib_overridable(false);
+
+  rna_def_modifier_nodes_settings(brna);
 }
 #  endif
 
@@ -7277,7 +7331,7 @@ void RNA_def_modifier(BlenderRNA *brna)
   rna_def_modifier_surfacedeform(brna);
   rna_def_modifier_weightednormal(brna);
 #  ifdef WITH_GEOMETRY_NODES
-  rna_def_modifier_simulation(brna);
+  rna_def_modifier_nodes(brna);
 #  endif
   rna_def_modifier_mesh_to_volume(brna);
   rna_def_modifier_volume_displace(brna);
diff --git a/source/blender/makesrna/intern/rna_nodetree.c b/source/blender/makesrna/intern/rna_nodetree.c
index 67bb5e89254..11d57919fb1 100644
--- a/source/blender/makesrna/intern/rna_nodetree.c
+++ b/source/blender/makesrna/intern/rna_nodetree.c
@@ -36,9 +36,9 @@
 #include "DNA_texture_types.h"
 
 #include "BKE_animsys.h"
+#include "BKE_attribute.h"
 #include "BKE_image.h"
 #include "BKE_node.h"
-#include "BKE_simulation.h"
 #include "BKE_texture.h"
 
 #include "RNA_access.h"
@@ -369,6 +369,72 @@ static const EnumPropertyItem prop_shader_output_target_items[] = {
     {SHD_OUTPUT_CYCLES, "CYCLES", 0, "Cycles", "Use shaders for Cycles renderer"},
     {0, NULL, 0, NULL, NULL},
 };
+
+static const EnumPropertyItem rna_node_geometry_boolean_method_items[] = {
+    {GEO_NODE_BOOLEAN_INTERSECT,
+     "INTERSECT",
+     0,
+     "Intersect",
+     "Keep the part of the mesh that is common between all operands"},
+    {GEO_NODE_BOOLEAN_UNION, "UNION", 0, "Union", "Combine meshes in an additive way"},
+    {GEO_NODE_BOOLEAN_DIFFERENCE,
+     "DIFFERENCE",
+     0,
+     "Difference",
+     "Combine meshes in a subtractive way"},
+    {0, NULL, 0, NULL, NULL},
+};
+
+static const EnumPropertyItem rna_node_geometry_triangulate_quad_method_items[] = {
+    {GEO_NODE_TRIANGULATE_QUAD_BEAUTY,
+     "BEAUTY",
+     0,
+     "Beauty",
+     "Split the quads in nice triangles, slower method"},
+    {GEO_NODE_TRIANGULATE_QUAD_FIXED,
+     "FIXED",
+     0,
+     "Fixed",
+     "Split the quads on the first and third vertices"},
+    {GEO_NODE_TRIANGULATE_QUAD_ALTERNATE,
+     "FIXED_ALTERNATE",
+     0,
+     "Fixed Alternate",
+     "Split the quads on the 2nd and 4th vertices"},
+    {GEO_NODE_TRIANGULATE_QUAD_SHORTEDGE,
+     "SHORTEST_DIAGONAL",
+     0,
+     "Shortest Diagonal",
+     "Split the quads based on the distance between the vertices"},
+    {0, NULL, 0, NULL, NULL},
+};
+
+static const EnumPropertyItem rna_node_geometry_triangulate_ngon_method_items[] = {
+    {GEO_NODE_TRIANGULATE_NGON_BEAUTY,
+     "BEAUTY",
+     0,
+     "Beauty",
+     "Arrange the new triangles evenly (slow)"},
+    {GEO_NODE_TRIANGULATE_NGON_EARCLIP,
+     "CLIP",
+     0,
+     "Clip",
+     "Split the polygons with an ear clipping algorithm"},
+    {0, NULL, 0, NULL, NULL},
+};
+
+static const EnumPropertyItem rna_node_geometry_attribute_input_a_items[] = {
+    {0, "FLOAT", 0, "Float", ""},
+    {GEO_NODE_USE_ATTRIBUTE_A, "ATTRIBUTE", 0, "Attribute", ""},
+    {0, NULL, 0, NULL, NULL},
+};
+
+static const EnumPropertyItem rna_node_geometry_attribute_input_b_items[] = {
+    {0, "FLOAT", 0, "Float", ""},
+    {GEO_NODE_USE_ATTRIBUTE_B, "ATTRIBUTE", 0, "Attribute", ""},
+    {0, NULL, 0, NULL, NULL},
+};
+
 #endif
 
 #ifdef RNA_RUNTIME
@@ -727,9 +793,9 @@ static const EnumPropertyItem *rna_node_static_type_itemf(bContext *UNUSED(C),
 #  undef DefNode
   }
 
-  if (RNA_struct_is_a(ptr->type, &RNA_SimulationNode)) {
+  if (RNA_struct_is_a(ptr->type, &RNA_GeometryNode)) {
 #  define DefNode(Category, ID, DefFunc, EnumName, StructName, UIName, UIDesc) \
-    if (STREQ(#Category, "SimulationNode")) { \
+    if (STREQ(#Category, "GeometryNode")) { \
       tmp.value = ID; \
       tmp.identifier = EnumName; \
       tmp.name = UIName; \
@@ -1774,6 +1840,61 @@ static StructRNA *rna_Node_register(Main *bmain,
   return nt->rna_ext.srna;
 }
 
+static const EnumPropertyItem *itemf_function_check(
+    const EnumPropertyItem *original_item_array,
+    bool (*value_supported)(const EnumPropertyItem *item))
+{
+  EnumPropertyItem *item_array = NULL;
+  int items_len = 0;
+
+  for (const EnumPropertyItem *item = original_item_array; item->identifier != NULL; item++) {
+    if (value_supported(item)) {
+      RNA_enum_item_add(&item_array, &items_len, item);
+    }
+  }
+
+  RNA_enum_item_end(&item_array, &items_len);
+  return item_array;
+}
+
+static bool attribute_random_type_supported(const EnumPropertyItem *item)
+{
+  return ELEM(item->value, CD_PROP_FLOAT, CD_PROP_FLOAT3);
+}
+static const EnumPropertyItem *rna_GeometryNodeAttributeRandom_type_itemf(
+    bContext *UNUSED(C), PointerRNA *UNUSED(ptr), PropertyRNA *UNUSED(prop), bool *r_free)
+{
+  *r_free = true;
+  return itemf_function_check(rna_enum_attribute_type_items, attribute_random_type_supported);
+}
+
+static bool attribute_random_domain_supported(const EnumPropertyItem *item)
+{
+  return item->value == ATTR_DOMAIN_POINT;
+}
+static const EnumPropertyItem *rna_GeometryNodeAttributeRandom_domain_itemf(
+    bContext *UNUSED(C), PointerRNA *UNUSED(ptr), PropertyRNA *UNUSED(prop), bool *r_free)
+{
+  *r_free = true;
+  return itemf_function_check(rna_enum_attribute_domain_items, attribute_random_domain_supported);
+}
+
+static bool attribute_math_operation_supported(const EnumPropertyItem *item)
+{
+  return ELEM(item->value,
+              NODE_MATH_ADD,
+              NODE_MATH_SUBTRACT,
+              NODE_MATH_MULTIPLY,
+              NODE_MATH_DIVIDE) &&
+         (item->identifier[0] != '\0');
+}
+static const EnumPropertyItem *rna_GeometryNodeAttributeMath_operation_itemf(
+    bContext *UNUSED(C), PointerRNA *UNUSED(ptr), PropertyRNA *UNUSED(prop), bool *r_free)
+{
+  *r_free = true;
+  return itemf_function_check(rna_enum_node_math_items, attribute_math_operation_supported);
+}
+
 static StructRNA *rna_ShaderNode_register(Main *bmain,
                                           ReportList *reports,
                                           void *data,
@@ -1840,16 +1961,16 @@ static StructRNA *rna_TextureNode_register(Main *bmain,
   return nt->rna_ext.srna;
 }
 
-static StructRNA *rna_SimulationNode_register(Main *bmain,
-                                              ReportList *reports,
-                                              void *data,
-                                              const char *identifier,
-                                              StructValidateFunc validate,
-                                              StructCallbackFunc call,
-                                              StructFreeFunc free)
+static StructRNA *rna_GeometryNode_register(Main *bmain,
+                                            ReportList *reports,
+                                            void *data,
+                                            const char *identifier,
+                                            StructValidateFunc validate,
+                                            StructCallbackFunc call,
+                                            StructFreeFunc free)
 {
   bNodeType *nt = rna_Node_register_base(
-      bmain, reports, &RNA_SimulationNode, data, identifier, validate, call, free);
+      bmain, reports, &RNA_GeometryNode, data, identifier, validate, call, free);
   if (!nt) {
     return NULL;
   }
@@ -2812,6 +2933,7 @@ static void rna_NodeSocketStandard_value_and_relation_update(struct bContext *C,
   bNodeTree *ntree = (bNodeTree *)ptr->owner_id;
   Main *bmain = CTX_data_main(C);
   ntreeUpdateTree(bmain, ntree);
+  DEG_relations_tag_update(bmain);
 }
 
 /* ******** Node Types ******** */
@@ -3697,7 +3819,16 @@ static void rna_ShaderNode_socket_update(Main *bmain, Scene *scene, PointerRNA *
   rna_Node_update(bmain, scene, ptr);
 }
 
-static void rna_FunctionNode_socket_update(Main *bmain, Scene *scene, PointerRNA *ptr)
+static void rna_Node_socket_update(Main *bmain, Scene *scene, PointerRNA *ptr)
+{
+  bNodeTree *ntree = (bNodeTree *)ptr->owner_id;
+  bNode *node = (bNode *)ptr->data;
+
+  nodeUpdate(ntree, node);
+  rna_Node_update(bmain, scene, ptr);
+}
+
+static void rna_GeometryNode_socket_update(Main *bmain, Scene *scene, PointerRNA *ptr)
 {
   bNodeTree *ntree = (bNodeTree *)ptr->owner_id;
   bNode *node = (bNode *)ptr->data;
@@ -4149,7 +4280,7 @@ static void def_boolean_math(StructRNA *srna)
   RNA_def_property_enum_sdna(prop, NULL, "custom1");
   RNA_def_property_enum_items(prop, rna_enum_node_boolean_math_items);
   RNA_def_property_ui_text(prop, "Operation", "");
-  RNA_def_property_update(prop, NC_NODE | NA_EDITED, "rna_FunctionNode_socket_update");
+  RNA_def_property_update(prop, NC_NODE | NA_EDITED, "rna_Node_socket_update");
 }
 
 static void def_float_compare(StructRNA *srna)
@@ -4160,7 +4291,7 @@ static void def_float_compare(StructRNA *srna)
   RNA_def_property_enum_sdna(prop, NULL, "custom1");
   RNA_def_property_enum_items(prop, rna_enum_node_float_compare_items);
   RNA_def_property_ui_text(prop, "Operation", "");
-  RNA_def_property_update(prop, NC_NODE | NA_EDITED, "rna_FunctionNode_socket_update");
+  RNA_def_property_update(prop, NC_NODE | NA_EDITED, "rna_Node_socket_update");
 }
 
 static void def_fn_switch(StructRNA *srna)
@@ -4171,7 +4302,7 @@ static void def_fn_switch(StructRNA *srna)
   RNA_def_property_enum_sdna(prop, NULL, "custom1");
   RNA_def_property_enum_items(prop, node_socket_data_type_items);
   RNA_def_property_ui_text(prop, "Data Type", "Data type for inputs and outputs");
-  RNA_def_property_update(prop, NC_NODE | NA_EDITED, "rna_FunctionNode_socket_update");
+  RNA_def_property_update(prop, NC_NODE | NA_EDITED, "rna_Node_socket_update");
 }
 
 static void def_vector_math(StructRNA *srna)
@@ -8140,6 +8271,103 @@ static void def_tex_bricks(StructRNA *srna)
   RNA_def_property_update(prop, NC_NODE | NA_EDITED, "rna_Node_update");
 }
 
+/* -- Geometry Nodes --------------------------------------------------------- */
+
+static void def_geo_boolean(StructRNA *srna)
+{
+  PropertyRNA *prop;
+
+  prop = RNA_def_property(srna, "operation", PROP_ENUM, PROP_NONE);
+  RNA_def_property_enum_sdna(prop, NULL, "custom1");
+  RNA_def_property_enum_items(prop, rna_node_geometry_boolean_method_items);
+  RNA_def_property_enum_default(prop, GEO_NODE_BOOLEAN_INTERSECT);
+  RNA_def_property_ui_text(prop, "Operation", "");
+  RNA_def_property_update(prop, NC_NODE | NA_EDITED, "rna_Node_update");
+}
+
+static void def_geo_triangulate(StructRNA *srna)
+{
+  PropertyRNA *prop;
+
+  prop = RNA_def_property(srna, "quad_method", PROP_ENUM, PROP_NONE);
+  RNA_def_property_enum_sdna(prop, NULL, "custom1");
+  RNA_def_property_enum_items(prop, rna_node_geometry_triangulate_quad_method_items);
+  RNA_def_property_enum_default(prop, GEO_NODE_TRIANGULATE_QUAD_SHORTEDGE);
+  RNA_def_property_ui_text(prop, "Quad Method", "Method for splitting the quads into triangles");
+  RNA_def_property_update(prop, NC_NODE | NA_EDITED, "rna_Node_update");
+
+  prop = RNA_def_property(srna, "ngon_method", PROP_ENUM, PROP_NONE);
+  RNA_def_property_enum_sdna(prop, NULL, "custom2");
+  RNA_def_property_enum_items(prop, rna_node_geometry_triangulate_ngon_method_items);
+  RNA_def_property_enum_default(prop, GEO_NODE_TRIANGULATE_NGON_BEAUTY);
+  RNA_def_property_ui_text(
+      prop, "Polygon Method", "Method for splitting the polygons into triangles");
+  RNA_def_property_update(prop, NC_NODE | NA_EDITED, "rna_Node_update");
+}
+
+/**
+ * \note Passing the item functions as arguments here allows reusing the same
+ * original list of items from Attribute RNA.
+ */
+static void def_geo_attribute_create_common(StructRNA *srna,
+                                            const char *type_items_func,
+                                            const char *domain_items_func)
+{
+  PropertyRNA *prop;
+
+  prop = RNA_def_property(srna, "data_type", PROP_ENUM, PROP_NONE);
+  RNA_def_property_enum_sdna(prop, NULL, "custom1");
+  RNA_def_property_enum_items(prop, rna_enum_attribute_type_items);
+  if (type_items_func != NULL) {
+    RNA_def_property_enum_funcs(prop, NULL, NULL, type_items_func);
+  }
+  RNA_def_property_enum_default(prop, CD_PROP_FLOAT);
+  RNA_def_property_ui_text(prop, "Data Type", "Type of data stored in attribute");
+  RNA_def_property_update(prop, NC_NODE | NA_EDITED, "rna_GeometryNode_socket_update");
+
+  prop = RNA_def_property(srna, "domain", PROP_ENUM, PROP_NONE);
+  RNA_def_property_enum_sdna(prop, NULL, "custom2");
+  RNA_def_property_enum_items(prop, rna_enum_attribute_domain_items);
+  if (domain_items_func != NULL) {
+    RNA_def_property_enum_funcs(prop, NULL, NULL, domain_items_func);
+  }
+  RNA_def_property_enum_default(prop, ATTR_DOMAIN_POINT);
+  RNA_def_property_ui_text(prop, "Domain", "");
+  RNA_def_property_update(prop, NC_NODE | NA_EDITED, "rna_Node_update");
+}
+
+static void def_geo_random_attribute(StructRNA *srna)
+{
+  def_geo_attribute_create_common(srna,
+                                  "rna_GeometryNodeAttributeRandom_type_itemf",
+                                  "rna_GeometryNodeAttributeRandom_domain_itemf");
+}
+
+static void def_geo_attribute_math(StructRNA *srna)
+{
+  PropertyRNA *prop;
+
+  prop = RNA_def_property(srna, "operation", PROP_ENUM, PROP_NONE);
+  RNA_def_property_enum_sdna(prop, NULL, "custom1");
+  RNA_def_property_enum_items(prop, rna_enum_node_math_items);
+  RNA_def_property_enum_funcs(prop, NULL, NULL, "rna_GeometryNodeAttributeMath_operation_itemf");
+  RNA_def_property_enum_default(prop, NODE_MATH_ADD);
+  RNA_def_property_ui_text(prop, "Operation", "");
+  RNA_def_property_update(prop, NC_NODE | NA_EDITED, "rna_Node_update");
+
+  prop = RNA_def_property(srna, "input_type_a", PROP_ENUM, PROP_NONE);
+  RNA_def_property_enum_bitflag_sdna(prop, NULL, "custom2");
+  RNA_def_property_enum_items(prop, rna_node_geometry_attribute_input_a_items);
+  RNA_def_property_ui_text(prop, "Input Type A", "");
+  RNA_def_property_update(prop, NC_NODE | NA_EDITED, "rna_Node_socket_update");
+
+  prop = RNA_def_property(srna, "input_type_b", PROP_ENUM, PROP_NONE);
+  RNA_def_property_enum_bitflag_sdna(prop, NULL, "custom2");
+  RNA_def_property_enum_items(prop, rna_node_geometry_attribute_input_b_items);
+  RNA_def_property_ui_text(prop, "Input Type B", "");
+  RNA_def_property_update(prop, NC_NODE | NA_EDITED, "rna_Node_socket_update");
+}
+
 /* -------------------------------------------------------------------------- */
 
 static void rna_def_shader_node(BlenderRNA *brna)
@@ -8177,14 +8405,14 @@ static void rna_def_texture_node(BlenderRNA *brna)
   RNA_def_struct_register_funcs(srna, "rna_TextureNode_register", "rna_Node_unregister", NULL);
 }
 
-static void rna_def_simulation_node(BlenderRNA *brna)
+static void rna_def_geometry_node(BlenderRNA *brna)
 {
   StructRNA *srna;
 
-  srna = RNA_def_struct(brna, "SimulationNode", "NodeInternal");
-  RNA_def_struct_ui_text(srna, "Simulation Node", "");
+  srna = RNA_def_struct(brna, "GeometryNode", "NodeInternal");
+  RNA_def_struct_ui_text(srna, "Geometry Node", "");
   RNA_def_struct_sdna(srna, "bNode");
-  RNA_def_struct_register_funcs(srna, "rna_SimulationNode_register", "rna_Node_unregister", NULL);
+  RNA_def_struct_register_funcs(srna, "rna_GeometryNode_register", "rna_Node_unregister", NULL);
 }
 
 static void rna_def_function_node(BlenderRNA *brna)
@@ -9623,7 +9851,7 @@ static void rna_def_nodetree(BlenderRNA *brna)
       {NTREE_SHADER, "SHADER", ICON_MATERIAL, "Shader", "Shader nodes"},
       {NTREE_TEXTURE, "TEXTURE", ICON_TEXTURE, "Texture", "Texture nodes"},
       {NTREE_COMPOSIT, "COMPOSITING", ICON_RENDERLAYERS, "Compositing", "Compositing nodes"},
-      {NTREE_SIMULATION, "SIMULATION", ICON_PHYSICS, "Simulation", "Simulation nodes"},
+      {NTREE_GEOMETRY, "GEOMETRY", ICON_MESH_DATA, "Geometry", "Geometry nodes"},
       {0, NULL, 0, NULL, NULL},
   };
 
@@ -9847,15 +10075,15 @@ static void rna_def_texture_nodetree(BlenderRNA *brna)
   RNA_def_struct_ui_icon(srna, ICON_TEXTURE);
 }
 
-static void rna_def_simulation_nodetree(BlenderRNA *brna)
+static void rna_def_geometry_nodetree(BlenderRNA *brna)
 {
   StructRNA *srna;
 
-  srna = RNA_def_struct(brna, "SimulationNodeTree", "NodeTree");
+  srna = RNA_def_struct(brna, "GeometryNodeTree", "NodeTree");
   RNA_def_struct_ui_text(
-      srna, "Simulation Node Tree", "Node tree consisting of linked nodes used for simulations");
+      srna, "Geometry Node Tree", "Node tree consisting of linked nodes used for geometries");
   RNA_def_struct_sdna(srna, "bNodeTree");
-  RNA_def_struct_ui_icon(srna, ICON_PHYSICS); /* TODO: Use correct icon. */
+  RNA_def_struct_ui_icon(srna, ICON_MESH_DATA); /* TODO: Use correct icon. */
 }
 
 static StructRNA *define_specific_node(BlenderRNA *brna,
@@ -9944,7 +10172,7 @@ void RNA_def_nodetree(BlenderRNA *brna)
   rna_def_shader_node(brna);
   rna_def_compositor_node(brna);
   rna_def_texture_node(brna);
-  rna_def_simulation_node(brna);
+  rna_def_geometry_node(brna);
   rna_def_function_node(brna);
 
   rna_def_nodetree(brna);
@@ -9954,7 +10182,7 @@ void RNA_def_nodetree(BlenderRNA *brna)
   rna_def_composite_nodetree(brna);
   rna_def_shader_nodetree(brna);
   rna_def_texture_nodetree(brna);
-  rna_def_simulation_nodetree(brna);
+  rna_def_geometry_nodetree(brna);
 
 #  define DefNode(Category, ID, DefFunc, EnumName, StructName, UIName, UIDesc) \
     { \
@@ -9971,13 +10199,13 @@ void RNA_def_nodetree(BlenderRNA *brna)
    */
 #  include "../../nodes/NOD_static_types.h"
 
-  /* Node group types need to be defined for shader, compositor, texture, simulation nodes
+  /* Node group types need to be defined for shader, compositor, texture, geometry nodes
    * individually. Cannot use the static types header for this, since they share the same int id.
    */
   define_specific_node(brna, "ShaderNodeGroup", "ShaderNode", "Group", "", def_group);
   define_specific_node(brna, "CompositorNodeGroup", "CompositorNode", "Group", "", def_group);
   define_specific_node(brna, "TextureNodeGroup", "TextureNode", "Group", "", def_group);
-  define_specific_node(brna, "SimulationNodeGroup", "SimulationNode", "Group", "", def_group);
+  define_specific_node(brna, "GeometryNodeGroup", "GeometryNode", "Group", "", def_group);
   def_custom_group(brna,
                    "ShaderNodeCustomGroup",
                    "ShaderNode",
diff --git a/source/blender/makesrna/intern/rna_space.c b/source/blender/makesrna/intern/rna_space.c
index e6e54abebd4..dc3e48b9c70 100644
--- a/source/blender/makesrna/intern/rna_space.c
+++ b/source/blender/makesrna/intern/rna_space.c
@@ -44,7 +44,6 @@
 #include "DNA_node_types.h"
 #include "DNA_object_types.h"
 #include "DNA_sequence_types.h"
-#include "DNA_simulation_types.h"
 #include "DNA_space_types.h"
 #include "DNA_view3d_types.h"
 #include "DNA_workspace_types.h"
@@ -2179,40 +2178,6 @@ static void rna_SpaceNodeEditor_node_tree_update(const bContext *C, PointerRNA *
   ED_node_tree_update(C);
 }
 
-#  ifdef WITH_GEOMETRY_NODES
-static PointerRNA rna_SpaceNodeEditor_simulation_get(PointerRNA *ptr)
-{
-  SpaceNode *snode = (SpaceNode *)ptr->data;
-  ID *id = snode->id;
-  if (id && GS(id->name) == ID_SIM) {
-    return rna_pointer_inherit_refine(ptr, &RNA_Simulation, snode->id);
-  }
-  else {
-    return PointerRNA_NULL;
-  }
-}
-
-static void rna_SpaceNodeEditor_simulation_set(PointerRNA *ptr,
-                                               const PointerRNA value,
-                                               struct ReportList *UNUSED(reports))
-{
-  SpaceNode *snode = (SpaceNode *)ptr->data;
-  if (!STREQ(snode->tree_idname, "SimulationNodeTree")) {
-    return;
-  }
-
-  Simulation *sim = (Simulation *)value.data;
-  if (sim != NULL) {
-    bNodeTree *ntree = sim->nodetree;
-    ED_node_tree_start(snode, ntree, NULL, NULL);
-  }
-  else {
-    ED_node_tree_start(snode, NULL, NULL, NULL);
-  }
-  snode->id = &sim->id;
-}
-#  endif
-
 static int rna_SpaceNodeEditor_tree_type_get(PointerRNA *ptr)
 {
   SpaceNode *snode = (SpaceNode *)ptr->data;
@@ -6350,19 +6315,6 @@ static void rna_def_space_node(BlenderRNA *brna)
   RNA_def_property_ui_text(
       prop, "ID From", "Data-block from which the edited data-block is linked");
 
-#  ifdef WITH_GEOMETRY_NODES
-  prop = RNA_def_property(srna, "simulation", PROP_POINTER, PROP_NONE);
-  RNA_def_property_flag(prop, PROP_EDITABLE);
-  RNA_def_property_struct_type(prop, "Simulation");
-  RNA_def_property_ui_text(prop, "Simulation", "Simulation that is being edited");
-  RNA_def_property_pointer_funcs(prop,
-                                 "rna_SpaceNodeEditor_simulation_get",
-                                 "rna_SpaceNodeEditor_simulation_set",
-                                 NULL,
-                                 NULL);
-  RNA_def_property_update(prop, NC_SPACE | ND_SPACE_NODE, NULL);
-#  endif
-
   prop = RNA_def_property(srna, "path", PROP_COLLECTION, PROP_NONE);
   RNA_def_property_collection_sdna(prop, NULL, "treepath", NULL);
   RNA_def_property_struct_type(prop, "NodeTreePath");