Geometry Nodes: Attribute Statistic Node

This nodes evaluates a field on a geometry and outputs various
statistics about the entire data set, like min, max, or even
the standard deviation. It works for float and vector types currently,
though more types could be supported in the future.

 - All statistics are calculated element-wise for vectors.
 - "Product" was not added since the result could very easily overflow.
 - The "Size" output was not added since it isn't specific to an
   attribute and would fit better in another node.

The implementation shares work as much as possible when multiple
statistics are needed.

This node has been in development since the beginning of this year,
with additions from Johnny Matthews and Hans Goudey.

Differential Revision: https://developer.blender.org/D10202

1 files changed, 34 insertions, 0 deletions

diff --git a/source/blender/makesrna/intern/rna_nodetree.c b/source/blender/makesrna/intern/rna_nodetree.c
index 76e37dbcdbc..ae5f8d5f5da 100644
--- a/source/blender/makesrna/intern/rna_nodetree.c
+++ b/source/blender/makesrna/intern/rna_nodetree.c
@@ -2168,6 +2168,17 @@ static const EnumPropertyItem *rna_GeometryNodeAttributeFill_type_itemf(bContext
   return itemf_function_check(rna_enum_attribute_type_items, attribute_fill_type_supported);
 }
 
+static bool attribute_statistic_type_supported(const EnumPropertyItem *item)
+{
+  return ELEM(item->value, CD_PROP_FLOAT, CD_PROP_FLOAT3);
+}
+static const EnumPropertyItem *rna_GeometryNodeAttributeStatistic_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_statistic_type_supported);
+}
+
 /**
  * This bit of ugly code makes sure the float / attribute option shows up instead of
  * vector / attribute if the node uses an operation that uses a float for input B or C.
@@ -9219,6 +9230,29 @@ static void def_geo_attribute_convert(StructRNA *srna)
   RNA_def_property_update(prop, NC_NODE | NA_EDITED, "rna_Node_update");
 }
 
+static void def_geo_attribute_statistic(StructRNA *srna)
+{
+  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);
+  RNA_def_property_enum_funcs(prop, NULL, NULL, "rna_GeometryNodeAttributeStatistic_type_itemf");
+  RNA_def_property_enum_default(prop, CD_PROP_FLOAT);
+  RNA_def_property_ui_text(
+      prop,
+      "Data Type",
+      "The data type the attribute is converted to before calculating the results");
+  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);
+  RNA_def_property_enum_default(prop, ATTR_DOMAIN_POINT);
+  RNA_def_property_ui_text(prop, "Domain", "Which domain to read the data from");
+  RNA_def_property_update(prop, NC_NODE | NA_EDITED, "rna_Node_update");
+}
+
 static void def_geo_attribute_math(StructRNA *srna)
 {
   PropertyRNA *prop;