Geometry Nodes: Attribute Fill Node

This commit adds a node that fills every element of an attribute
with the same value. Currently it supports float, vector, and color
attributes. An immediate use case is for "billboard" scattering.

Currently people are using the same input to a Random Attribute node's
min and max input to fill every element of a vector with the same value,
which is an unintuitive way to accomplish the same thing.

Differential Revision: https://developer.blender.org/D9790

1 files changed, 31 insertions, 0 deletions

diff --git a/source/blender/makesrna/intern/rna_nodetree.c b/source/blender/makesrna/intern/rna_nodetree.c
index dd02cc214e0..07dba3e55a1 100644
--- a/source/blender/makesrna/intern/rna_nodetree.c
+++ b/source/blender/makesrna/intern/rna_nodetree.c
@@ -1879,6 +1879,30 @@ static const EnumPropertyItem *rna_GeometryNodeAttributeRandom_domain_itemf(
   return itemf_function_check(rna_enum_attribute_domain_items, attribute_random_domain_supported);
 }
 
+static bool attribute_fill_type_supported(const EnumPropertyItem *item)
+{
+  return ELEM(item->value, CD_PROP_FLOAT, CD_PROP_FLOAT3, CD_PROP_COLOR);
+}
+static const EnumPropertyItem *rna_GeometryNodeAttributeFill_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_fill_type_supported);
+}
+
+static bool attribute_fill_domain_supported(const EnumPropertyItem *item)
+{
+  return item->value == ATTR_DOMAIN_POINT;
+}
+static const EnumPropertyItem *rna_GeometryNodeAttributeFill_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_fill_domain_supported);
+}
+
 static bool attribute_math_operation_supported(const EnumPropertyItem *item)
 {
   return ELEM(item->value,
@@ -8343,6 +8367,13 @@ static void def_geo_random_attribute(StructRNA *srna)
                                   "rna_GeometryNodeAttributeRandom_domain_itemf");
 }
 
+static void def_geo_attribute_fill(StructRNA *srna)
+{
+  def_geo_attribute_create_common(srna,
+                                  "rna_GeometryNodeAttributeFill_type_itemf",
+                                  "rna_GeometryNodeAttributeFill_domain_itemf");
+}
+
 static void def_geo_attribute_math(StructRNA *srna)
 {
   PropertyRNA *prop;