GPv3: Vertex Weight Angle modifier

@@ -0,0 +92,4 @@
+  modifier::greasepencil::read_influence_data(reader, &mmd->influence);
+}
+
+static void deform_drawing(const ModifierData &md,

@@ -0,0 +109,4 @@
+  }
+
+  bke::MutableAttributeAccessor attributes = curves.attributes_for_write();
+  bke::SpanAttributeWriter<float> target = attributes.lookup_or_add_for_write_span<float>(mmd.target_vgname,bke::AttrDomain::Point);

@@ -0,0 +117,4 @@
+      mmd.influence.vertex_group_name, bke::AttrDomain::Point, 1.0f);
+
+  /* Use default Z up. */
+  float3 vec_axis(0.0f, 0.0f, 1.0f);

@@ -0,0 +136,4 @@
+  const Span<float3> positions = curves.positions();
+
+  strokes.foreach_index(GrainSize(512), [&](const int stroke) {
+    IndexRange points = points_by_curve[stroke];

@@ -0,0 +142,4 @@
+      return;
+    }
+    for (const int point : points.drop_front(1)) {
+      float3 p1 = math::transform_point(obmat3x3, positions[point]);

@@ -0,0 +146,4 @@
+      float3 p2 = math::transform_point(obmat3x3, positions[point - 1]);
+      float3 vec = p2 - p1;
+      const float angle = angle_on_axis_v3v3_v3(vec_ref, vec, axis);
+      float weight = target.span[point] = 1.0f - sin(angle);

@@ -119,0 +120,4 @@
+     "GREASE_PENCIL_VERTEX_WEIGHT_ANGLE",
+     ICON_MOD_VERTEX_WEIGHT,
+     "Vertex Weight Angle",
+     "Set the vertex group weights based on the angle of the stroke"},

@@ -0,0 +96,4 @@
+                                      const Object &ob,
+                                      bke::greasepencil::Drawing &drawing)
+{
+  auto &mmd = reinterpret_cast<const GPWeightAngleModifierData &>(md);

@@ -0,0 +114,4 @@
+  if (dst_weights.span.is_empty()) {
+    return;
+  }
+  const VArray<float> input_weights = *attributes.lookup_or_default<float>(

@@ -0,0 +124,4 @@
+  float3 vec_ref;
+  /* Apply modifier rotation (sub 90 degrees for Y axis due Z-Up vector). */
+  const float rot_angle = mmd.angle - ((mmd.axis == 1) ? M_PI_2 : 0.0f);
+  rotate_normalized_v3_v3v3fl(vec_ref, z_up, axis, rot_angle);

@@ -0,0 +159,4 @@
+      dst_weights.span[point] = math::clamp(dst_weights.span[point], mmd.min_weight, 1.0f);
+    }
+    /* First point has the same weight as the second one. */
+    dst_weights.span[0] = dst_weights.span[1];

@@ -0,0 +169,4 @@
+                                const ModifierEvalContext *ctx,
+                                bke::GeometrySet *geometry_set)
+{
+  GPWeightAngleModifierData *mmd = reinterpret_cast<GPWeightAngleModifierData *>(md);

@@ -0,0 +109,4 @@
+  }
+
+  bke::MutableAttributeAccessor attributes = curves.attributes_for_write();
+  bke::SpanAttributeWriter<float> dst_weights = attributes.lookup_or_add_for_write_span<float>(

@@ -0,0 +93,4 @@
+  modifier::greasepencil::read_influence_data(reader, &mmd->influence);
+}
+
+static int ensure_vertex_group(const StringRef name, ListBase &vertex_group_names)

@@ -0,0 +29,4 @@
+#include "UI_interface.hh"
+#include "UI_resources.hh"
+
+#include "GEO_smooth_curves.hh"

@@ -0,0 +99,4 @@
+      &vertex_group_names, name.c_str(), offsetof(bDeformGroup, name));
+  if (def_nr < 0) {
+    bDeformGroup *defgroup = MEM_cnew<bDeformGroup>(__func__);
+    STRNCPY(defgroup->name, name.data());

@@ -0,0 +134,4 @@
+  }
+
+  /* Make sure that the target vertex group is added to this drawing so we can write to it. */
+  ensure_vertex_group(mmd.target_vgname, drawing.strokes_for_write().vertex_group_names);

@@ -0,0 +154,4 @@
+  const float rot_angle = mmd.angle - ((mmd.axis == 1) ? M_PI_2 : 0.0f);
+  rotate_normalized_v3_v3v3fl(vec_ref, z_up, axis, rot_angle);
+
+  const float3x3 obmat3x3(float4x4(ob.object_to_world()));

@@ -0,0 +93,4 @@
+  modifier::greasepencil::read_influence_data(reader, &mmd->influence);
+}
+
+static int ensure_vertex_group(const StringRefNull name, ListBase &vertex_group_names)

@@ -8650,6 +8658,7 @@ static void rna_def_modifier_grease_pencil_thickness(BlenderRNA *brna)
 }
 
 static void rna_def_modifier_grease_pencil_lattice(BlenderRNA *brna)
+

@@ -0,0 +264,4 @@
+
+}  // namespace blender
+
+ModifierTypeInfo modifierType_GPWeightAngle = {