Curves: support sculpting on deformed curves

Previously, curves sculpt tools only worked on original data. This was
very limiting, because one could effectively only sculpt the curves when
all procedural effects were turned off. This patch adds support for curves
sculpting while looking the result of procedural effects (like deformation
based on the surface mesh). This functionality is also known as "crazy space"
support in Blender.

For more details see D15407.

Differential Revision: https://developer.blender.org/D15407

1 files changed, 10 insertions, 10 deletions

diff --git a/source/blender/geometry/GEO_add_curves_on_mesh.hh b/source/blender/geometry/GEO_add_curves_on_mesh.hh
index cf60a8e8ace..68c8dc5b76b 100644
--- a/source/blender/geometry/GEO_add_curves_on_mesh.hh
+++ b/source/blender/geometry/GEO_add_curves_on_mesh.hh
@@ -13,13 +13,13 @@
 #include "DNA_mesh_types.h"
 #include "DNA_meshdata_types.h"
 
+#include "GEO_reverse_uv_sampler.hh"
+
 namespace blender::geometry {
 
 struct AddCurvesOnMeshInputs {
-  /** Information about the root points where new curves should be generated. */
-  Span<float3> root_positions_cu;
-  Span<float3> bary_coords;
-  Span<int> looptri_indices;
+  /** UV Coordinates at which the new curves should be added. */
+  Span<float2> uvs;
 
   /** Determines shape of new curves. */
   bool interpolate_length = false;
@@ -30,14 +30,10 @@ struct AddCurvesOnMeshInputs {
 
   /** Information about the surface that the new curves are attached to. */
   const Mesh *surface = nullptr;
-  BVHTreeFromMesh *surface_bvh = nullptr;
-  Span<MLoopTri> surface_looptris;
-  Span<float2> surface_uv_map;
+  const ReverseUVSampler *reverse_uv_sampler = nullptr;
   Span<float3> corner_normals_su;
 
-  /** Transformation matrices. */
-  float4x4 curves_to_surface_mat;
-  float4x4 surface_to_curves_normal_mat;
+  bke::CurvesSurfaceTransforms *transforms = nullptr;
 
   /**
    * KD-Tree that contains the root points of existing curves. This is only necessary when
@@ -51,4 +47,8 @@ struct AddCurvesOnMeshInputs {
  */
 void add_curves_on_mesh(bke::CurvesGeometry &curves, const AddCurvesOnMeshInputs &inputs);
 
+float3 compute_surface_point_normal(const MLoopTri &looptri,
+                                    const float3 &bary_coord,
+                                    const Span<float3> corner_normals);
+
 }  // namespace blender::geometry