Cycles: internal refactoring to make thick/ribbon curve separate primitives

Also removing the curve system manager which only stored a few curve intersection
settings. These are all changes towards making shape and subdivision settings
per-object instead of per-scene, but there is more work to do here.

Ref T73778

Depends on D8013

Maniphest Tasks: T73778

Differential Revision: https://developer.blender.org/D8014

6 files changed, 49 insertions, 26 deletions

diff --git a/intern/cycles/bvh/bvh_build.cpp b/intern/cycles/bvh/bvh_build.cpp
index 0235ac33c77..86ab7b00815 100644
--- a/intern/cycles/bvh/bvh_build.cpp
+++ b/intern/cycles/bvh/bvh_build.cpp
@@ -159,6 +159,13 @@ void BVHBuild::add_reference_curves(BoundBox &root, BoundBox &center, Hair *hair
   if (hair->has_motion_blur()) {
     curve_attr_mP = hair->attributes.find(ATTR_STD_MOTION_VERTEX_POSITION);
   }
+
+  const PrimitiveType primitive_type =
+      (curve_attr_mP != NULL) ?
+          ((hair->curve_shape == CURVE_RIBBON) ? PRIMITIVE_MOTION_CURVE_RIBBON :
+                                                 PRIMITIVE_MOTION_CURVE_THICK) :
+          ((hair->curve_shape == CURVE_RIBBON) ? PRIMITIVE_CURVE_RIBBON : PRIMITIVE_CURVE_THICK);
+
   const size_t num_curves = hair->num_curves();
   for (uint j = 0; j < num_curves; j++) {
     const Hair::Curve curve = hair->get_curve(j);
@@ -169,7 +176,7 @@ void BVHBuild::add_reference_curves(BoundBox &root, BoundBox &center, Hair *hair
         BoundBox bounds = BoundBox::empty;
         curve.bounds_grow(k, &hair->curve_keys[0], curve_radius, bounds);
         if (bounds.valid()) {
-          int packed_type = PRIMITIVE_PACK_SEGMENT(PRIMITIVE_CURVE, k);
+          int packed_type = PRIMITIVE_PACK_SEGMENT(primitive_type, k);
           references.push_back(BVHReference(bounds, j, i, packed_type));
           root.grow(bounds);
           center.grow(bounds.center2());
@@ -190,7 +197,7 @@ void BVHBuild::add_reference_curves(BoundBox &root, BoundBox &center, Hair *hair
           curve.bounds_grow(k, key_steps + step * num_keys, curve_radius, bounds);
         }
         if (bounds.valid()) {
-          int packed_type = PRIMITIVE_PACK_SEGMENT(PRIMITIVE_MOTION_CURVE, k);
+          int packed_type = PRIMITIVE_PACK_SEGMENT(primitive_type, k);
           references.push_back(BVHReference(bounds, j, i, packed_type));
           root.grow(bounds);
           center.grow(bounds.center2());
@@ -246,7 +253,7 @@ void BVHBuild::add_reference_curves(BoundBox &root, BoundBox &center, Hair *hair
           bounds.grow(curr_bounds);
           if (bounds.valid()) {
             const float prev_time = (float)(bvh_step - 1) * num_bvh_steps_inv_1;
-            int packed_type = PRIMITIVE_PACK_SEGMENT(PRIMITIVE_MOTION_CURVE, k);
+            int packed_type = PRIMITIVE_PACK_SEGMENT(primitive_type, k);
             references.push_back(BVHReference(bounds, j, i, packed_type, prev_time, curr_time));
             root.grow(bounds);
             center.grow(bounds.center2());
@@ -537,14 +544,22 @@ bool BVHBuild::range_within_max_leaf_size(const BVHRange &range,
   for (int i = 0; i < size; i++) {
     const BVHReference &ref = references[range.start() + i];
 
-    if (ref.prim_type() & PRIMITIVE_CURVE)
-      num_curves++;
-    if (ref.prim_type() & PRIMITIVE_MOTION_CURVE)
-      num_motion_curves++;
-    else if (ref.prim_type() & PRIMITIVE_TRIANGLE)
-      num_triangles++;
-    else if (ref.prim_type() & PRIMITIVE_MOTION_TRIANGLE)
-      num_motion_triangles++;
+    if (ref.prim_type() & PRIMITIVE_ALL_CURVE) {
+      if (ref.prim_type() & PRIMITIVE_ALL_MOTION) {
+        num_motion_curves++;
+      }
+      else {
+        num_curves++;
+      }
+    }
+    else if (ref.prim_type() & PRIMITIVE_ALL_TRIANGLE) {
+      if (ref.prim_type() & PRIMITIVE_ALL_MOTION) {
+        num_motion_triangles++;
+      }
+      else {
+        num_triangles++;
+      }
+    }
   }
 
   return (num_triangles <= params.max_triangle_leaf_size) &&
diff --git a/intern/cycles/bvh/bvh_embree.cpp b/intern/cycles/bvh/bvh_embree.cpp
index eb103b4e712..17e1f86a589 100644
--- a/intern/cycles/bvh/bvh_embree.cpp
+++ b/intern/cycles/bvh/bvh_embree.cpp
@@ -324,7 +324,6 @@ BVHEmbree::BVHEmbree(const BVHParams &params_,
       stats(NULL),
       curve_subdivisions(params.curve_subdivisions),
       build_quality(RTC_BUILD_QUALITY_REFIT),
-      use_ribbons(params.curve_flags & CURVE_KN_RIBBONS),
       dynamic_scene(true)
 {
   _MM_SET_FLUSH_ZERO_MODE(_MM_FLUSH_ZERO_ON);
@@ -771,6 +770,12 @@ void BVHEmbree::add_curves(const Object *ob, const Hair *hair, int i)
   }
 
   const size_t num_motion_steps = min(num_geometry_motion_steps, RTC_MAX_TIME_STEP_COUNT);
+  const PrimitiveType primitive_type =
+      (num_motion_steps > 1) ?
+          ((hair->curve_shape == CURVE_RIBBON) ? PRIMITIVE_MOTION_CURVE_RIBBON :
+                                                 PRIMITIVE_MOTION_CURVE_THICK) :
+          ((hair->curve_shape == CURVE_RIBBON) ? PRIMITIVE_CURVE_RIBBON : PRIMITIVE_CURVE_THICK);
+
   assert(num_geometry_motion_steps <= RTC_MAX_TIME_STEP_COUNT);
 
   const size_t num_curves = hair->num_curves();
@@ -791,11 +796,12 @@ void BVHEmbree::add_curves(const Object *ob, const Hair *hair, int i)
   size_t prim_tri_index_size = pack.prim_index.size();
   pack.prim_tri_index.resize(prim_tri_index_size + num_segments);
 
-  enum RTCGeometryType type = (use_ribbons ? RTC_GEOMETRY_TYPE_FLAT_CATMULL_ROM_CURVE :
-                                             RTC_GEOMETRY_TYPE_ROUND_CATMULL_ROM_CURVE);
+  enum RTCGeometryType type = (hair->curve_shape == CURVE_RIBBON ?
+                                   RTC_GEOMETRY_TYPE_FLAT_CATMULL_ROM_CURVE :
+                                   RTC_GEOMETRY_TYPE_ROUND_CATMULL_ROM_CURVE);
 
   RTCGeometry geom_id = rtcNewGeometry(rtc_shared_device, type);
-  rtcSetGeometryTessellationRate(geom_id, curve_subdivisions);
+  rtcSetGeometryTessellationRate(geom_id, curve_subdivisions + 1);
   unsigned *rtc_indices = (unsigned *)rtcSetNewGeometryBuffer(
       geom_id, RTC_BUFFER_TYPE_INDEX, 0, RTC_FORMAT_UINT, sizeof(int), num_segments);
   size_t rtc_index = 0;
@@ -807,8 +813,7 @@ void BVHEmbree::add_curves(const Object *ob, const Hair *hair, int i)
       rtc_indices[rtc_index] += j * 2;
       /* Cycles specific data. */
       pack.prim_object[prim_object_size + rtc_index] = i;
-      pack.prim_type[prim_type_size + rtc_index] = (PRIMITIVE_PACK_SEGMENT(
-          num_motion_steps > 1 ? PRIMITIVE_MOTION_CURVE : PRIMITIVE_CURVE, k));
+      pack.prim_type[prim_type_size + rtc_index] = (PRIMITIVE_PACK_SEGMENT(primitive_type, k));
       pack.prim_index[prim_index_size + rtc_index] = j;
       pack.prim_tri_index[prim_tri_index_size + rtc_index] = rtc_index;
 
@@ -822,7 +827,7 @@ void BVHEmbree::add_curves(const Object *ob, const Hair *hair, int i)
   update_curve_vertex_buffer(geom_id, hair);
 
   rtcSetGeometryUserData(geom_id, (void *)prim_offset);
-  if (use_ribbons) {
+  if (hair->curve_shape == CURVE_RIBBON) {
     rtcSetGeometryOccludedFilterFunction(geom_id, rtc_filter_occluded_func);
   }
   else {
diff --git a/intern/cycles/bvh/bvh_embree.h b/intern/cycles/bvh/bvh_embree.h
index b10a741fd59..f60a1ca0102 100644
--- a/intern/cycles/bvh/bvh_embree.h
+++ b/intern/cycles/bvh/bvh_embree.h
@@ -81,7 +81,7 @@ class BVHEmbree : public BVH {
   vector<RTCScene> delayed_delete_scenes;
   int curve_subdivisions;
   enum RTCBuildQuality build_quality;
-  bool use_ribbons, dynamic_scene;
+  bool dynamic_scene;
 };
 
 CCL_NAMESPACE_END
diff --git a/intern/cycles/bvh/bvh_optix.cpp b/intern/cycles/bvh/bvh_optix.cpp
index 04cff674938..ccb7ae08625 100644
--- a/intern/cycles/bvh/bvh_optix.cpp
+++ b/intern/cycles/bvh/bvh_optix.cpp
@@ -77,9 +77,12 @@ void BVHOptiX::pack_blas()
       // 'pack.prim_time' is only used in geom_curve_intersect.h
       // It is not needed because of OPTIX_MOTION_FLAG_[START|END]_VANISH
 
-      uint type = PRIMITIVE_CURVE;
-      if (hair->use_motion_blur && hair->attributes.find(ATTR_STD_MOTION_VERTEX_POSITION))
-        type = PRIMITIVE_MOTION_CURVE;
+      uint type = (hair->use_motion_blur &&
+                   hair->attributes.find(ATTR_STD_MOTION_VERTEX_POSITION)) ?
+                      ((hair->curve_shape == CURVE_RIBBON) ? PRIMITIVE_MOTION_CURVE_RIBBON :
+                                                             PRIMITIVE_MOTION_CURVE_THICK) :
+                      ((hair->curve_shape == CURVE_RIBBON) ? PRIMITIVE_CURVE_RIBBON :
+                                                             PRIMITIVE_CURVE_THICK);
 
       for (size_t j = 0; j < num_curves; ++j) {
         const Hair::Curve curve = hair->get_curve(j);
diff --git a/intern/cycles/bvh/bvh_params.h b/intern/cycles/bvh/bvh_params.h
index 5e2c4b63f1b..1a50742dc33 100644
--- a/intern/cycles/bvh/bvh_params.h
+++ b/intern/cycles/bvh/bvh_params.h
@@ -89,7 +89,6 @@ class BVHParams {
   int bvh_type;
 
   /* These are needed for Embree. */
-  int curve_flags;
   int curve_subdivisions;
 
   /* fixed parameters */
@@ -122,7 +121,6 @@ class BVHParams {
 
     bvh_type = 0;
 
-    curve_flags = 0;
     curve_subdivisions = 4;
   }
 
diff --git a/intern/cycles/bvh/bvh_unaligned.cpp b/intern/cycles/bvh/bvh_unaligned.cpp
index f0995f343fe..c969b361643 100644
--- a/intern/cycles/bvh/bvh_unaligned.cpp
+++ b/intern/cycles/bvh/bvh_unaligned.cpp
@@ -68,7 +68,8 @@ bool BVHUnaligned::compute_aligned_space(const BVHReference &ref, Transform *ali
   const Object *object = objects_[ref.prim_object()];
   const int packed_type = ref.prim_type();
   const int type = (packed_type & PRIMITIVE_ALL);
-  if (type & PRIMITIVE_CURVE) {
+  /* No motion blur curves here, we can't fit them to aligned boxes well. */
+  if (type & (PRIMITIVE_CURVE_RIBBON | PRIMITIVE_CURVE_THICK)) {
     const int curve_index = ref.prim_index();
     const int segment = PRIMITIVE_UNPACK_SEGMENT(packed_type);
     const Hair *hair = static_cast<const Hair *>(object->geometry);
@@ -93,7 +94,8 @@ BoundBox BVHUnaligned::compute_aligned_prim_boundbox(const BVHReference &prim,
   const Object *object = objects_[prim.prim_object()];
   const int packed_type = prim.prim_type();
   const int type = (packed_type & PRIMITIVE_ALL);
-  if (type & PRIMITIVE_CURVE) {
+  /* No motion blur curves here, we can't fit them to aligned boxes well. */
+  if (type & (PRIMITIVE_CURVE_RIBBON | PRIMITIVE_CURVE_THICK)) {
     const int curve_index = prim.prim_index();
     const int segment = PRIMITIVE_UNPACK_SEGMENT(packed_type);
     const Hair *hair = static_cast<const Hair *>(object->geometry);