Transform: optimize vertex snap w/ nearest-to-ray

Use BLI_bvhtree_find_nearest_to_ray for vertex snapping,
avoids doing screen-space lookup on each vertex.

source/blender/blenkernel/BKE_bvhutils.h

@@ -51,6 +51,7 @@ typedef struct BVHTreeFromMesh {
 	/* default callbacks to bvh nearest and raycast */
 	BVHTree_NearestPointCallback nearest_callback;
 	BVHTree_RayCastCallback raycast_callback;
+	BVHTree_NearestToRayCallback nearest_to_ray_callback;
 
 	/* Vertex array, so that callbacks have instante access to data */
 	const struct MVert *vert;
@@ -147,6 +148,8 @@ enum {
 	BVHTREE_FROM_FACES_EDITMESH_ALL     = 4,
 	/* visible unselected, only used for transform snapping */
 	BVHTREE_FROM_FACES_EDITMESH_SNAP    = 5,
+	// BVHTREE_FROM_EDGES_EDITMESH_SNAP    = 6,
+	BVHTREE_FROM_VERTS_EDITMESH_SNAP    = 7,
 };
 
 typedef struct LinkNode *BVHCache;

source/blender/blenkernel/intern/bvhutils.c

@@ -382,17 +382,40 @@ static void mesh_edges_spherecast(void *userdata, int index, const BVHTreeRay *r
 
 static BVHTree *bvhtree_from_mesh_verts_create_tree(
         float epsilon, int tree_type, int axis,
+        BMEditMesh *em, const int *index_array,
         MVert *vert, const int numVerts,
         BLI_bitmap *mask, int numVerts_active)
 {
 	BVHTree *tree = NULL;
+	BMVert *eve = NULL;
 	int i;
-
+	int index = 0;
+	if (em != NULL) {
+		BM_mesh_elem_table_ensure(em->bm, BM_VERT);
+	}
 	if (vert) {
 		if (mask && numVerts_active < 0) {
 			numVerts_active = 0;
 			for (i = 0; i < numVerts; i++) {
 				if (BLI_BITMAP_TEST_BOOL(mask, i)) {
+					if (em != NULL) {
+						if (index_array){
+							index = index_array[i];
+							if (index == ORIGINDEX_NONE) {
+								continue;
+							}
+						}
+						else {
+							index = i;
+						}
+
+						eve = BM_vert_at_index(em->bm, index);
+						if (BM_elem_flag_test(eve, BM_ELEM_HIDDEN) ||
+						    BM_elem_flag_test(eve, BM_ELEM_SELECT))
+						{
+							continue;
+						}
+					}
 					numVerts_active++;
 				}
 			}
@@ -408,6 +431,24 @@ static BVHTree *bvhtree_from_mesh_verts_create_tree(
 				if (mask && !BLI_BITMAP_TEST_BOOL(mask, i)) {
 					continue;
 				}
+				if (em != NULL) {
+					if (index_array){
+						index = index_array[i];
+						if (index == ORIGINDEX_NONE) {
+							continue;
+						}
+					}
+					else {
+						index = i;
+					}
+
+					eve = BM_vert_at_index(em->bm, index);
+					if (BM_elem_flag_test(eve, BM_ELEM_HIDDEN) ||
+					    BM_elem_flag_test(eve, BM_ELEM_SELECT))
+					{
+						continue;
+					}
+				}
 				BLI_bvhtree_insert(tree, i, vert[i].co, 1);
 			}
 
@@ -432,6 +473,7 @@ static void bvhtree_from_mesh_verts_setup_data(
 		 * remember the min distance to point is the same as the min distance to BV of point */
 		data->nearest_callback = NULL;
 		data->raycast_callback = mesh_verts_spherecast;
+		data->nearest_to_ray_callback = NULL;
 
 		data->vert = vert;
 		data->vert_allocated = vert_allocated;
@@ -449,12 +491,14 @@ static void bvhtree_from_mesh_verts_setup_data(
 /* Builds a bvh tree where nodes are the vertices of the given dm */
 BVHTree *bvhtree_from_mesh_verts(BVHTreeFromMesh *data, DerivedMesh *dm, float epsilon, int tree_type, int axis)
 {
+	BMEditMesh *em = data->em_evil;
+	const int bvhcache_type = em ? BVHTREE_FROM_VERTS_EDITMESH_SNAP : BVHTREE_FROM_VERTS;
 	BVHTree *tree;
 	MVert *vert;
 	bool vert_allocated;
 
 	BLI_rw_mutex_lock(&cache_rwlock, THREAD_LOCK_READ);
-	tree = bvhcache_find(&dm->bvhCache, BVHTREE_FROM_VERTS);
+	tree = bvhcache_find(&dm->bvhCache, bvhcache_type);
 	BLI_rw_mutex_unlock(&cache_rwlock);
 
 	vert = DM_get_vert_array(dm, &vert_allocated);
@@ -462,13 +506,26 @@ BVHTree *bvhtree_from_mesh_verts(BVHTreeFromMesh *data, DerivedMesh *dm, float e
 	/* Not in cache */
 	if (tree == NULL) {
 		BLI_rw_mutex_lock(&cache_rwlock, THREAD_LOCK_WRITE);
-		tree = bvhcache_find(&dm->bvhCache, BVHTREE_FROM_VERTS);
+		tree = bvhcache_find(&dm->bvhCache, bvhcache_type);
 		if (tree == NULL) {
-			tree = bvhtree_from_mesh_verts_create_tree(epsilon, tree_type, axis, vert, dm->getNumVerts(dm), NULL, -1);
+			int vert_num, *index_array = NULL;
+			if (em != NULL) {
+				vert_num = em->bm->totvert;
+				index_array = dm->getVertDataArray(dm, CD_ORIGINDEX);
+			}
+			else {
+				vert_num = dm->getNumVerts(dm);
+				BLI_assert(vert_num != 0);
+			}
+			tree = bvhtree_from_mesh_verts_create_tree(
+				epsilon, tree_type, axis,
+				em, index_array,
+				vert, vert_num, NULL, -1);
+
 			if (tree) {
 				/* Save on cache for later use */
 				/* printf("BVHTree built and saved on cache\n"); */
-				bvhcache_insert(&dm->bvhCache, tree, BVHTREE_FROM_VERTS);
+				bvhcache_insert(&dm->bvhCache, tree, bvhcache_type);
 			}
 		}
 		BLI_rw_mutex_unlock(&cache_rwlock);
@@ -494,7 +551,7 @@ BVHTree *bvhtree_from_mesh_verts_ex(
         BLI_bitmap *mask, int numVerts_active,
         float epsilon, int tree_type, int axis)
 {
-	BVHTree *tree = bvhtree_from_mesh_verts_create_tree(epsilon, tree_type, axis, vert, numVerts, mask, numVerts_active);
+	BVHTree *tree = bvhtree_from_mesh_verts_create_tree(epsilon, tree_type, axis, NULL, NULL, vert, numVerts, mask, numVerts_active);
 
 	/* Setup BVHTreeFromMesh */
 	bvhtree_from_mesh_verts_setup_data(data, tree, false, epsilon, vert, vert_allocated);
@@ -568,6 +625,7 @@ BVHTree *bvhtree_from_mesh_edges(BVHTreeFromMesh *data, DerivedMesh *dm, float e
 
 		data->nearest_callback = mesh_edges_nearest_point;
 		data->raycast_callback = mesh_edges_spherecast;
+		data->nearest_to_ray_callback = NULL;
 
 		data->vert = vert;
 		data->vert_allocated = vert_allocated;
@@ -723,10 +781,12 @@ static void bvhtree_from_mesh_faces_setup_data(
 		if (em) {
 			data->nearest_callback = editmesh_faces_nearest_point;
 			data->raycast_callback = editmesh_faces_spherecast;
+			data->nearest_to_ray_callback = NULL;
 		}
 		else {
 			data->nearest_callback = mesh_faces_nearest_point;
 			data->raycast_callback = mesh_faces_spherecast;
+			data->nearest_to_ray_callback = NULL;
 
 			data->vert = vert;
 			data->vert_allocated = vert_allocated;
@@ -968,10 +1028,12 @@ static void bvhtree_from_mesh_looptri_setup_data(
 		if (em) {
 			data->nearest_callback = editmesh_faces_nearest_point;
 			data->raycast_callback = editmesh_faces_spherecast;
+			data->nearest_to_ray_callback = NULL;
 		}
 		else {
 			data->nearest_callback = mesh_looptri_nearest_point;
 			data->raycast_callback = mesh_looptri_spherecast;
+			data->nearest_to_ray_callback = NULL;
 
 			data->vert = vert;
 			data->vert_allocated = vert_allocated;

source/blender/editors/transform/transform_snap.c

@@ -1660,50 +1660,26 @@ static bool snapDerivedMesh(
 			}
 			case SCE_SNAP_MODE_VERTEX:
 			{
-				MVert *verts = dm->getVertArray(dm);
+				BVHTreeNearest nearest;
-				const int *index_array = NULL;
+				BVHTreeFromMesh treeData;
-				int index = 0;
-				int i;
 
-				if (em != NULL) {
+				treeData.em_evil = em;
-					index_array = dm->getVertDataArray(dm, CD_ORIGINDEX);
+				bvhtree_from_mesh_verts(&treeData, dm, 0.0f, 2, 6);
-					BM_mesh_elem_table_ensure(em->bm, BM_VERT);
+
-				}
+				nearest.index = -1;
-
+				nearest.dist_sq = FLT_MAX;
-				for (i = 0; i < totvert; i++) {
+				if (treeData.tree &&
-					BMVert *eve = NULL;
+				    BLI_bvhtree_find_nearest_to_ray(
-					MVert *v = verts + i;
+				        treeData.tree, ray_start_local, ray_normal_local, 0.0f,
-					bool test = true;
+				        &nearest, NULL, &treeData) != -1)
-
+				{
-					if (em != NULL) {
+					MVert v = treeData.vert[nearest.index];
-						if (index_array) {
+					retval = snapVertex(
-							index = index_array[i];
+						ar, v.co, v.no, obmat, timat, mval,
-						}
+						ray_start, ray_start_local, ray_normal_local, ray_depth,
-						else {
+						r_loc, r_no, r_dist_px);
-							index = i;
-						}
-						
-						if (index == ORIGINDEX_NONE) {
-							test = false;
-						}
-						else {
-							eve = BM_vert_at_index(em->bm, index);
-							
-							if (BM_elem_flag_test(eve, BM_ELEM_HIDDEN) ||
-							    BM_elem_flag_test(eve, BM_ELEM_SELECT))
-							{
-								test = false;
-							}
-						}
-					}
-
-					if (test) {
-						retval |= snapVertex(
-						        ar, v->co, v->no, obmat, timat, mval,
-						        ray_start, ray_start_local, ray_normal_local, ray_depth,
-						        r_loc, r_no, r_dist_px);
-					}
 				}
+				free_bvhtree_from_mesh(&treeData);
 
 				break;
 			}