[Bf-blender-cvs] [94866ef84f1] master: Fix Bevel intersection continuity.
Henrik Dick
noreply at git.blender.org
Sun Feb 6 22:05:07 CET 2022
Commit: 94866ef84f1907116409f8fe9c1f313405d974e8
Author: Henrik Dick
Date: Sun Feb 6 16:01:57 2022 -0500
Branches: master
https://developer.blender.org/rB94866ef84f1907116409f8fe9c1f313405d974e8
Fix Bevel intersection continuity.
This patch from Henrik Dick improves the continuity between the
grid forming corners and the edge polyons on multisegment bevels.
For details, see patch D13867.
===================================================================
M source/blender/bmesh/tools/bmesh_bevel.c
===================================================================
diff --git a/source/blender/bmesh/tools/bmesh_bevel.c b/source/blender/bmesh/tools/bmesh_bevel.c
index 2f471bf0b81..55c63a13efb 100644
--- a/source/blender/bmesh/tools/bmesh_bevel.c
+++ b/source/blender/bmesh/tools/bmesh_bevel.c
@@ -451,6 +451,16 @@ static bool nearly_parallel_normalized(const float d1[3], const float d2[3])
return compare_ff(fabsf(direction_dot), 1.0f, BEVEL_EPSILON_ANG_DOT);
}
+/**
+ * calculate the determinant of a matrix formed by three vectors
+ * \return dot(a, cross(b, c)) = determinant(a, b, c)
+ */
+static float determinant_v3v3v3(const float a[3], const float b[3], const float c[3])
+{
+ return a[0] * b[1] * c[2] + a[1] * b[2] * c[0] + a[2] * b[0] * c[1] - a[0] * b[2] * c[1] -
+ a[1] * b[0] * c[2] - a[2] * b[1] * c[0];
+}
+
/* Make a new BoundVert of the given kind, inserting it at the end of the circular linked
* list with entry point bv->boundstart, and return it. */
static BoundVert *add_new_bound_vert(MemArena *mem_arena, VMesh *vm, const float co[3])
@@ -4118,44 +4128,114 @@ static VMesh *cubic_subdiv(BevelParams *bp, VMesh *vm_in)
VMesh *vm_out = new_adj_vmesh(bp->mem_arena, n_boundary, ns_out, vm_in->boundstart);
/* First we adjust the boundary vertices of the input mesh, storing in output mesh. */
+ BoundVert *bndv = vm_in->boundstart;
for (int i = 0; i < n_boundary; i++) {
+ float co1[3], co2[3], acc[3];
+ EdgeHalf *e = bndv->elast;
+ /* Generate tangents. This is hacked together and would ideally be done elsewere and then only
+ * used here. */
+ float tangent[3], tangent2[3], normal[3];
+ bool convex = true;
+ bool orthogonal = false;
+ float stretch = 0.0f;
+ if (e) {
+ /* Projection direction is direction of the edge. */
+ sub_v3_v3v3(tangent, e->e->v1->co, e->e->v2->co);
+ if (e->is_rev) {
+ negate_v3(tangent);
+ }
+ normalize_v3(tangent);
+ if (bndv->is_arc_start || bndv->is_patch_start) {
+ BMFace *face = e->fnext;
+ if (face) {
+ copy_v3_v3(normal, face->no);
+ }
+ else {
+ zero_v3(normal);
+ }
+ madd_v3_v3v3fl(co2, bndv->profile.middle, normal, 0.1f);
+ }
+ if (bndv->is_arc_start || bp->affect_type == BEVEL_AFFECT_VERTICES) {
+ EdgeHalf *e1 = bndv->next->elast;
+ BLI_assert(e1);
+ sub_v3_v3v3(tangent2, e1->e->v1->co, e1->e->v2->co);
+ if (e1->is_rev) {
+ negate_v3(tangent2);
+ }
+ normalize_v3(tangent2);
+
+ convex = determinant_v3v3v3(tangent2, tangent, normal) < 0;
+
+ add_v3_v3(tangent2, tangent);
+ normalize_v3(tangent2);
+ copy_v3_v3(tangent, tangent2);
+ }
+ /* Calculate a factor which determines how much the interpolated mesh is
+ * going to be stretched out into the direction of the tangent.
+ * It is currently using the difference along the tangent of the
+ * central point on the profile and the current center vertex position. */
+ get_profile_point(bp, &bndv->profile, ns_in2, ns_in, co);
+ stretch = dot_v3v3(tangent, mesh_vert(vm_in, i, ns_in2, ns_in2)->co) - dot_v3v3(tangent, co);
+ stretch = fabsf(stretch);
+ /* Scale the tangent by stretch. The divide by ns_in2 comes from the Levin Paper. */
+ mul_v3_fl(tangent, stretch / ns_in2);
+ orthogonal = bndv->is_patch_start;
+ }
+ else if (bndv->prev->is_patch_start) {
+ /* If this is the second edge of a patch and therefore #e is NULL,
+ * then e->fprev has to be used/not NULL. */
+ BLI_assert(bndv->prev->elast);
+ BMFace *face = bndv->prev->elast->fnext;
+ if (face) {
+ copy_v3_v3(normal, face->no);
+ }
+ else {
+ zero_v3(normal);
+ }
+ orthogonal = true;
+ }
+ else {
+ /** Should only come here from make_cube_corner_adj_vmesh. */
+ sub_v3_v3v3(co1, mesh_vert(vm_in, i, 0, 0)->co, mesh_vert(vm_in, i, 0, 1)->co);
+ sub_v3_v3v3(co2, mesh_vert(vm_in, i, 0, 1)->co, mesh_vert(vm_in, i, 0, 2)->co);
+ cross_v3_v3v3(tangent, co1, co2);
+ /** The following constant is choosen to best match the old results. */
+ normalize_v3_length(tangent, 1.5f / ns_out);
+ }
+ /** Copy corner vertex. */
copy_v3_v3(mesh_vert(vm_out, i, 0, 0)->co, mesh_vert(vm_in, i, 0, 0)->co);
+ /** Copy the rest of the boundary vertices. */
for (int k = 1; k < ns_in; k++) {
copy_v3_v3(co, mesh_vert(vm_in, i, 0, k)->co);
- /* Smooth boundary rule. Custom profiles shouldn't be smoothed. */
- if (bp->profile_type != BEVEL_PROFILE_CUSTOM) {
- float co1[3], co2[3], acc[3];
- copy_v3_v3(co1, mesh_vert(vm_in, i, 0, k - 1)->co);
- copy_v3_v3(co2, mesh_vert(vm_in, i, 0, k + 1)->co);
-
- add_v3_v3v3(acc, co1, co2);
- madd_v3_v3fl(acc, co, -2.0f);
- madd_v3_v3fl(co, acc, -1.0f / 6.0f);
- }
+ copy_v3_v3(co1, mesh_vert(vm_in, i, 0, k - 1)->co);
+ copy_v3_v3(co2, mesh_vert(vm_in, i, 0, k + 1)->co);
+
+ add_v3_v3v3(acc, co1, co2);
+ if (bndv->is_arc_start) {
+ sub_v3_v3(co1, co);
+ sub_v3_v3(co2, co);
+ normalize_v3(co1);
+ normalize_v3(co2);
+ add_v3_v3v3(tangent, co1, co2);
+ /* This is an empirical formula to make the result look good. */
+ normalize_v3(tangent);
+ float dot = convex ? fminf(0, dot_v3v3(tangent2, tangent)) : 1.0f;
+ mul_v3_fl(tangent, stretch / ns_in * dot);
+ }
+ else if (orthogonal) {
+ sub_v3_v3(co1, co);
+ cross_v3_v3v3(tangent, normal, co1);
+ /* This is an empirical formula to make the result look good. */
+ normalize_v3_length(tangent, -bp->offset * 0.7071f / ns_in);
+ }
+ mul_v3_fl(co, 2.0f);
+ madd_v3_v3fl(co, acc, -0.25f);
+ madd_v3_v3fl(co, mesh_vert(vm_in, i, 1, k)->co, -0.5f);
+ add_v3_v3(co, tangent);
copy_v3_v3(mesh_vert_canon(vm_out, i, 0, 2 * k)->co, co);
}
- }
- /* Now adjust odd boundary vertices in output mesh, based on even ones. */
- BoundVert *bndv = vm_out->boundstart;
- for (int i = 0; i < n_boundary; i++) {
- for (int k = 1; k < ns_out; k += 2) {
- get_profile_point(bp, &bndv->profile, k, ns_out, co);
-
- /* Smooth if using a non-custom profile. */
- if (bp->profile_type != BEVEL_PROFILE_CUSTOM) {
- float co1[3], co2[3], acc[3];
- copy_v3_v3(co1, mesh_vert_canon(vm_out, i, 0, k - 1)->co);
- copy_v3_v3(co2, mesh_vert_canon(vm_out, i, 0, k + 1)->co);
-
- add_v3_v3v3(acc, co1, co2);
- madd_v3_v3fl(acc, co, -2.0f);
- madd_v3_v3fl(co, acc, -1.0f / 6.0f);
- }
-
- copy_v3_v3(mesh_vert_canon(vm_out, i, 0, k)->co, co);
- }
bndv = bndv->next;
}
vmesh_copy_equiv_verts(vm_out);
@@ -4163,7 +4243,7 @@ static VMesh *cubic_subdiv(BevelParams *bp, VMesh *vm_in)
/* Copy adjusted verts back into vm_in. */
for (int i = 0; i < n_boundary; i++) {
for (int k = 0; k < ns_in; k++) {
- copy_v3_v3(mesh_vert(vm_in, i, 0, k)->co, mesh_vert(vm_out, i, 0, 2 * k)->co);
+ copy_v3_v3(mesh_vert_canon(vm_in, i, 0, k)->co, mesh_vert_canon(vm_out, i, 0, 2 * k)->co);
}
}
@@ -4248,7 +4328,7 @@ static VMesh *cubic_subdiv(BevelParams *bp, VMesh *vm_in)
vmesh_copy_equiv_verts(vm_out);
/* The center vertex is special. */
- gamma = sabin_gamma(n_boundary);
+ gamma = sabin_gamma(n_boundary) * 0.5f;
beta = -gamma;
/* Accumulate edge verts in co1, face verts in co2. */
float co1[3], co2[3];
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