[Bf-blender-cvs] [2267c7c6b24] soc-2019-bevel-profiles: Bevel cutoff vertex mesh method: New profile height method.

[Hans Goudey]

Commit: 2267c7c6b245c926a575dbac6984f247c660994d
Author: Hans Goudey
Date:   Fri Jul 26 21:58:08 2019 -0400
Branches: soc-2019-bevel-profiles
https://developer.blender.org/rB2267c7c6b245c926a575dbac6984f247c660994d

Bevel cutoff vertex mesh method: New profile height method.

The height of the transformed profile is calculated when cutoff profiles
are enabled and then used later for the length of the sides of the cutoff
faces in the vertex mesh. The lengths can still be incorrect for more
acute angles between incoming edges, but the solution to that will probably
be related to the solution for the directions of the cutoff face sides.

===================================================================

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 da79b5ce54f..d4834407608 100644
--- a/source/blender/bmesh/tools/bmesh_bevel.c
+++ b/source/blender/bmesh/tools/bmesh_bevel.c
@@ -139,21 +139,20 @@ typedef struct EdgeHalf {
 typedef struct Profile {
   /** Superellipse r parameter */
   float super_r;
+  /** Height for profile cutoff face sides */
+  float height;
   /** Start control point for profile */
-  /* HANS-QUESTION: How much would it be possible to change variable names? I think "coa" and "cob"
-   * would be much more intuitively named as "start" and "end," but notes would be out of date */
-  float start[3]; /* coa */
+  float start[3];
   /** Mid control point for profile */
-  float middle[3]; /* midco */
+  float middle[3];
   /** End control point for profile */
-  float end[3]; /* cob */
+  float end[3];
   /** Normal of plane to project to */
   float plane_no[3];
   /** Coordinate on plane to project to */
   float plane_co[3];
   /** Direction of projection line */
   float proj_dir[3];
-  int _pad;
   /** seg+1 profile coordinates (triples of floats) */
   float *prof_co;
   /** Like prof_co, but for seg power of 2 >= seg */
@@ -1693,7 +1692,7 @@ static void calculate_profile(BevelParams *bp, BoundVert *bndv, bool reversed, b
 {
   int i, k, ns;
   const double *xvals, *yvals;
-  float co[3], co2[3], p[3], m[4][4];
+  float co[3], co2[3], p[3], map[4][4], bottom_corner[3], top_corner[3];
   float *prof_co, *prof_co_k;
   float r;
   bool need_2, map_ok;
@@ -1721,7 +1720,19 @@ static void calculate_profile(BevelParams *bp, BoundVert *bndv, bool reversed, b
     map_ok = false;
   }
   else {
-    map_ok = make_unit_square_map(pro->start, pro->middle, pro->end, m);
+    map_ok = make_unit_square_map(pro->start, pro->middle, pro->end, map);
+  }
+  if (bp->vmesh_method == BEVEL_VMESH_CUTOFF && map_ok) {
+    /* Calculate the "height" of the profile by putting the (0,0) and (1,1) corners of the
+     * un-transformed profile throught the 2D->3D map and calculating the distance between them */
+    p[0] = 0.0f;
+    p[1] = 0.0f;
+    p[2] = 0.0f;
+    mul_v3_m4v3(bottom_corner, map, p);
+    p[0] = 1.0f;
+    p[1] = 1.0f;
+    mul_v3_m4v3(top_corner, map, p);
+    pro->height = len_v3v3(bottom_corner, top_corner);
   }
   /* The first iteration is the nseg case, the second is the seg_2 case (if it's needed) */
   for (i = 0; i < 2; i++) {
@@ -1761,7 +1772,7 @@ static void calculate_profile(BevelParams *bp, BoundVert *bndv, bool reversed, b
           }
           p[2] = 0.0f;
           /* Do the 2D->3D transformation of the profile coordinates */
-          mul_v3_m4v3(co, m, p);
+          mul_v3_m4v3(co, map, p);
         }
         else {
           interp_v3_v3v3(co, pro->start, pro->end, (float)k / (float)ns);
@@ -5192,6 +5203,7 @@ static void bevel_build_cutoff(BevelParams *bp, BMesh *bm, BevVert *bv)
   int i;
   int n_bndv = bv->vmesh->count;
   BoundVert *bndv;
+  float length;
   float down_direction[3], new_vert[3];
   bool build_center_face;
   BMFace *repface;
@@ -5208,9 +5220,9 @@ static void bevel_build_cutoff(BevelParams *bp, BMesh *bm, BevVert *bv)
     /* HANS-TODO: This cross product doesn't work for all situations */
     cross_v3_v3v3(down_direction, bndv->profile.plane_no, bndv->prev->profile.plane_no);
 
-    /* Move down that direction from the boundvert by the width of the bevel */
-    /* HANS-TODO: Use the transformed profile height for this vertex */
-    madd_v3_v3v3fl(new_vert, bndv->nv.co, down_direction, bp->offset);
+    /* Move down from the boundvert by average profile height from the two adjacent profiles */
+    length = (bndv->profile.height / sqrtf(2.0f) +  bndv->prev->profile.height / sqrtf(2.0f)) / 2;
+    madd_v3_v3v3fl(new_vert, bndv->nv.co, down_direction, length);
 
     /* Use this location for this profile's first corner vert and the last profile's second */
     copy_v3_v3(mesh_vert(bv->vmesh, i, 1, 0)->co, new_vert);