Bevel: add new 'Absolute' mode for interpreting 'amount' value.

This mode is like Percent, but measures absolute distance along
adjacent edges instead of a percentage.
So, for example, if you use this mode with 2 segments and profile=1,
you will see the length that the bevel moves along unbeveled edges
between beveled ones will match the value specified.
Many users seem to expect this behavior, even though it means the
bevel width is uneven, so this option is for them.

1 files changed, 18 insertions, 2 deletions

diff --git a/source/blender/bmesh/tools/bmesh_bevel.c b/source/blender/bmesh/tools/bmesh_bevel.c
index 00b647555cf..7929a686a16 100644
--- a/source/blender/bmesh/tools/bmesh_bevel.c
+++ b/source/blender/bmesh/tools/bmesh_bevel.c
@@ -5949,12 +5949,23 @@ static BevVert *bevel_vert_construct(BMesh *bm, BevelParams *bp, BMVert *v)
           z = sinf(angle_v3v3v3(v1->co, v->co, v2->co));
           e->offset_r_spec = BM_edge_calc_length(e->next->e) * bp->offset * z / 100.0f;
           break;
+        case BEVEL_AMT_ABSOLUTE:
+          /* Like Percent, but the amount gives the absolute distance along adjacent edges. */
+          v1 = BM_edge_other_vert(e->prev->e, v);
+          v2 = BM_edge_other_vert(e->e, v);
+          z = sinf(angle_v3v3v3(v1->co, v->co, v2->co));
+          e->offset_l_spec = bp->offset * z;
+          v1 = BM_edge_other_vert(e->e, v);
+          v2 = BM_edge_other_vert(e->next->e, v);
+          z = sinf(angle_v3v3v3(v1->co, v->co, v2->co));
+          e->offset_r_spec = bp->offset * z;
+          break;
         default:
           BLI_assert(!"bad bevel offset kind");
           e->offset_l_spec = bp->offset;
           break;
       }
-      if (bp->offset_type != BEVEL_AMT_PERCENT) {
+      if (bp->offset_type != BEVEL_AMT_PERCENT && bp->offset_type != BEVEL_AMT_ABSOLUTE) {
         e->offset_r_spec = e->offset_l_spec;
       }
       if (bp->use_weights) {
@@ -6000,6 +6011,10 @@ static BevVert *bevel_vert_construct(BMesh *bm, BevelParams *bp, BMVert *v)
           e->offset_l_spec = BM_edge_calc_length(e->e) * bv->offset / 100.0f;
           break;
         }
+        case BEVEL_AMT_ABSOLUTE: {
+          e->offset_l_spec = bv->offset;
+          break;
+        }
       }
       e->offset_r_spec = e->offset_l_spec;
     }
@@ -7282,7 +7297,8 @@ void BM_mesh_bevel(BMesh *bm,
     }
 
     /* Perhaps do a pass to try to even out widths. */
-    if (!bp.vertex_only && bp.offset_adjust && bp.offset_type != BEVEL_AMT_PERCENT) {
+    if (!bp.vertex_only && bp.offset_adjust && bp.offset_type != BEVEL_AMT_PERCENT &&
+        bp.offset_type != BEVEL_AMT_ABSOLUTE) {
       adjust_offsets(&bp, bm);
     }