Pose Brush: Option to disable the IK anchor point

The IK chain was using an anchor point by default as it makes sense for
posing, but for creating curved shapes it is useful to be able to
disable it.

Reviewed By: jbakker

Differential Revision: https://developer.blender.org/D6584

1 files changed, 13 insertions, 9 deletions

diff --git a/source/blender/editors/sculpt_paint/sculpt.c b/source/blender/editors/sculpt_paint/sculpt.c
index f4c94b6e5de..e0c75e1e64f 100644
--- a/source/blender/editors/sculpt_paint/sculpt.c
+++ b/source/blender/editors/sculpt_paint/sculpt.c
@@ -3576,7 +3576,9 @@ static void sculpt_flip_quat_by_symm_area(float quat[3],
   }
 }
 
-static void pose_solve_ik_chain(SculptPoseIKChain *ik_chain, const float initial_target[3])
+static void pose_solve_ik_chain(SculptPoseIKChain *ik_chain,
+                                const float initial_target[3],
+                                const bool use_anchor)
 {
   SculptPoseIKChainSegment *segments = ik_chain->segments;
   int tot_segments = ik_chain->tot_segments;
@@ -3615,13 +3617,15 @@ static void pose_solve_ik_chain(SculptPoseIKChain *ik_chain, const float initial
   }
 
   /* Move back the whole chain to preserve the anchor point. */
-  float anchor_diff[3];
-  sub_v3_v3v3(
-      anchor_diff, segments[tot_segments - 1].initial_orig, segments[tot_segments - 1].orig);
+  if (use_anchor) {
+    float anchor_diff[3];
+    sub_v3_v3v3(
+        anchor_diff, segments[tot_segments - 1].initial_orig, segments[tot_segments - 1].orig);
 
-  for (int i = 0; i < tot_segments; i++) {
-    add_v3_v3(segments[i].orig, anchor_diff);
-    add_v3_v3(segments[i].head, anchor_diff);
+    for (int i = 0; i < tot_segments; i++) {
+      add_v3_v3(segments[i].orig, anchor_diff);
+      add_v3_v3(segments[i].head, anchor_diff);
+    }
   }
 }
 
@@ -3742,8 +3746,8 @@ static void do_pose_brush(Sculpt *sd, Object *ob, PBVHNode **nodes, int totnode)
     copy_v3_v3(ik_target, ss->cache->true_location);
     add_v3_v3(ik_target, ss->cache->grab_delta);
 
-    /* Solve the IK positions */
-    pose_solve_ik_chain(ik_chain, ik_target);
+    /* Solve the IK positions. */
+    pose_solve_ik_chain(ik_chain, ik_target, brush->flag2 & BRUSH_POSE_IK_ANCHORED);
   }
 
   /* Flip the segment chain in all symmetry axis and calculate the transform matrices for each