1 files changed, 36 insertions, 9 deletions

diff --git a/linden/indra/llcharacter/llbvhloader.cpp b/linden/indra/llcharacter/llbvhloader.cpp
index cd1f492..938f47d 100644
--- a/linden/indra/llcharacter/llbvhloader.cpp
+++ b/linden/indra/llcharacter/llbvhloader.cpp
@@ -1133,6 +1133,8 @@ void LLBVHLoader::optimize()
 
                         F32 rot_threshold = ROTATION_KEYFRAME_THRESHOLD / llmax((F32)joint->mChildTreeMaxDepth * 0.33f, 1.f);
 
+                        double diff_max = 0;
+                        KeyVector::iterator ki_max = ki;
                         for (; ki != joint->mKeys.end(); ++ki)
                         {
                                 if (ki_prev == ki_last_good_pos)
@@ -1193,30 +1195,55 @@ void LLBVHLoader::optimize()
                                         F32 x_delta;
                                         F32 y_delta;
                                         F32 rot_test;
-
+                                        
+                                        // Test if the rotation has changed significantly since the very first frame.  If false
+                                        // for all frames, then we'll just throw out this joint's rotation entirely.
                                         x_delta = dist_vec(LLVector3::x_axis * first_frame_rot, LLVector3::x_axis * test_rot);
                                         y_delta = dist_vec(LLVector3::y_axis * first_frame_rot, LLVector3::y_axis * test_rot);
                                         rot_test = x_delta + y_delta;
-
                                         if (rot_test > ROTATION_MOTION_THRESHOLD)
                                         {
                                                 rot_changed = TRUE;
                                         }
-
                                         x_delta = dist_vec(LLVector3::x_axis * interp_rot, LLVector3::x_axis * test_rot);
                                         y_delta = dist_vec(LLVector3::y_axis * interp_rot, LLVector3::y_axis * test_rot);
                                         rot_test = x_delta + y_delta;
 
-                                        if (rot_test < rot_threshold)
-                                        {
-                                                ki_prev->mIgnoreRot = TRUE;
-                                                numRotFramesConsidered++;
-                                        }
-                                        else
+                                        // Draw a line between the last good keyframe and current.  Test the distance between the last frame (current-1, i.e. ki_prev)
+                                        // and the line.  If it's greater than some threshold, then it represents a significant frame and we want to include it.
+                                        if (rot_test >= rot_threshold ||
+                                                (ki+1 == joint->mKeys.end() && numRotFramesConsidered > 2))
                                         {
+                                                // Add the current test keyframe (which is technically the previous key, i.e. ki_prev).
                                                 numRotFramesConsidered = 2;
                                                 ki_last_good_rot = ki_prev;
                                                 joint->mNumRotKeys++;
+
+                                                // Add another keyframe between the last good keyframe and current, at whatever point was the most "significant" (i.e.
+                                                // had the largest deviation from the earlier tests).  Note that a more robust approach would be test all intermediate
+                                                // keyframes against the line between the last good keyframe and current, but we're settling for this other method
+                                                // because it's significantly faster.
+                                                if (diff_max > 0)
+                                                {
+                                                        if (ki_max->mIgnoreRot == TRUE)
+                                                        {
+                                                                ki_max->mIgnoreRot = FALSE;
+                                                                joint->mNumRotKeys++;
+                                                        }
+                                                        diff_max = 0;
+                                                }
+                                        }
+                                        else
+                                        {
+                                                // This keyframe isn't significant enough, throw it away.
+                                                ki_prev->mIgnoreRot = TRUE;
+                                                numRotFramesConsidered++;
+                                                // Store away the keyframe that has the largest deviation from the interpolated line, for insertion later.
+                                                if (rot_test > diff_max)
+                                                {
+                                                        diff_max = rot_test;
+                                                        ki_max = ki;
+                                                }
                                         }
                                 }