From c15093f848e9eb295502c1891389a233d9d705c5 Mon Sep 17 00:00:00 2001
From: VaDiM <vadim.4.ivanov@gmail.com>
Date: Sat, 18 Jul 2026 01:29:08 +0300
Subject: [PATCH] Fix Live2D motion converting. Close #150

---
 .../CubismMotion3Json.cs                      | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/AssetStudioUtility/CubismLive2DExtractor/CubismMotion3Json.cs b/AssetStudioUtility/CubismLive2DExtractor/CubismMotion3Json.cs
index c08af50..f55711b 100644
--- a/AssetStudioUtility/CubismLive2DExtractor/CubismMotion3Json.cs
+++ b/AssetStudioUtility/CubismLive2DExtractor/CubismMotion3Json.cs
@@ -101,6 +101,17 @@ namespace CubismLive2DExtractor
             totalSegmentCount++;
         }
 
+        private static void FillSingleSegment(Keyframe<float> curve, SerializableCurve cubismCurve, float time, ref int totalPointCount, ref int totalSegmentCount)
+        {
+            var value = cubismCurve.Segments[1];
+            var id = float.IsPositiveInfinity(curve.inSlope) ? 2f : 0f;
+            cubismCurve.Segments.Add(id); // Segment ID
+            cubismCurve.Segments.Add(time);
+            cubismCurve.Segments.Add(value);
+            totalPointCount++;
+            totalSegmentCount++;
+        }
+
         public CubismMotion3Json(CubismUnityClasses.CubismFadeMotionData fadeMotion, HashSet<string> paramNames, HashSet<string> partNames, bool forceBezier)
         {
             Version = 3;
@@ -177,6 +188,10 @@ namespace CubismLive2DExtractor
                         fadeMotion.ParameterCurves[i].m_Curve[0].value
                     }
                 };
+                if (fadeMotion.ParameterCurves[i].m_Curve.Count == 1)
+                {
+                    FillSingleSegment(fadeMotion.ParameterCurves[i].m_Curve[0], Curves[actualCurveCount], Meta.Duration, ref totalPointCount, ref totalSegmentCount);
+                }
                 for (var j = 1; j < fadeMotion.ParameterCurves[i].m_Curve.Count; j++)
                 {
                     var curve = fadeMotion.ParameterCurves[i].m_Curve[j];
@@ -232,6 +247,10 @@ namespace CubismLive2DExtractor
                         track.Curve[0].value
                     }
                 };
+                if (track.Curve.Count == 1)
+                {
+                    FillSingleSegment(CreateKeyFrame(track.Curve[0]), Curves[i], Meta.Duration, ref totalPointCount, ref totalSegmentCount);
+                }
                 for (var j = 1; j < track.Curve.Count; j++)
                 {
                     var curve = CreateKeyFrame(track.Curve[j]);