Add **Animation Slot** node for playing animations from code in Anim Graph

Source/Engine/Level/Actors/AnimatedModel.cpp

@@ -324,6 +324,89 @@ void AnimatedModel::ClearBlendShapeWeights()
     _blendShapes.Clear();
 }
 
+void AnimatedModel::PlaySlotAnimation(const StringView& slotName, Animation* anim, float speed, float blendInTime, float blendOutTime)
+{
+    CHECK(anim);
+    for (auto& slot : GraphInstance.Slots)
+    {
+        if (slot.Animation == anim && slot.Name == slotName)
+        {
+            slot.Pause = false;
+            slot.BlendInTime = blendInTime;
+            return;
+        }
+    }
+    int32 index = 0;
+    for (; index < GraphInstance.Slots.Count(); index++)
+    {
+        if (GraphInstance.Slots[index].Animation == nullptr)
+            break;
+    }
+    if (index == GraphInstance.Slots.Count())
+        GraphInstance.Slots.AddOne();
+    auto& slot = GraphInstance.Slots[index];
+    slot.Name = slotName;
+    slot.Animation = anim;
+    slot.Speed = speed;
+    slot.BlendInTime = blendInTime;
+    slot.BlendOutTime = blendOutTime;
+}
+
+void AnimatedModel::StopSlotAnimation()
+{
+    GraphInstance.Slots.Clear();
+}
+
+void AnimatedModel::StopSlotAnimation(const StringView& slotName, Animation* anim)
+{
+    for (auto& slot : GraphInstance.Slots)
+    {
+        if (slot.Animation == anim && slot.Name == slotName)
+        {
+            slot.Animation = nullptr;
+            break;
+        }
+    }
+}
+
+void AnimatedModel::PauseSlotAnimation()
+{
+    for (auto& slot : GraphInstance.Slots)
+        slot.Pause = true;
+}
+
+void AnimatedModel::PauseSlotAnimation(const StringView& slotName, Animation* anim)
+{
+    for (auto& slot : GraphInstance.Slots)
+    {
+        if (slot.Animation == anim && slot.Name == slotName)
+        {
+            slot.Pause = true;
+            break;
+        }
+    }
+}
+
+bool AnimatedModel::IsPlayingSlotAnimation()
+{
+    for (auto& slot : GraphInstance.Slots)
+    {
+        if (slot.Animation && !slot.Pause)
+            return true;
+    }
+    return false;
+}
+
+bool AnimatedModel::IsPlayingSlotAnimation(const StringView& slotName, Animation* anim)
+{
+    for (auto& slot : GraphInstance.Slots)
+    {
+        if (slot.Animation == anim && slot.Name == slotName && !slot.Pause)
+            return true;
+    }
+    return false;
+}
+
 void AnimatedModel::ApplyRootMotion(const RootMotionData& rootMotionDelta)
 {
     // Skip if no motion

Source/Engine/Level/Actors/AnimatedModel.h

@@ -303,6 +303,54 @@ public:
     /// </summary>
     API_FUNCTION() void ClearBlendShapeWeights();
 
+public:
+
+    /// <summary>
+    /// Plays the animation on the slot in Anim Graph.
+    /// </summary>
+    /// <param name="slotName">The name of the slot.</param>
+    /// <param name="anim">The animation to play.</param>
+    /// <param name="speed">The playback speed.</param>
+    /// <param name="blendInTime">The animation blending in time (in seconds). Cam be used to smooth the slot animation playback with the input pose when starting the animation.</param>
+    /// <param name="blendOutTime">The animation blending out time (in seconds). Cam be used to smooth the slot animation playback with the input pose when ending animation.</param>
+    API_FUNCTION() void PlaySlotAnimation(const StringView& slotName, Animation* anim, float speed = 1.0f, float blendInTime = 0.2f, float blendOutTime = 0.2f);
+
+    /// <summary>
+    /// Stops all the animations playback on the all slots in Anim Graph.
+    /// </summary>
+    API_FUNCTION() void StopSlotAnimation();
+
+    /// <summary>
+    /// Stops the animation playback on the slot in Anim Graph.
+    /// </summary>
+    /// <param name="slotName">The name of the slot.</param>
+    /// <param name="anim">The animation to stop.</param>
+    API_FUNCTION() void StopSlotAnimation(const StringView& slotName, Animation* anim);
+
+    /// <summary>
+    /// Pauses all the animations playback on the all slots in Anim Graph.
+    /// </summary>
+    API_FUNCTION() void PauseSlotAnimation();
+
+    /// <summary>
+    /// Pauses the animation playback on the slot in Anim Graph.
+    /// </summary>
+    /// <param name="slotName">The name of the slot.</param>
+    /// <param name="anim">The animation to pause.</param>
+    API_FUNCTION() void PauseSlotAnimation(const StringView& slotName, Animation* anim);
+
+    /// <summary>
+    /// Checks if the any animation playback is active on the any slot in Anim Graph (not paused).
+    /// </summary>
+    API_FUNCTION() bool IsPlayingSlotAnimation();
+
+    /// <summary>
+    /// Checks if the animation playback is active on the slot in Anim Graph (not paused).
+    /// </summary>
+    /// <param name="slotName">The name of the slot.</param>
+    /// <param name="anim">The animation to check.</param>
+    API_FUNCTION() bool IsPlayingSlotAnimation(const StringView& slotName, Animation* anim);
+
 private:
 
     void ApplyRootMotion(const RootMotionData& rootMotionDelta);