From 2b1e5e4958e725c36a7c5df3d399a417913f5e8e Mon Sep 17 00:00:00 2001
From: Wojciech Figat <wojtek@figat.pl>
Date: Thu, 9 Dec 2021 17:09:31 +0100
Subject: [PATCH] Fix various issues with Multi Blend 2D node

---
 Source/Engine/Animations/Graph/AnimGraph.Base.cpp    | 12 ++++++++++++
 .../Engine/Animations/Graph/AnimGroup.Animation.cpp  |  6 ++----
 2 files changed, 14 insertions(+), 4 deletions(-)

diff --git a/Source/Engine/Animations/Graph/AnimGraph.Base.cpp b/Source/Engine/Animations/Graph/AnimGraph.Base.cpp
index 8748e99bb..facf78b43 100644
--- a/Source/Engine/Animations/Graph/AnimGraph.Base.cpp
+++ b/Source/Engine/Animations/Graph/AnimGraph.Base.cpp
@@ -204,6 +204,18 @@ bool AnimGraphBase::onNodeLoaded(Node* n)
             // Triangulate
             Array<Delaunay2D::Triangle, FixedAllocation<ANIM_GRAPH_MULTI_BLEND_2D_MAX_TRIS>> triangles;
             Delaunay2D::Triangulate(vertices, triangles);
+            if (triangles.Count() == 0)
+            {
+                switch (vertices.Count())
+                {
+                case 1:
+                    triangles.Add(Delaunay2D::Triangle(0, 0, 0));
+                    break;
+                case 2:
+                    triangles.Add(Delaunay2D::Triangle(0, 1, 0));
+                    break;
+                }
+            }
 
             // Store triangles vertices indices (map the back to the anim node slots)
             for (int32 i = 0; i < triangles.Count(); i++)
diff --git a/Source/Engine/Animations/Graph/AnimGroup.Animation.cpp b/Source/Engine/Animations/Graph/AnimGroup.Animation.cpp
index 2895f7931..4b99e2026 100644
--- a/Source/Engine/Animations/Graph/AnimGroup.Animation.cpp
+++ b/Source/Engine/Animations/Graph/AnimGroup.Animation.cpp
@@ -1065,6 +1065,7 @@ void AnimGraphExecutor::ProcessGroupAnimation(Box* boxBase, Node* nodeBase, Valu
     case 13:
     {
         ASSERT(box->ID == 0);
+        value = Value::Null;
 
         // Note data layout:
         // [0]: Vector4 Range (minX, maxX, minY, maxY)
@@ -1087,7 +1088,6 @@ void AnimGraphExecutor::ProcessGroupAnimation(Box* boxBase, Node* nodeBase, Valu
         if (data.TrianglesP0[0] == ANIM_GRAPH_MULTI_BLEND_MAX_ANIMS)
         {
             // Nothing to sample
-            value = Value::Null;
             break;
         }
 
@@ -1107,7 +1107,6 @@ void AnimGraphExecutor::ProcessGroupAnimation(Box* boxBase, Node* nodeBase, Valu
         if (data.Length <= ZeroTolerance)
         {
             // Nothing to sample
-            value = Value::Null;
             break;
         }
 
@@ -1122,7 +1121,6 @@ void AnimGraphExecutor::ProcessGroupAnimation(Box* boxBase, Node* nodeBase, Valu
         ANIM_GRAPH_PROFILE_EVENT("Multi Blend 2D");
 
         // Find 3 animations to blend (triangle)
-        value = Value::Null;
         Vector2 p(x, y);
         bool hasBest = false;
         Vector2 bestPoint;
@@ -1230,7 +1228,7 @@ void AnimGraphExecutor::ProcessGroupAnimation(Box* boxBase, Node* nodeBase, Valu
         }
 
         // Check if use the closes sample
-        if (value.AsPointer == nullptr && hasBest)
+        if ((void*)value == nullptr && hasBest)
         {
             const auto aAnim = node->Assets[bestAnims[0]].As<Animation>();
             const auto aData = node->Values[4 + bestAnims[0] * 2].AsVector4();