From 5e1188c44e1142cd5064de8459b8933cca5ad22a Mon Sep 17 00:00:00 2001
From: "Max Vollmer (Microsoft Havok)"
 <60260460+ms-maxvollmer@users.noreply.github.com>
Date: Fri, 26 Nov 2021 13:01:38 +0000
Subject: [PATCH] Check that positions exist before accessing them

---
 include/assimp/Vertex.h | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/include/assimp/Vertex.h b/include/assimp/Vertex.h
index ad5ff476c..f2e5572d3 100644
--- a/include/assimp/Vertex.h
+++ b/include/assimp/Vertex.h
@@ -135,7 +135,9 @@ public:
     /** Extract a particular vertex from a anim mesh and interleave all components */
     explicit Vertex(const aiAnimMesh* msh, unsigned int idx) {
         ai_assert(idx < msh->mNumVertices);
-        position = msh->mVertices[idx];
+        if (msh->HasPositions()) {
+            position = msh->mVertices[idx];
+        }
 
         if (msh->HasNormals()) {
             normal = msh->mNormals[idx];