From 6a1962b65ac6d7f0e16bf508d71215298f8cf7c5 Mon Sep 17 00:00:00 2001
From: Jan <jan@laupetin.net>
Date: Fri, 10 May 2024 22:57:22 +0200
Subject: [PATCH] chore: export separate root node for gltf

---
 src/ObjWriting/XModel/Gltf/GltfWriter.cpp | 23 +++++++++++++++++++++--
 1 file changed, 21 insertions(+), 2 deletions(-)

diff --git a/src/ObjWriting/XModel/Gltf/GltfWriter.cpp b/src/ObjWriting/XModel/Gltf/GltfWriter.cpp
index 4a63bc43..8644d852 100644
--- a/src/ObjWriting/XModel/Gltf/GltfWriter.cpp
+++ b/src/ObjWriting/XModel/Gltf/GltfWriter.cpp
@@ -37,8 +37,9 @@ namespace
             std::vector<uint8_t> bufferData;
 
             CreateJsonAsset(gltf.asset);
-            CreateMeshNode(gltf, xmodel);
             CreateSkeletonNodes(gltf, xmodel);
+            CreateMeshNode(gltf, xmodel);
+            CreateRootNode(gltf, xmodel);
             CreateMaterials(gltf, xmodel);
             CreateSkin(gltf, xmodel);
             CreateBufferViews(gltf, xmodel);
@@ -85,6 +86,23 @@ namespace
             gltf.nodes->emplace_back(std::move(meshNode));
         }
 
+        void CreateRootNode(JsonRoot& gltf, const XModelCommon& xmodel)
+        {
+            JsonNode rootNode;
+
+            if (!gltf.nodes.has_value())
+                gltf.nodes.emplace();
+
+            rootNode.children.emplace();
+            rootNode.children->push_back(m_mesh_node);
+
+            if (!xmodel.m_bones.empty())
+                rootNode.children->push_back(m_first_bone_node);
+
+            m_root_node = gltf.nodes->size();
+            gltf.nodes->emplace_back(std::move(rootNode));
+        }
+
         void CreateMesh(JsonRoot& gltf, const XModelCommon& xmodel)
         {
             if (!gltf.meshes.has_value())
@@ -250,7 +268,7 @@ namespace
             JsonScene scene;
 
             // Only add skin if the model has bones
-            scene.nodes.emplace_back(m_mesh_node);
+            scene.nodes.emplace_back(m_root_node);
 
             if (!gltf.scenes.has_value())
                 gltf.scenes.emplace();
@@ -516,6 +534,7 @@ namespace
         }
 
         unsigned m_mesh_node = 0u;
+        unsigned m_root_node = 0u;
         unsigned m_first_bone_node = 0u;
         unsigned m_position_accessor = 0u;
         unsigned m_normal_accessor = 0u;