Merge pull request #752 from Laupetin/fix/relink-dumped-xmodels

fix: xmodels with more than one root bone are not linkable

src/ObjLoading/XModel/Gltf/GltfLoader.cpp

@@ -12,10 +12,10 @@
 #include <deque>
 #include <exception>
 #include <format>
-#include <iostream>
 #include <limits>
 #include <nlohmann/json.hpp>
 #include <numbers>
+#include <numeric>
 #include <string>
 
 using namespace gltf;
@@ -316,7 +316,7 @@ namespace
                     || !colorAccessor->GetFloatVec4(vertexIndex, vertex.color) || !uvAccessor->GetFloatVec2(vertexIndex, vertex.uv)
                     || !jointsAccessor->GetUnsignedVec4(vertexIndex, joints) || !weightsAccessor->GetFloatVec4(vertexIndex, weights))
                 {
-                    return false;
+                    throw GltfLoadException("Failed to load vertex data from accessors");
                 }
 
                 RhcToLhcCoordinates(vertex.coordinates);
@@ -330,7 +330,16 @@ namespace
                     if (std::abs(weights[i]) < std::numeric_limits<float>::epsilon())
                         continue;
 
-                    common.m_bone_weight_data.weights.emplace_back(joints[i], weights[i]);
+                    assert(joints[i] < m_gltf_to_common_joint_index_lookup.size());
+                    if (joints[i] >= m_gltf_to_common_joint_index_lookup.size())
+                    {
+                        throw GltfLoadException(std::format(
+                            "Vertex weight referenced joint {} (there are only {} joints in skin)", joints[i], m_gltf_to_common_joint_index_lookup.size()));
+                    }
+
+                    const auto xmodelBoneIndex = m_gltf_to_common_joint_index_lookup[joints[i]];
+
+                    common.m_bone_weight_data.weights.emplace_back(xmodelBoneIndex, weights[i]);
                     vertexWeights.weightCount++;
                 }
 
@@ -406,13 +415,12 @@ namespace
             return true;
         }
 
-        static std::optional<unsigned> GetRootNodeForSkin(const JsonRoot& jRoot, const JsonSkin& skin)
+        static std::vector<unsigned> GetRootNodesForSkin(const JsonRoot& jRoot, const JsonSkin& skin)
         {
             if (!jRoot.nodes || skin.joints.empty())
-                return std::nullopt;
+                return {};
 
             const auto jointCount = skin.joints.size();
-            auto rootCount = jointCount;
             std::vector<bool> isRoot(jointCount, true);
 
             for (const auto joint : skin.joints)
@@ -432,26 +440,23 @@ namespace
                             if (isRoot[foundChildJointIndex])
                             {
                                 isRoot[foundChildJointIndex] = false;
-                                rootCount--;
                             }
                         }
                     }
                 }
             }
 
-            if (rootCount != 1)
-                throw GltfLoadException("Skins must have exactly one common root node");
-
+            std::vector<unsigned> result;
             for (auto index = 0u; index < jointCount; index++)
             {
                 if (isRoot[index])
-                    return skin.joints[index];
+                    result.emplace_back(skin.joints[index]);
             }
 
-            return std::nullopt;
+            return std::move(result);
         }
 
-        void ApplyNodeMatrixTRS(const JsonNode& node, float (&localOffsetRhc)[3], float (&localRotationRhc)[4], float (&scaleRhc)[3])
+        void ApplyNodeMatrixTRS(const JsonNode& node, float (&localOffsetRhc)[3], float (&localRotationRhc)[4], float (&scaleRhc)[3]) const
         {
             const auto matrix = Eigen::Matrix4f({
                 {(*node.matrix)[0], (*node.matrix)[4], (*node.matrix)[8],  (*node.matrix)[12]},
@@ -492,7 +497,7 @@ namespace
             scaleRhc[2] = matrix.block<3, 1>(0, 2).norm();
         }
 
-        void ApplyNodeSeparateTRS(const JsonNode& node, float (&localOffsetRhc)[3], float (&localRotationRhc)[4], float (&scaleRhc)[3])
+        void ApplyNodeSeparateTRS(const JsonNode& node, float (&localOffsetRhc)[3], float (&localRotationRhc)[4], float (&scaleRhc)[3]) const
         {
             if (node.translation)
             {
@@ -612,13 +617,63 @@ namespace
                 {
                     if (!ConvertJoint(
                             jRoot, skin, common, skinBoneOffset, childIndex, commonBoneOffset, globalTranslationEigenRhc, globalRotationEigenRhc, bone.scale))
+                    {
                         return false;
+                    }
                 }
             }
 
             return true;
         }
 
+        void ReorderBonesForXModels(XModelCommon& common)
+        {
+            const auto boneCount = common.m_bones.size();
+            m_gltf_to_common_joint_index_lookup.resize(boneCount);
+            auto reorderedBoneIndex = 0u;
+
+            std::deque<unsigned> parentIndicesToTraverse;
+            for (auto boneIndex = 0u; boneIndex < boneCount; ++boneIndex)
+            {
+                const auto& bone = common.m_bones[boneIndex];
+                if (!bone.parentIndex.has_value())
+                {
+                    parentIndicesToTraverse.emplace_back(boneIndex);
+                    m_gltf_to_common_joint_index_lookup[boneIndex] = reorderedBoneIndex++;
+                }
+            }
+
+            while (!parentIndicesToTraverse.empty())
+            {
+                const auto parentIndex = parentIndicesToTraverse.front();
+                parentIndicesToTraverse.pop_front();
+
+                for (auto boneIndex = 0u; boneIndex < boneCount; ++boneIndex)
+                {
+                    const auto& bone = common.m_bones[boneIndex];
+                    if (bone.parentIndex.has_value() && *bone.parentIndex == parentIndex)
+                    {
+                        parentIndicesToTraverse.emplace_back(boneIndex);
+                        m_gltf_to_common_joint_index_lookup[boneIndex] = reorderedBoneIndex++;
+                    }
+                }
+            }
+
+            assert(reorderedBoneIndex == boneCount);
+
+            std::vector<XModelBone> reorderedBones(boneCount);
+            for (size_t boneIndex = 0; boneIndex < boneCount; ++boneIndex)
+            {
+                auto& reorderedBone = reorderedBones[m_gltf_to_common_joint_index_lookup[boneIndex]];
+                reorderedBone = std::move(common.m_bones[boneIndex]);
+
+                if (reorderedBone.parentIndex.has_value())
+                    reorderedBone.parentIndex = m_gltf_to_common_joint_index_lookup[*reorderedBone.parentIndex];
+            }
+
+            common.m_bones = std::move(reorderedBones);
+        }
+
         bool ConvertSkin(const JsonRoot& jRoot, const JsonSkin& skin, XModelCommon& common)
         {
             if (skin.joints.empty())
@@ -626,18 +681,27 @@ namespace
             if (!jRoot.nodes)
                 return false;
 
-            const auto rootNode = GetRootNodeForSkin(jRoot, skin).value_or(skin.joints[0]);
-            const auto skinBoneOffset = static_cast<unsigned>(common.m_bones.size());
-            common.m_bones.resize(skinBoneOffset + skin.joints.size());
+            auto rootNodes = GetRootNodesForSkin(jRoot, skin);
+            if (rootNodes.empty())
+                rootNodes.emplace_back(skin.joints[0]);
 
-            const Eigen::Vector3f defaultTranslation(0.0f, 0.0f, 0.0f);
+            // Only one skin per GLTF allowed, more would require more complex mapping and reordering
+            assert(common.m_bones.empty());
+            common.m_bones.resize(skin.joints.size());
+
+            constexpr Eigen::Vector3f defaultTranslation(0.0f, 0.0f, 0.0f);
             const Eigen::Quaternionf defaultRotation(1.0f, 0.0f, 0.0f, 0.0f);
             constexpr float defaultScale[3]{1.0f, 1.0f, 1.0f};
 
-            if (!ConvertJoint(jRoot, skin, common, skinBoneOffset, rootNode, std::nullopt, defaultTranslation, defaultRotation, defaultScale))
-                return false;
+            for (const auto rootNode : rootNodes)
+            {
+                if (!ConvertJoint(jRoot, skin, common, 0, rootNode, std::nullopt, defaultTranslation, defaultRotation, defaultScale))
+                    return false;
+            }
 
+            ReorderBonesForXModels(common);
             common.CalculateBoneLocalsFromGlobals();
+
             return true;
         }
 
@@ -832,7 +896,15 @@ namespace
         std::vector<std::unique_ptr<BufferView>> m_buffer_views;
         std::vector<std::unique_ptr<Buffer>> m_buffers;
 
+        // Old gltf support for OAT used bad formulas to calculate right-handed coordinate system rotations
+        // To make the fixed code be backwards compatible, old behaviour can be restored with this setting.
         bool m_bad_rotation_formulas;
+
+        // We may need to reorder bones to account for the constraints of xmodels:
+        // Root bones have the lowest indices and the index of the parent of each bone must be lower than its own.
+        // The index in this vector is the joint index of the gltf.
+        // The value is the index in the common xmodel.
+        std::vector<unsigned> m_gltf_to_common_joint_index_lookup;
     };
 } // namespace
 

src/ObjLoading/XModel/LoaderXModel.cpp.template

@@ -323,8 +323,12 @@ namespace
             {
                 xmodel.parentList = m_memory.Alloc<unsigned char>(xmodel.numBones - xmodel.numRootBones);
 
-                // For some reason Treyarch games allocate for a vec4 here. it is treated as a vec3 though?
+#if defined(FEATURE_IW3) || defined(FEATURE_T5) || defined(FEATURE_T6)
+                // For some reason some games allocate for a vec4 here. it is treated as a vec3 though?
                 xmodel.trans = m_memory.Alloc<float>((xmodel.numBones - xmodel.numRootBones) * 4u);
+#else
+                xmodel.trans = m_memory.Alloc<float>((xmodel.numBones - xmodel.numRootBones) * 3u);
+#endif
                 xmodel.quats = m_memory.Alloc<XModelQuat>(xmodel.numBones - xmodel.numRootBones);
             }
             else
@@ -373,7 +377,11 @@ namespace
             // Viewhands seem to have nulled trans for some reason?
             if (jXModel.type.value_or(JsonXModelType::RIGID) == JsonXModelType::VIEWHANDS)
             {
+#if defined(FEATURE_IW3) || defined(FEATURE_T5) || defined(FEATURE_T6)
                 memset(xmodel.trans, 0, sizeof(float) * 4 * (xmodel.numBones - xmodel.numRootBones));
+#else
+                memset(xmodel.trans, 0, sizeof(float) * 3 * (xmodel.numBones - xmodel.numRootBones));
+#endif
             }
 
             return true;

src/ObjWriting/XModel/Gltf/GltfWriter.cpp

@@ -187,10 +187,10 @@ namespace
 
             const auto meshCount = xmodel.m_objects.size();
             for (auto meshIndex = 0u; meshIndex < meshCount; meshIndex++)
-                rootNode.children->push_back(m_first_mesh_node + meshIndex);
+                rootNode.children->emplace_back(m_first_mesh_node + meshIndex);
 
-            if (!xmodel.m_bones.empty())
-                rootNode.children->push_back(m_first_bone_node);
+            for (auto rootBoneIndex = 0u; rootBoneIndex < m_root_bone_count; rootBoneIndex++)
+                rootNode.children->emplace_back(m_first_bone_node + rootBoneIndex);
 
             m_root_node = static_cast<unsigned>(gltf.nodes->size());
             gltf.nodes->emplace_back(std::move(rootNode));
@@ -303,6 +303,7 @@ namespace
 
             const auto boneCount = common.m_bones.size();
             m_first_bone_node = static_cast<unsigned>(gltf.nodes->size());
+            m_root_bone_count = 0;
             for (auto boneIndex = 0u; boneIndex < boneCount; boneIndex++)
             {
                 JsonNode boneNode;
@@ -335,6 +336,11 @@ namespace
                     translation = inverseParentRotation * translation;
                     rotation = inverseParentRotation * rotation;
                 }
+                else
+                {
+                    assert(m_root_bone_count == boneIndex);
+                    m_root_bone_count++;
+                }
                 rotation.normalize();
 
                 boneNode.name = bone.name;
@@ -745,6 +751,7 @@ namespace
         unsigned m_first_mesh_node = 0u;
         unsigned m_root_node = 0u;
         unsigned m_first_bone_node = 0u;
+        unsigned m_root_bone_count = 0u;
         unsigned m_position_accessor = 0u;
         unsigned m_normal_accessor = 0u;
         unsigned m_color_accessor = 0u;