Added support for importing GLTF models

LICENSE

@@ -36,4 +36,5 @@ fmtlib Library - see the LICENSE file in the libs/libfmt folder (BSD 2-clause "S
 OpenFBX library - see the LICENSE file in radiantcore/model/import/openfbx (MIT license)
 pugixml library - see the LICENSE file in the libs/pugixml folder (MIT license)
 SHA256 implementation - by Brad Conte, released into the public domain, see this URL: 
-    (https://github.com/B-Con/crypto-algorithms/tree/master#readme)
+    (https://github.com/B-Con/crypto-algorithms/tree/master#readme)
+cgltf library - see the LICENSE file in the radiantcore/model/import/gltf folder (MIT license)

radiantcore/model/ModelFormatManager.cpp

@@ -9,12 +9,15 @@
 
 #include "module/StaticModule.h"
 
+#include "import/GltfModelLoader.h"
 #include "import/FbxModelLoader.h"
 #include "export/AseExporter.h"
 #include "export/Lwo2Exporter.h"
 #include "export/WavefrontExporter.h"
 #include "command/ExecutionFailure.h"
 
+
+
 namespace model
 {
 
@@ -40,6 +43,7 @@ void ModelFormatManager::initialiseModule(const IApplicationContext& ctx)
 
     // Register the built-in model importers
     registerImporter(std::make_shared<FbxModelLoader>());
+    registerImporter(std::make_shared<GltfModelLoader>());
 
 	// Register the built-in model exporters
 	registerExporter(std::make_shared<AseExporter>());

radiantcore/model/import/GltfModelLoader.cpp

@@ -0,0 +1,271 @@
+#include "GltfModelLoader.h"
+
+#include <istream>
+//#include "AseModel.h"
+
+#include "os/path.h"
+#include "string/case_conv.h"
+#include "stream/ScopedArchiveBuffer.h"
+
+#include "../StaticModel.h"
+#include "parser/ParseException.h"
+#include "../picomodel/PicoModelLoader.h"
+
+//https://github.com/jkuhlmann/cgltf
+#define CGLTF_IMPLEMENTATION
+#include "gltf/cgltf.h"
+#include "../StaticModelSurface.h"
+
+namespace
+{
+    class ScopeGuard
+    {
+        std::function<void()> mExitFunc;
+    public:
+        ScopeGuard(std::function<void()> exitFunc)
+            :mExitFunc(exitFunc)
+        {
+
+        }
+
+        ~ScopeGuard()
+        {
+            mExitFunc();
+        }
+    };
+}
+
+namespace model
+{
+
+    GltfModelLoader::GltfModelLoader() :
+        ModelImporterBase("GLB")
+    {}
+
+    IModelPtr GltfModelLoader::loadModelFromPath(const std::string& path)
+    {
+        // Open an ArchiveFile to load
+        auto file = path_is_absolute(path.c_str()) ?
+            GlobalFileSystem().openFileInAbsolutePath(path) :
+            GlobalFileSystem().openFile(path);
+
+        std::string fileName = path_is_absolute(path.c_str()) ?
+            path : GlobalFileSystem().findFile(path) + path;
+
+        cgltf_options options = {};
+        cgltf_data* gltfData = NULL;
+        cgltf_result result = cgltf_parse_file(&options, fileName.c_str(), &gltfData);
+
+        if (result != cgltf_result_success)
+        {
+            //Failed to load
+            rError() << "Failed to parse GLB file " << path << std::endl;
+            return IModelPtr();
+        }
+
+        ScopeGuard freeCGLTF([gltfData] {
+            cgltf_free(gltfData);
+        });
+
+        result = cgltf_load_buffers(&options, gltfData, fileName.c_str());
+
+        if (result != cgltf_result_success)
+        {
+            //Failed to load
+            rError() << "Failed to parse GLTF buffers " << path << std::endl;
+            return IModelPtr();
+        }      
+
+        //Note: "mesh" = how many individual blender objects there are.
+        //so if the model consists of 3 objects, then: you have 3 meshes.
+
+        if (gltfData->meshes_count == 0)
+        {
+            //No mesh
+            rError() << "GLB file has no meshes " << path << std::endl;
+            return IModelPtr();
+        }
+
+        // Maps to help with hierarchy
+        std::unordered_map<cgltf_mesh*, cgltf_node*> meshToNodeMap;
+
+        for (size_t i = 0; i < gltfData->nodes_count; i++)
+        {
+            cgltf_node* node = &gltfData->nodes[i];
+            if (node->mesh)
+            {
+                meshToNodeMap.emplace(node->mesh, node);
+            }
+        }
+
+        std::vector<StaticModelSurfacePtr> staticSurfaces;
+
+        for (size_t i = 0; i < gltfData->meshes_count; i++)
+        {
+            cgltf_mesh* mesh = &gltfData->meshes[i];
+            if (mesh->primitives_count <= 0)
+            {
+                continue;
+            }
+
+            // Handle transformation of the mesh in the node, including parents
+            cgltf_node* node = meshToNodeMap[mesh];
+            float mtx[16];
+            cgltf_node_transform_world(node, mtx);
+            auto transform = Matrix4::byColumns(mtx[0], mtx[1], mtx[2], mtx[3],
+                mtx[4], mtx[5], mtx[6], mtx[7],
+                mtx[8], mtx[9], mtx[10], mtx[11],
+                mtx[12], mtx[13], mtx[14], mtx[15]);
+
+            for (size_t j = 0; j < mesh->primitives_count; j++)
+            {
+                auto& primitive = mesh->primitives[j];
+                size_t numVerts = 0;
+                size_t numIndices = 0;
+                const uint8_t* positions = nullptr;
+                const uint8_t* normals = nullptr;
+                const uint8_t* texcoords = nullptr;
+
+                for (size_t k = 0; k < primitive.attributes_count; k++)
+                {
+                    cgltf_attribute& attribute = primitive.attributes[k];
+                    std::string attributeName = attribute.name;
+                    if (attributeName == "POSITION")
+                    {
+                        cgltf_accessor* accessor = attribute.data;
+                        if (accessor->component_type != cgltf_component_type_r_32f)
+                        {
+                            rError() << "GLB file has a position attribute that doesn't use floats " << path << std::endl;
+                            return IModelPtr();
+                        }
+                        if (accessor->type != cgltf_type_vec3)
+                        {
+                            rError() << "GLB file has a position attribute that isn't a Vec3 " << path << std::endl;
+                            return IModelPtr();
+                        }
+
+                        numVerts = accessor->count;
+                        positions = reinterpret_cast<const uint8_t*>(cgltf_buffer_view_data(accessor->buffer_view));
+
+                    }
+                    else if (attributeName == "NORMAL")
+                    {
+                        cgltf_accessor* accessor = attribute.data;
+                        if (accessor->component_type != cgltf_component_type_r_32f)
+                        {
+                            rError() << "GLB file has a normal attribute that doesn't use floats " << path << std::endl;
+                            return IModelPtr();
+                        }
+                        if (accessor->type != cgltf_type_vec3)
+                        {
+                            rError() << "GLB file has a normal attribute that isn't a Vec3 " << path << std::endl;
+                            return IModelPtr();
+                        }
+
+                        normals = reinterpret_cast<const uint8_t*>(cgltf_buffer_view_data(accessor->buffer_view));
+                    }
+                    else if (attributeName == "TEXCOORD_0")
+                    {
+                        cgltf_accessor* accessor = attribute.data;
+                        if (accessor->component_type != cgltf_component_type_r_32f)
+                        {
+                            rError() << "GLB file has a texcoord_0 attribute that doesn't use floats " << path << std::endl;
+                            return IModelPtr();
+                        }
+                        if (accessor->type != cgltf_type_vec2)
+                        {
+                            rError() << "GLB file has a texcoord_0 attribute that isn't a Vec2 " << path << std::endl;
+                            return IModelPtr();
+                        }
+
+                        texcoords = reinterpret_cast<const uint8_t*>(cgltf_buffer_view_data(accessor->buffer_view));
+                    }
+                }
+
+                if (primitive.indices)
+                {
+                    const uint8_t* indicesPtr = reinterpret_cast<const uint8_t*>(cgltf_buffer_view_data(primitive.indices->buffer_view));
+                    numIndices = primitive.indices->count;
+                    cgltf_component_type indexType = primitive.indices->component_type;
+
+                    std::vector<MeshVertex> vertices;
+                    std::vector<unsigned int> indices;
+                    indices.resize(numIndices);
+
+                    if (indexType == cgltf_component_type_r_8u)
+                    {
+                        for (size_t index = 0; index < numIndices; index++)
+                        {
+                            indices[index] = indicesPtr[index];
+                        }
+                    }
+                    else if (indexType == cgltf_component_type_r_16u)
+                    {
+                        const uint16_t* ptrAs16 = reinterpret_cast<const uint16_t*>(indicesPtr);
+                        for (size_t index = 0; index < numIndices; index++)
+                        {
+                            indices[index] = ptrAs16[index];
+                        }
+                    }
+                    else if (indexType == cgltf_component_type_r_32u)
+                    {
+                        const uint32_t* ptrAs32 = reinterpret_cast<const uint32_t*>(indicesPtr);
+                        for (size_t index = 0; index < numIndices; index++)
+                        {
+                            indices[index] = ptrAs32[index];
+                        }
+                    }
+                    else
+                    {
+                        rError() << "GLB file doesn't indices of an unsigned type " << path << std::endl;
+                        return IModelPtr();
+                    }
+
+                    // GLTF is CCW winding order, but dark radiant wants CW
+                    size_t numTris = numIndices / 3;
+                    for (size_t tri = 0; tri < numTris; tri++)
+                    {
+                        std::swap(indices[tri * 3], indices[tri * 3 + 1]);
+                    }
+
+                    vertices.reserve(numVerts);
+                    const std::array<float, 3>* posVec3 = reinterpret_cast<const std::array<float, 3>*>(positions);
+                    const std::array<float, 3>* normalsVec3 = reinterpret_cast<const std::array<float, 3>*>(normals);
+                    const std::array<float, 2>* texcoordsVec2 = reinterpret_cast<const std::array<float, 2>*>(texcoords);
+                    for (size_t vertex = 0; vertex < numVerts; vertex++)
+                    {
+                        Vector3 pos = posVec3 ? Vertex3(posVec3[vertex][0], posVec3[vertex][1], posVec3[vertex][2]) : Vertex3();
+                        Vector3 normal = normalsVec3 ? Normal3(-normalsVec3[vertex][0], -normalsVec3[vertex][1], -normalsVec3[vertex][2]) : Normal3();
+
+                        pos = transform.transformPoint(pos);
+                        normal = transform.transformDirection(normal);
+                        // NOTE: Normals are negated due to winding order swap from CCW to CW
+                        vertices.emplace_back(pos, normal,
+                            texcoordsVec2 ? TexCoord2f(texcoordsVec2[vertex][0], texcoordsVec2[vertex][1]) : TexCoord2f());
+                    }
+
+                    auto& staticSurface = staticSurfaces.emplace_back(std::make_shared<StaticModelSurface>(std::move(vertices), std::move(indices)));
+                    if (primitive.material && primitive.material->name)
+                    {
+                        staticSurface->setDefaultMaterial(primitive.material->name);
+                        staticSurface->setActiveMaterial(staticSurface->getActiveMaterial());
+                    }
+                }
+                else
+                {
+                    rError() << "GLB file doesn't seem to have indices " << path << std::endl;
+                    return IModelPtr();
+                }
+            }
+        }
+
+        auto staticModel = std::make_shared<StaticModel>(staticSurfaces);
+
+        // Set the filename
+        staticModel->setFilename(os::getFilename(fileName));
+        staticModel->setModelPath(path);
+
+        return staticModel; //Return the model.
+    }
+
+}

radiantcore/model/import/GltfModelLoader.h

@@ -0,0 +1,18 @@
+#pragma once
+
+#include "ModelImporterBase.h"
+
+namespace model
+{
+
+    class GltfModelLoader :
+        public ModelImporterBase
+    {
+    public:
+        GltfModelLoader();
+
+        // Load the given model from the path, VFS or absolute
+        IModelPtr loadModelFromPath(const std::string& name) override;
+    };
+
+} // namespace model

radiantcore/model/import/gltf/LICENSE

@@ -0,0 +1,7 @@
+Copyright (c) 2018-2021 Johannes Kuhlmann
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.