Merge pull request #295 from syoyo/empty-material

Empty material

README.md

@@ -3,7 +3,7 @@
 `TinyGLTF` is a header only C++11 glTF 2.0 https://github.com/KhronosGroup/glTF library.
 
 `TinyGLTF` uses Niels Lohmann's json library(https://github.com/nlohmann/json), so now it requires C++11 compiler.
-If you are looking for old, C++03 version, please use `devel-picojson` branch.
+If you are looking for old, C++03 version, please use `devel-picojson` branch(but not maintained anymore).
 
 ## Status
 
@@ -13,6 +13,10 @@ If you are looking for old, C++03 version, please use `devel-picojson` branch.
  - v2.1.0 release(Draco support)
  - v2.0.0 release(22 Aug, 2018)!
 
+### Branches
+
+* `sajson` : Use sajson to parse JSON. Parsing only but faster compile time(2x reduction compared to json.hpp and RapidJson)
+
 ## Builds
 
 [![Build Status](https://travis-ci.org/syoyo/tinygltf.svg?branch=devel)](https://travis-ci.org/syoyo/tinygltf)

tests/tester.cc

@@ -3,6 +3,9 @@
 #define STB_IMAGE_WRITE_IMPLEMENTATION
 #include "tiny_gltf.h"
 
+// Nlohmann json(include ../json.hpp)
+#include "json.hpp"
+
 #define CATCH_CONFIG_MAIN  // This tells Catch to provide a main() - only do this in one cpp file
 #include "catch.hpp"
 
@@ -412,6 +415,28 @@ TEST_CASE("image-uri-spaces", "[issue-236]") {
   REQUIRE(true == ret);
 }
 
+TEST_CASE("serialize-empty-material", "[issue-294]") {
+
+  tinygltf::Model m;
+
+  tinygltf::Material mat;
+  mat.pbrMetallicRoughness.baseColorFactor = {1.0f, 1.0f, 1.0f, 1.0f}; // default baseColorFactor
+  m.materials.push_back(mat);
+
+  std::stringstream os;
+
+  tinygltf::TinyGLTF ctx;
+  ctx.WriteGltfSceneToStream(&m, os, false, false);
+
+  // use nlohmann json
+  nlohmann::json j = nlohmann::json::parse(os.str());
+
+  REQUIRE(1 == j["materials"].size());
+  REQUIRE(j["asset"].is_null());
+  REQUIRE(j["materials"][0].is_object());
+
+}
+
 #ifndef TINYGLTF_NO_FS
 TEST_CASE("expandpath-utf-8", "[pr-226]") {
 

tiny_gltf.h

@@ -26,6 +26,7 @@
 // THE SOFTWARE.
 
 // Version:
+//  - v2.4.3 Fix null object output when when material has all default parameters.
 //  - v2.4.2 Decode percent-encoded URI.
 //  - v2.4.1 Fix some glTF object class does not have `extensions` and/or
 //  `extras` property.
@@ -7225,6 +7226,15 @@ static void SerializeGltfModel(Model *model, json &o) {
     for (unsigned int i = 0; i < model->materials.size(); ++i) {
       json material;
       SerializeGltfMaterial(model->materials[i], material);
+
+      if (JsonIsNull(material)) {
+        // Issue 294.
+        // `material` does not have any required parameters
+        // so the result may be null(unmodified) when all material parameters have default value.
+        //
+        // null is not allowed thus we create an empty JSON object.
+        JsonSetObject(material);
+      }
       JsonPushBack(materials, std::move(material));
     }
     JsonAddMember(o, "materials", std::move(materials));