Merge pull request #401 from jmousseau/animation-channel-node-optionality

Fix animation channel target node optionality

README.md

@@ -2,13 +2,13 @@
 
 `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.
+`TinyGLTF` uses Niels Lohmann's json library (https://github.com/nlohmann/json), so now it requires C++11 compiler.
 (Also, you can use RadpidJSON as an JSON backend)
-If you are looking for old, C++03 version, please use `devel-picojson` branch(but not maintained anymore).
+If you are looking for old, C++03 version, please use `devel-picojson` branch (but not maintained anymore).
 
 ## Status
 
-Currently TinyGLTF is stable and maintainance mode. No drastic changes and feature additions planned.
+Currently TinyGLTF is stable and maintenance mode. No drastic changes and feature additions planned.
 
  - v2.8.0 Add URICallbacks for custom URI handling in Buffer and Image. PR#397
  - v2.7.0 Change WriteImageDataFunction user callback function signature. PR#393

tiny_gltf.h

@@ -26,6 +26,7 @@
 // THE SOFTWARE.
 
 // Version:
+//  - v2.8.1 Missed serialization texture sampler name fixed. PR#399.
 //  - v2.8.0 Add URICallbacks for custom URI handling in Buffer and Image. PR#397.
 //  - v2.7.0 Change WriteImageDataFunction user callback function signature. PR#393.
 //  - v2.6.3 Fix GLB file with empty BIN chunk was not handled. PR#382 and PR#383.
@@ -546,9 +547,10 @@ typedef std::map<std::string, Value> ExtensionMap;
 
 struct AnimationChannel {
   int sampler;              // required
-  int target_node;          // required (index of the node to target)
-  std::string target_path;  // required in ["translation", "rotation", "scale",
-                            // "weights"]
+  int target_node;          // optional index of the node to target (alternative
+                            // target should be provided by extension)
+  std::string target_path;  // required with standard values of ["translation",
+                            // "rotation", "scale", "weights"]
   Value extras;
   ExtensionMap extensions;
   ExtensionMap target_extensions;
@@ -5102,12 +5104,7 @@ static bool ParseAnimationChannel(
   if (FindMember(o, "target", targetIt) && IsObject(GetValue(targetIt))) {
     const json &target_object = GetValue(targetIt);
 
-    if (!ParseIntegerProperty(&targetIndex, err, target_object, "node", true)) {
-      if (err) {
-        (*err) += "`node` field is missing in animation.channels.target\n";
-      }
-      return false;
-    }
+    ParseIntegerProperty(&targetIndex, err, target_object, "node", false);
 
     if (!ParseStringProperty(&channel->target_path, err, target_object, "path",
                              true)) {
@@ -6967,7 +6964,11 @@ static void SerializeGltfAnimationChannel(const AnimationChannel &channel,
   SerializeNumberProperty("sampler", channel.sampler, o);
   {
     json target;
-    SerializeNumberProperty("node", channel.target_node, target);
+
+    if (channel.target_node > 0) {
+      SerializeNumberProperty("node", channel.target_node, target);
+    }
+
     SerializeStringProperty("path", channel.target_path, target);
 
     SerializeExtensionMap(channel.target_extensions, target);
@@ -7440,6 +7441,9 @@ static void SerializeGltfNode(const Node &node, json &o) {
 }
 
 static void SerializeGltfSampler(const Sampler &sampler, json &o) {
+  if (!sampler.name.empty()) {
+    SerializeStringProperty("name", sampler.name, o);
+  }
   if (sampler.magFilter != -1) {
     SerializeNumberProperty("magFilter", sampler.magFilter, o);
   }