From a70ef5c1d1cef841e1bb6f3b4ba09734487441e3 Mon Sep 17 00:00:00 2001
From: Michael Sundqvist <michael.sundqvist1@gmail.com>
Date: Fri, 29 Mar 2019 13:50:26 +0200
Subject: [PATCH] Add preserveUnusedSemantics option.

---
 GLTF/include/GLTFOptions.h |  1 +
 src/main.cpp               | 10 +++++++++-
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/GLTF/include/GLTFOptions.h b/GLTF/include/GLTFOptions.h
index 312e25458..1d9d28a7a 100644
--- a/GLTF/include/GLTFOptions.h
+++ b/GLTF/include/GLTFOptions.h
@@ -16,6 +16,7 @@ namespace GLTF {
 		bool doubleSided = false;
 		bool glsl = false;
 		bool specularGlossiness = false;
+		bool preserveUnusedSemantics = false;
 		std::string version = "2.0";
 		std::vector<std::string> metallicRoughnessTexturePaths;
 		// For Draco compression extension.
diff --git a/src/main.cpp b/src/main.cpp
index 5f3d28c44..ea5600d24 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -76,6 +76,11 @@ int main(int argc, const char **argv) {
 		->alias("version")
 		->description("glTF version to output (e.g. '1.0', '2.0')");
 
+	parser->define("p", &options->preserveUnusedSemantics)
+			->alias("preserveUnusedSemantics")
+			->defaults(false)
+			->description("should unused semantics be preserved. When this value is true, all mesh data is left intact even if it's not used.");
+
 	parser->define("metallicRoughnessTextures", &options->metallicRoughnessTexturePaths)
 		->description("paths to images to use as the PBR metallicRoughness textures");
 
@@ -192,7 +197,10 @@ int main(int argc, const char **argv) {
 
 		asset->mergeAnimations(writer->getAnimationGroups());
 		asset->removeUnusedNodes(options);
-		asset->removeUnusedSemantics();
+
+		if (!options->preserveUnusedSemantics) {
+			asset->removeUnusedSemantics();
+		}
 
 		if (options->dracoCompression) {
 			asset->removeUncompressedBufferViews();