From 2e7ba45a6c46a1b733011b451ffbf56744817efd Mon Sep 17 00:00:00 2001
From: danwillm <39023874+danwillm@users.noreply.github.com>
Date: Mon, 1 Jul 2024 18:25:59 +0100
Subject: [PATCH 1/2] Make inverseBindMatrices optional

---
 tiny_gltf.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tiny_gltf.h b/tiny_gltf.h
index 4a8d073..e0f99cc 100644
--- a/tiny_gltf.h
+++ b/tiny_gltf.h
@@ -5660,7 +5660,7 @@ static bool ParseSkin(Skin *skin, std::string *err, const detail::json &o,
   skin->skeleton = skeleton;
 
   int invBind = -1;
-  ParseIntegerProperty(&invBind, err, o, "inverseBindMatrices", true, "Skin");
+  ParseIntegerProperty(&invBind, err, o, "inverseBindMatrices", false, "Skin");
   skin->inverseBindMatrices = invBind;
 
   ParseExtrasAndExtensions(skin, err, o,

From 4ad8c82c9e24ae53b35e2d9d924a43154de9158e Mon Sep 17 00:00:00 2001
From: danwillm <39023874+danwillm@users.noreply.github.com>
Date: Mon, 1 Jul 2024 22:32:17 +0100
Subject: [PATCH 2/2] Add test for inverse bind matrices being optional

---
 tests/issue-492.glb | Bin 0 -> 372 bytes
 tests/tester.cc     |  18 ++++++++++++++++++
 2 files changed, 18 insertions(+)
 create mode 100644 tests/issue-492.glb

diff --git a/tests/issue-492.glb b/tests/issue-492.glb
new file mode 100644
index 0000000000000000000000000000000000000000..3a46d0c301036513bbc8693a4abd2d376dba9e13
GIT binary patch
literal 372
zcmbu5!3x4K42G*uA~~1R)>|LIg9kn6Z44}1(dulWDPBh3-OM>~;BALM$oJ>xPp;j0
zw`Ppx6=N5w{pon<!6Ld0riYhH=wko_T1Y4yLTnv^sd{K`zH5^sR;ikReL9j2Tmgp^
zv(2B)N(#xRQbLk8CmXQ)!|TFl#(Hk7ml^*=+%9mUOxU<U*UE1<K4f~0tji#I_%P1z
N(T6;=ifck;^9G#@Y_R|U

literal 0
HcmV?d00001

diff --git a/tests/tester.cc b/tests/tester.cc
index 807fb1c..6b10979 100644
--- a/tests/tester.cc
+++ b/tests/tester.cc
@@ -1182,3 +1182,21 @@ TEST_CASE("images-as-is", "[issue-487]") {
     }
   }
 }
+
+TEST_CASE("inverse-bind-matrices-optional", "[issue-492]") {
+  tinygltf::Model model;
+  tinygltf::TinyGLTF ctx;
+  std::string err;
+  std::string warn;
+
+  bool ret = ctx.LoadBinaryFromFile(&model, &err, &warn, "issue-492.glb");
+  if (!warn.empty()) {
+    std::cout << "WARN:" << warn << std::endl;
+  }
+  if (!err.empty()) {
+    std::cerr << "ERR:" << err << std::endl;
+  }
+
+  REQUIRE(true == ret);
+  REQUIRE(err.empty());
+}
\ No newline at end of file