From 3daf2b712a257a686f49486c7981ec3bd30116e3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E2=80=9CBrandon?= <contact@brandonbarker.me>
Date: Tue, 9 Jul 2019 11:41:53 -0400
Subject: [PATCH] Fix issue where code segfaults when surface material is
 missing

Ignores missing material and warns user of bad FBX

Only edge case is handled while previously working models should operate as before
---
 src/fbx/materials/FbxMaterials.cpp | 17 +++++++++++++++--
 1 file changed, 15 insertions(+), 2 deletions(-)

diff --git a/src/fbx/materials/FbxMaterials.cpp b/src/fbx/materials/FbxMaterials.cpp
index 7aeebcc..f553193 100644
--- a/src/fbx/materials/FbxMaterials.cpp
+++ b/src/fbx/materials/FbxMaterials.cpp
@@ -12,6 +12,8 @@
 #include "RoughnessMetallicMaterials.hpp"
 #include "TraditionalMaterials.hpp"
 
+static int warnMtrCount = 0;
+
 FbxMaterialsAccess::FbxMaterialsAccess(
     const FbxMesh* pMesh,
     const std::map<const FbxTexture*, FbxString>& textureLocations)
@@ -43,9 +45,16 @@ FbxMaterialsAccess::FbxMaterialsAccess(
       continue;
     }
 
-    FbxSurfaceMaterial* surfaceMaterial =
+    auto* surfaceMaterial =
         mesh->GetNode()->GetSrcObject<FbxSurfaceMaterial>(materialNum);
 
+    if (!surfaceMaterial) {
+      if (++warnMtrCount == 1) {
+        fmt::printf("Warning: Reference to missing surface material.\n");
+        fmt::printf("         (Further warnings of this type squelched.)\n");
+      }
+    }
+
     if (materialNum >= summaries.size()) {
       summaries.resize(materialNum + 1);
     }
@@ -57,7 +66,8 @@ FbxMaterialsAccess::FbxMaterialsAccess(
     if (materialNum >= userProperties.size()) {
       userProperties.resize(materialNum + 1);
     }
-    if (userProperties[materialNum].empty()) {
+    if (surfaceMaterial && userProperties[materialNum].empty()) {
+
       FbxProperty objectProperty = surfaceMaterial->GetFirstProperty();
       while (objectProperty.IsValid()) {
         if (objectProperty.GetFlag(FbxPropertyFlags::eUserDefined)) {
@@ -97,6 +107,9 @@ const std::vector<std::string> FbxMaterialsAccess::GetUserProperties(const int p
 std::unique_ptr<FbxMaterialInfo> FbxMaterialsAccess::GetMaterialInfo(
     FbxSurfaceMaterial* material,
     const std::map<const FbxTexture*, FbxString>& textureLocations) {
+  if (!material) {
+    return nullptr;
+  }
   std::unique_ptr<FbxMaterialInfo> res =
       FbxStingrayPBSMaterialResolver(material, textureLocations).resolve();
   if (res == nullptr) {