From 444534f4ffe705c1f0121aae998520ed2733dcdf Mon Sep 17 00:00:00 2001
From: SamGondelman <samuel_gondelman@alumni.brown.edu>
Date: Fri, 16 Mar 2018 13:38:45 -0700
Subject: [PATCH] model behaves correctly if missing material

(cherry picked from commit 1e89debc4e85ceccce3f72582bc422b904098e95)
---
 libraries/render-utils/src/MeshPartPayload.cpp | 14 ++++++++------
 libraries/render-utils/src/MeshPartPayload.h   |  9 ++++++---
 libraries/render-utils/src/Model.cpp           |  3 ++-
 3 files changed, 16 insertions(+), 10 deletions(-)

diff --git a/libraries/render-utils/src/MeshPartPayload.cpp b/libraries/render-utils/src/MeshPartPayload.cpp
index ecfb4847e4..5c64d4b584 100644
--- a/libraries/render-utils/src/MeshPartPayload.cpp
+++ b/libraries/render-utils/src/MeshPartPayload.cpp
@@ -47,6 +47,8 @@ template <> void payloadRender(const MeshPartPayload::Pointer& payload, RenderAr
 }
 }
 
+const graphics::MaterialPointer MeshPartPayload::DEFAULT_MATERIAL = std::make_shared<graphics::Material>();
+
 MeshPartPayload::MeshPartPayload(const std::shared_ptr<const graphics::Mesh>& mesh, int partIndex, graphics::MaterialPointer material) {
     updateMeshPart(mesh, partIndex);
     addMaterial(graphics::MaterialLayer(material, 0));
@@ -99,7 +101,7 @@ void MeshPartPayload::updateKey(bool isVisible, bool isLayered, bool canCastShad
         builder.withSubMetaCulled();
     }
 
-    if (_drawMaterials.top().material) {
+    if (topMaterialExists()) {
         auto matKey = _drawMaterials.top().material->getKey();
         if (matKey.isTranslucent()) {
             builder.withTransparent();
@@ -119,7 +121,7 @@ Item::Bound MeshPartPayload::getBound() const {
 
 ShapeKey MeshPartPayload::getShapeKey() const {
     graphics::MaterialKey drawMaterialKey;
-    if (_drawMaterials.top().material) {
+    if (topMaterialExists()) {
         drawMaterialKey = _drawMaterials.top().material->getKey();
     }
 
@@ -171,7 +173,7 @@ void MeshPartPayload::render(RenderArgs* args) {
     bindMesh(batch);
 
     // apply material properties
-    RenderPipelines::bindMaterial(_drawMaterials.top().material, batch, args->_enableTexturing);
+    RenderPipelines::bindMaterial(!_drawMaterials.empty() ? _drawMaterials.top().material : DEFAULT_MATERIAL, batch, args->_enableTexturing);
     args->_details._materialSwitches++;
 
     // Draw!
@@ -356,7 +358,7 @@ void ModelMeshPartPayload::updateKey(bool isVisible, bool isLayered, bool canCas
         builder.withDeformed();
     }
 
-    if (_drawMaterials.top().material) {
+    if (topMaterialExists()) {
         auto matKey = _drawMaterials.top().material->getKey();
         if (matKey.isTranslucent()) {
             builder.withTransparent();
@@ -387,7 +389,7 @@ void ModelMeshPartPayload::setShapeKey(bool invalidateShapeKey, bool isWireframe
     }
 
     graphics::MaterialKey drawMaterialKey;
-    if (_drawMaterials.top().material) {
+    if (topMaterialExists()) {
         drawMaterialKey = _drawMaterials.top().material->getKey();
     }
 
@@ -469,7 +471,7 @@ void ModelMeshPartPayload::render(RenderArgs* args) {
     bindMesh(batch);
 
     // apply material properties
-    RenderPipelines::bindMaterial(_drawMaterials.top().material, batch, args->_enableTexturing);
+    RenderPipelines::bindMaterial(!_drawMaterials.empty() ? _drawMaterials.top().material : DEFAULT_MATERIAL, batch, args->_enableTexturing);
     args->_details._materialSwitches++;
 
     // Draw!
diff --git a/libraries/render-utils/src/MeshPartPayload.h b/libraries/render-utils/src/MeshPartPayload.h
index 087550345d..08ad7a8311 100644
--- a/libraries/render-utils/src/MeshPartPayload.h
+++ b/libraries/render-utils/src/MeshPartPayload.h
@@ -65,15 +65,18 @@ public:
     graphics::Mesh::Part _drawPart;
 
     size_t getVerticesCount() const { return _drawMesh ? _drawMesh->getNumVertices() : 0; }
-    size_t getMaterialTextureSize() { return _drawMaterials.top().material ? _drawMaterials.top().material->getTextureSize() : 0; }
-    int getMaterialTextureCount() { return _drawMaterials.top().material ? _drawMaterials.top().material->getTextureCount() : 0; }
-    bool hasTextureInfo() const { return _drawMaterials.top().material ? _drawMaterials.top().material->hasTextureInfo() : false; }
+    size_t getMaterialTextureSize() { return topMaterialExists() ? _drawMaterials.top().material->getTextureSize() : 0; }
+    int getMaterialTextureCount() { return topMaterialExists() ? _drawMaterials.top().material->getTextureCount() : 0; }
+    bool hasTextureInfo() const { return topMaterialExists() ? _drawMaterials.top().material->hasTextureInfo() : false; }
 
     void addMaterial(graphics::MaterialLayer material);
     void removeMaterial(graphics::MaterialPointer material);
 
 protected:
+    static const graphics::MaterialPointer DEFAULT_MATERIAL;
     render::ItemKey _itemKey{ render::ItemKey::Builder::opaqueShape().build() };
+
+    bool topMaterialExists() const { return !_drawMaterials.empty() && _drawMaterials.top().material; }
 };
 
 namespace render {
diff --git a/libraries/render-utils/src/Model.cpp b/libraries/render-utils/src/Model.cpp
index 2617ef12ad..70f873734a 100644
--- a/libraries/render-utils/src/Model.cpp
+++ b/libraries/render-utils/src/Model.cpp
@@ -1604,7 +1604,8 @@ void Model::createVisibleRenderItemSet() {
         int numParts = (int)mesh->getNumParts();
         for (int partIndex = 0; partIndex < numParts; partIndex++) {
             _modelMeshRenderItems << std::make_shared<ModelMeshPartPayload>(shared_from_this(), i, partIndex, shapeID, transform, offset);
-            _modelMeshMaterialNames.push_back(getGeometry()->getShapeMaterial(shapeID)->getName());
+            auto material = getGeometry()->getShapeMaterial(shapeID);
+            _modelMeshMaterialNames.push_back(material ? material->getName() : "");
             _modelMeshRenderItemShapes.emplace_back(ShapeInfo{ (int)i });
             shapeID++;
         }