4 files changed, 48 insertions, 7 deletions
diff --git a/indra/llprimitive/llgltfmaterial.cpp b/indra/llprimitive/llgltfmaterial.cpp
index 5442af33d0..a8dad89292 100644
--- a/indra/llprimitive/llgltfmaterial.cpp
+++ b/indra/llprimitive/llgltfmaterial.cpp
@@ -392,11 +392,23 @@ bool LLGLTFMaterial::setBaseMaterial()
 {
     const LLGLTFMaterial old_override = *this;
     *this = sDefault;
-    // Preserve the texture transforms
-    mTextureTransform = old_override.mTextureTransform;
+    setBaseMaterial(old_override);
     return *this != old_override;
 }
 
+bool LLGLTFMaterial::isClearedForBaseMaterial()
+{
+    LLGLTFMaterial cleared_override = sDefault;
+    cleared_override.setBaseMaterial(*this);
+    return *this == cleared_override;
+}
+
+// For material overrides only. Copies transforms from the old override.
+void LLGLTFMaterial::setBaseMaterial(const LLGLTFMaterial& old_override_mat)
+{
+    mTextureTransform = old_override_mat.mTextureTransform;
+}
+
 
 // static
 void LLGLTFMaterial::hackOverrideUUID(LLUUID& id)
diff --git a/indra/llprimitive/llgltfmaterial.h b/indra/llprimitive/llgltfmaterial.h
index 7bfcd3bf66..dec7b696f8 100644
--- a/indra/llprimitive/llgltfmaterial.h
+++ b/indra/llprimitive/llgltfmaterial.h
@@ -185,6 +185,8 @@ public:
     // For material overrides only. Clears most properties to
     // default/fallthrough, but preserves the transforms.
     bool setBaseMaterial();
+    // True if setBaseMaterial() was just called
+    bool isClearedForBaseMaterial();
 
 private:
 
@@ -193,5 +195,7 @@ private:
 
     template<typename T>
     void writeToTexture(tinygltf::Model& model, T& texture_info, TextureInfo texture_info_id, const LLUUID& texture_id) const;
+
+    void setBaseMaterial(const LLGLTFMaterial& old_override_mat);
 };
 
diff --git a/indra/llprimitive/lltextureentry.cpp b/indra/llprimitive/lltextureentry.cpp
index a0d5793dcc..49f67918f8 100644
--- a/indra/llprimitive/lltextureentry.cpp
+++ b/indra/llprimitive/lltextureentry.cpp
@@ -514,15 +514,15 @@ S32 LLTextureEntry::setBumpShiny(U8 bump_shiny)
 	return TEM_CHANGE_NONE;
 }
 
-void LLTextureEntry::setGLTFMaterial(LLGLTFMaterial* material)
+void LLTextureEntry::setGLTFMaterial(LLGLTFMaterial* material, bool local_origin)
 { 
     if (material != getGLTFMaterial())
     {
         // assert on precondtion:
-        // whether or not mGLTFMaterial is null, any existing override should have been nulled out 
+        // whether or not mGLTFMaterial is null, any existing override should have been cleared
         // before calling setGLTFMaterial
         // NOTE: if you're hitting this assert, try to make sure calling code is using LLViewerObject::setRenderMaterialID
-        llassert(getGLTFMaterialOverride() == nullptr);
+        llassert(!local_origin || getGLTFMaterialOverride() == nullptr || getGLTFMaterialOverride()->isClearedForBaseMaterial());
 
         mGLTFMaterial = material;
         if (mGLTFMaterial == nullptr)
@@ -538,6 +538,27 @@ void LLTextureEntry::setGLTFMaterialOverride(LLGLTFMaterial* mat)
     mGLTFMaterialOverrides = mat; 
 }
 
+S32 LLTextureEntry::setBaseMaterial()
+{
+    S32 changed = TEM_CHANGE_NONE;
+
+    if (mGLTFMaterialOverrides)
+    {
+        if (mGLTFMaterialOverrides->setBaseMaterial())
+        {
+            changed = TEM_CHANGE_TEXTURE;
+        }
+
+        if (LLGLTFMaterial::sDefault == *mGLTFMaterialOverrides)
+        {
+            mGLTFMaterialOverrides = nullptr;
+            changed = TEM_CHANGE_TEXTURE;
+        }
+    }
+
+    return changed;
+}
+
 LLGLTFMaterial* LLTextureEntry::getGLTFRenderMaterial() const
 { 
     if (mGLTFRenderMaterial.notNull())
@@ -545,7 +566,7 @@ LLGLTFMaterial* LLTextureEntry::getGLTFRenderMaterial() const
         return mGLTFRenderMaterial;
     }
     
-    llassert(getGLTFMaterialOverride() == nullptr);
+    llassert(getGLTFMaterialOverride() == nullptr || getGLTFMaterialOverride()->isClearedForBaseMaterial());
     return getGLTFMaterial();
 }
 
diff --git a/indra/llprimitive/lltextureentry.h b/indra/llprimitive/lltextureentry.h
index d94e14bd73..9a81181f3a 100644
--- a/indra/llprimitive/lltextureentry.h
+++ b/indra/llprimitive/lltextureentry.h
@@ -195,12 +195,16 @@ public:
 	enum { MF_NONE = 0x0, MF_HAS_MEDIA = 0x1 };
 
     // GLTF asset
-    void setGLTFMaterial(LLGLTFMaterial* material);
+    void setGLTFMaterial(LLGLTFMaterial* material, bool local_origin = true);
     LLGLTFMaterial* getGLTFMaterial() const { return mGLTFMaterial; }
 
     // GLTF override
     LLGLTFMaterial* getGLTFMaterialOverride() const { return mGLTFMaterialOverrides; }
     void setGLTFMaterialOverride(LLGLTFMaterial* mat);
+    // Clear most overrides so the render material better matches the material
+    // ID (preserve transforms). If the overrides become passthrough, set the
+    // overrides to nullptr.
+    S32 setBaseMaterial();
 
     // GLTF render material
     // nuanced behavior here -- if there is no render material, fall back to getGLTFMaterial, but ONLY for the getter, not the setter