3 files changed, 103 insertions, 0 deletions

diff --git a/indra/newview/llfloaterregioninfo.cpp b/indra/newview/llfloaterregioninfo.cpp
index 706f7cf943..65b4feba11 100644
--- a/indra/newview/llfloaterregioninfo.cpp
+++ b/indra/newview/llfloaterregioninfo.cpp
@@ -1392,6 +1392,62 @@ BOOL LLPanelRegionTerrainInfo::validateTextureSizes()
 	return TRUE;
 }
 
+bool LLPanelRegionTerrainInfo::validateMaterials()
+{
+    if (mMaterialTypeCtrl)
+    {
+        const LLTerrainMaterials::Type material_type = material_type_from_ctrl(mMaterialTypeCtrl);
+        const bool is_texture_selected = material_type == LLTerrainMaterials::Type::TEXTURE;
+        if (is_texture_selected) { return true; }
+    }
+
+    for (S32 i = 0; i < LLTerrainMaterials::ASSET_COUNT; ++i)
+    {
+        LLTextureCtrl* material_ctrl = mMaterialDetailCtrl[i];
+        if (!material_ctrl) { continue; }
+
+        const LLUUID& material_asset_id = material_ctrl->getImageAssetID();
+        llassert(material_asset_id.notNull());
+        if (material_asset_id.isNull()) { return false; }
+        const LLFetchedGLTFMaterial* material = gGLTFMaterialList.getMaterial(material_asset_id);
+        if (!material->isLoaded())
+        {
+            if (material->isFetching())
+            {
+                LLSD args;
+                args["MATERIAL_NUM"] = i + 1;
+                LLNotificationsUtil::add("InvalidTerrainMaterialNotLoaded", args);
+            }
+            else // Loading failed
+            {
+                LLSD args;
+                args["MATERIAL_NUM"] = i + 1;
+                LLNotificationsUtil::add("InvalidTerrainMaterialLoadFailed", args);
+            }
+            return false;
+        }
+
+        if (material->mDoubleSided)
+        {
+            LLSD args;
+            args["MATERIAL_NUM"] = i + 1;
+            LLNotificationsUtil::add("InvalidTerrainMaterialDoubleSided", args);
+            return false;
+        }
+        if (material->mAlphaMode != LLGLTFMaterial::ALPHA_MODE_OPAQUE && material->mAlphaMode != LLGLTFMaterial::ALPHA_MODE_MASK)
+        {
+            LLSD args;
+            args["MATERIAL_NUM"] = i + 1;
+            const char* alpha_mode = material->getAlphaMode();
+            args["MATERIAL_ALPHA_MODE"] = alpha_mode;
+            LLNotificationsUtil::add("InvalidTerrainMaterialAlphaMode", args);
+            return false;
+        }
+    }
+
+    return true;
+}
+
 BOOL LLPanelRegionTerrainInfo::validateTextureHeights()
 {
 	for (S32 i = 0; i < CORNER_COUNT; ++i)
@@ -1668,6 +1724,12 @@ BOOL LLPanelRegionTerrainInfo::sendUpdate()
 		return FALSE;
 	}
 
+    // Prevent applying unsupported alpha blend/double-sided materials
+    if (!validateMaterials())
+    {
+        return FALSE;
+    }
+
 	// Check if terrain Elevation Ranges are correct
 	if (gSavedSettings.getBOOL("RegionCheckTextureHeights") && !validateTextureHeights())
 	{
diff --git a/indra/newview/llfloaterregioninfo.h b/indra/newview/llfloaterregioninfo.h
index 99774e5db3..ac3a8fc717 100644
--- a/indra/newview/llfloaterregioninfo.h
+++ b/indra/newview/llfloaterregioninfo.h
@@ -254,6 +254,7 @@ public:
 	void setEnvControls(bool available);									// Whether environment settings are available for this region
 
 	BOOL validateTextureSizes();
+    bool validateMaterials();
 	BOOL validateTextureHeights();
 
 	//static void onChangeAnything(LLUICtrl* ctrl, void* userData);			// callback for any change, to enable commit button
diff --git a/indra/newview/skins/default/xui/en/notifications.xml b/indra/newview/skins/default/xui/en/notifications.xml
index c1e6e7b9f0..44807aa6c7 100644
--- a/indra/newview/skins/default/xui/en/notifications.xml
+++ b/indra/newview/skins/default/xui/en/notifications.xml
@@ -4046,6 +4046,46 @@ Replace texture [TEXTURE_NUM] with an RGB [MAX_SIZE]x[MAX_SIZE] or smaller image
 
   <notification
    icon="alertmodal.tga"
+   name="InvalidTerrainMaterialNotLoaded"
+   type="alertmodal">
+Couldn&apos;t set region materials:
+Terrain material [MATERIAL_NUM] is not loaded.
+
+Wait for the material to load, or replace material [TEXTURE_NUM] with a valid material.
+  </notification>
+
+  <notification
+   icon="alertmodal.tga"
+   name="InvalidTerrainMaterialLoadFailed"
+   type="alertmodal">
+Couldn&apos;t set region materials:
+Terrain material [MATERIAL_NUM] failed to load.
+
+Replace material [TEXTURE_NUM] with a valid material.
+  </notification>
+
+  <notification
+   icon="alertmodal.tga"
+   name="InvalidTerrainMaterialDoubleSided"
+   type="alertmodal">
+Couldn&apos;t set region materials:
+Terrain material [MATERIAL_NUM] is double-sided. Double-sided materials are not currently supported for PBR terrain.
+
+Replace material [MATERIAL_NUM] with a material with doubleSided=false.
+  </notification>
+
+  <notification
+   icon="alertmodal.tga"
+   name="InvalidTerrainMaterialAlphaMode"
+   type="alertmodal">
+Couldn&apos;t set region materials:
+Terrain material [MATERIAL_NUM] is using the unsupported alphaMode="[MATERIAL_ALPHA_MODE]".
+
+Replace material [MATERIAL_NUM] with a material with alphaMode="OPAQUE" or alphaMode="MASK".
+  </notification>
+
+  <notification
+   icon="alertmodal.tga"
    name="RawUploadStarted"
    type="alertmodal">
 Upload started. It may take up to two minutes, depending on your connection speed.