From c83265fd57cbbff88bfa73eb31cd9ccfe5108aa9 Mon Sep 17 00:00:00 2001
From: Aloys Baillet <aloys.baillet+github@gmail.com>
Date: Thu, 21 Apr 2022 09:39:16 +1000
Subject: [PATCH] Fixed missing material dependency on GeomSubSet

---
 pxr/usdImaging/usdImaging/meshAdapter.cpp | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/pxr/usdImaging/usdImaging/meshAdapter.cpp b/pxr/usdImaging/usdImaging/meshAdapter.cpp
index f95d0e14ae..735652bbd0 100644
--- a/pxr/usdImaging/usdImaging/meshAdapter.cpp
+++ b/pxr/usdImaging/usdImaging/meshAdapter.cpp
@@ -115,6 +115,11 @@ UsdImagingMeshAdapter::Populate(UsdPrim const& prim,
                 index->GetMaterialAdapter(materialPrim);
             if (materialAdapter) {
                 materialAdapter->Populate(materialPrim, index, nullptr);
+                // We need to register a dependency on the material prim so
+                // that geometry is updated when the material is
+                // (specifically, DirtyMaterialId).
+                // XXX: Eventually, it would be great to push this into hydra.
+                index->AddDependency(cachePath, materialPrim);
             }
         }
     }