message: Fix regression with getDefaultInstance().
  This caused color writes to be disabled in our "hello triangle" samples.
  Fixes
diff: @@ -76,9 +76,15 @@ FMaterialInstance::FMaterialInstance(FEngine& engine, FMaterial const* material)
  void FMaterialInstance::initDefaultInstance(FEngine& engine, FMaterial const* material) {
  mMaterial = material;
  + const RasterState& rasterState = mMaterial->getRasterState();
  +
  // We inherit the resolved culling mode rather than the builder-set culling mode.
  // This preserves the property whereby double-sidedness automatically disables culling.
  - mCulling = mMaterial->getRasterState().culling;
  + mCulling = rasterState.culling;
  +
  + mColorWrite = rasterState.colorWrite;
  + mDepthWrite = rasterState.depthWrite;
  + mDepthFunc = rasterState.depthFunc;
  mMaterialSortingKey = RenderPass::makeMaterialSortingKey(
  material->getId(), material->generateMaterialInstanceId());
  