Can't see what FDynamicMeshBuilder draws

Development Programming & Scripting C++
1

I’m making an editor plugin, implementing a class that inherits from USingleSelectionTool (UInteractiveTool)

Inside it’s Render method I add some vertices and triangles to a FDynamicMeshBuilder and call to Draw:





void UPainterTool::Render(IToolsContextRenderAPI* RenderAPI)
{
    FPrimitiveDrawInterface* PDI = RenderAPI->GetPrimitiveDrawInterface();
    FDynamicMeshBuilder meshBuilder = FDynamicMeshBuilder(PDI->View->GetFeatureLevel());

    meshBuilder.ReserveVertices(8);
    meshBuilder.ReserveTriangles(12);
    FDynamicMeshVertex v0;
    v0.Position = FVector(0.0f, 0.0f, 0.0f);
    FDynamicMeshVertex v1;
    v1.Position = FVector(10.0f, 0.0f, 0.0f);
    /*...set several vertices positions, to make a cube*/


    auto index0 = meshBuilder.AddVertex(v0);
    /*Add more vertices and keep ids...*/
    meshBuilder.AddTriangle(index0, index1, index2);

    /*add more triangles...*/

    FMatrix position = FMatrix::Identity;
    meshBuilder.Draw(PDI, position, GEngine->WireframeMaterial->GetRenderProxy(), 1);

    UMeshSurfacePointTool::Render(RenderAPI);
}

I guess my code should render at least one cube in the world origin, but it shows nothing.

And I have also a question: could a FDynamicMeshBuilder be reused for several Draw calls? I’d like to pass several matrices changing position and scale?