Fixed potential crash when switching 2D/3D visual
Fixed potential crash when switching 2D/3D visual

DmitrySigaev/gpac-sf,DmitrySigaev/gpac-sf,DmitrySigaev/gpac-sf,DmitrySigaev/gpac-sf,DmitrySigaev/gpac-sf,DmitrySigaev/gpac-sf