public void SetIndices(IPrimitiveReader <TMaterial> srcPrim, EncodingType encoding)
        {
            Guard.NotNull(srcPrim, nameof(srcPrim));

            var iAccessor = VertexTypes.VertexUtils.CreateIndexMemoryAccessor(srcPrim.GetIndices(), encoding);

            if (_VerticesPerPrimitive == 1)
            {
                Guard.MustBeNull(iAccessor, nameof(srcPrim));
            }
            else
            {
                Guard.NotNull(iAccessor, nameof(iAccessor));
            }

            _IndexAccessors = iAccessor;
        }