Code:

    DefaultSerializer serializer = new DefaultSerializer();            serializer.StartSerialization();            convexShape.SerializeSingleShape(serializer);            serializer.FinishSerialization();            byte[] data = new byte[serializer.CurrentBufferSize];            System.Runtime.InteropServices.Marshal.Copy(serializer.BufferPointer, data, 0, data.Length);            using (var file = new System.IO.FileStream(path, System.IO.FileMode.Create))            {                file.Write(data, 0, data.Length);            }

Code:

    BulletWorldImporter loader = new BulletWorldImporter();            if (loader.LoadFile(path))            {                int numShape = loader.NumCollisionShapes;                Console.WriteLine(numShape);                if (numShape > 0)                {                    return new (ConvexHullShape)loader.GetCollisionShapeByIndex(0);                }            }