public void GetNormals(IntPtr faceHandle, List <Vector3> normals)
{
IntPtr normalsHandle = IntPtr.Zero;
int verticesNum = 0;
ExternApi.ArAugmentedFace_getMeshNormals(m_NativeSession.SessionHandle, faceHandle,
ref normalsHandle, ref verticesNum);
int floatNum = verticesNum * 3;
if (m_TempNormals == null || m_TempNormals.Length != floatNum)
{
m_TempNormals = new float[floatNum];
}
Marshal.Copy(normalsHandle, m_TempNormals, 0, floatNum);
normals.Clear();
normals.Capacity = verticesNum;
for (int i = 0; i < floatNum; i += 3)
{
normals.Add(new Vector3(m_TempNormals[i], m_TempNormals[i + 1], -m_TempNormals[i + 2]));
}
}