How is 3d point converted to 1D representation in buffer

[shubham-shahh]

Hi @bigsuperZZZX @USTfgaoaa , my understanding of functions such as GridMap::globalIdx2BufIdx and GridMap::globalIdx2InfBufIdx, is that it converts 3D point to 1D representation for a 1D buffer, correct me If I am wrong I want to understand the working of the function mentioned below

inline int GridMap::globalIdx2BufIdx(const Eigen::Vector3i &id)
{
  int x_buffer = (id(0) - md_.ringbuffer_origin3i_(0)) % md_.ringbuffer_size3i_(0);
  int y_buffer = (id(1) - md_.ringbuffer_origin3i_(1)) % md_.ringbuffer_size3i_(1);
  int z_buffer = (id(2) - md_.ringbuffer_origin3i_(2)) % md_.ringbuffer_size3i_(2);
  if (x_buffer < 0)
    x_buffer += md_.ringbuffer_size3i_(0);
  if (y_buffer < 0)
    y_buffer += md_.ringbuffer_size3i_(1);
  if (z_buffer < 0)
    z_buffer += md_.ringbuffer_size3i_(2);

  return md_.ringbuffer_size3i_(0) * md_.ringbuffer_size3i_(1) * z_buffer + md_.ringbuffer_size3i_(0) * y_buffer + x_buffer;
}

I want to understand the working of this function, how you convert a 3D to 1D, and what's the intuition.

[bigsuperZZZX]

You could refer to this paper for more details: "Real-Time Trajectory Replanning for MAVs using Uniform B-splines and a 3D Circular Buffer".

[shubham-shahh]

thanks, @bigsuperZZZX, I'll look into it. Ill close this issue for now