How to define and update emtpy grid/map?

Hello,

I put a Kinect sensor on a trolley and took a depth video. Then I transformed the data.

Now I just have the localisation of the camera and also the x and y values of the obstacles. What I want to do now is to define a grid/map and plot all the obstacles for every frame in this map?

Can someone please tell me how to define an empty map and update it various times with the information of an x,y array?

Thank you!