I am not sure what the correct name is called but here is my problem: I have implemented a casting ray function that works as expected. However, because I am using a loose grid structure, (ie, objects that overlap multiple grids are only put into one grid), the ray cast may miss certain objects. What I need, I think is a box casting where I need to get every grid the box hits from its initial position to final position. Does anyone have such algorithm? Or pointing out to a solution to this problem, thanks!
This pic from N tutorials is a nice summary of this problem:
My ray cast implementation only hit the blue cells but as you can see, it may miss certain objects. They are only put into the grid where the x is.
Just to add I will be using this in a heated loop and so I have the additional requirement that this must be done efficiently.
EDIT: this picture illustrates why I think a box casting would work for loose grid: (The box must be bigger than the objects contained in the grid.)