Question about grids on board for Othello game

I have imported and applied the board model and material onto the scene. It looks good. However, I'm still not sure how I can set up those grids in order to determine where those pieces could be placed. Here is the image of my board:

I also have piece model and texture as assets. Right now what I want to do is to make sure that when mouse clicks on one grid, I can place a piece onto that grid (just like what I did on the image except that I placed that piece in that grid manually). I'm thinking about adding a collider onto each grid, but even for this I have no idea what I should do after placing those colliders. Perhaps there is a better way? Or how should I continue what I have done? Looking for your opinions, thanks!

 

Just find the point on the board that was clicked, by doing a raycast with a simple box collider. Then simply do the math — you know how wide and tall the board is, and where it's positioned, so it's just a bit of arithmetic to find the row and column.

 

The center point of the board is the origin, each grid is a 1x1 square. I'm not sure how to do the detection with raycast. Could you explain in detail a bit more?
Sorry for the fact that I'm a slow learner.

 

For figuring out what was clicked, couldn't you also add an on-click type of method to the square if you made it out of lots of small square objects? If the board is one big object, though, that won't work.

To keep track of where pieces are, you could create a Board object with a Piece[,] array. That's what I ended up doing for my Tetris game, to track where blocks are. I did orient my tetris board so that the bottom left position for a block would be positioned at (0,0), because that made Board's arithmetic super easy.

 

Raycasting is basically just firing a laser in a direction, and then you get information where it hit and what object. In this case, you'll want to fire a ray from the camera from the mouse position (basically straight out the camera wherever the mouse is). This page explains how to do this.

Now, if your board has a box collider on it, you'll hit the board and get the RaycastHit.point to tell you the coordinates of where you hit. Since you know the board is at the origin, and you know the size of the squares, you can find the correct square that was hit using math.



Where the blue dot is the raycast hit point, which I've used x=1.6 and y=1.6 as an example.

 

Does the board or view ever move? If not you can just convert the mouse position to a board position. As simple as dividing by the size of the screen.

 

I will look at that, thanks a lot!

By the way, does RaycastHit.point return the value in terms of world space? For example, now the origin is at the center of the lower-left grid. And I added a box collider to the board. Now the board position is (3.5, 0, 3.5). Now if RaycastHit hits the center of the lower-left grid, will the coordinate be (0, 0, 0) (or whatever the y value is which is not mattering)?

 

No, neither the board nor the camera would move. I moved the board so that the origin now is at the center of the lower-left grid of the board.

 

RaycastHit.point is in world space.

 

Okay, thanks! I will try that and let you know if I have further questions!