Get iso position using mouse position in iso grid graph

I have a iso metric grid graph with the following values

I want to map the mouse position to the iso grid node position something like:

This is how I am trying to do it :

 private void debugCurrentNode() {
        float mouseX = Mouse.current.position.x.ReadValue();
        float mouseY = Mouse.current.position.y.ReadValue();    
        Vector2 curMouseWorldPos = Camera.main.ScreenToWorldPoint(new Vector3(mouseX, mouseY, 0));
      Debug.Log("ISO POSTION:" + XYToIso(nNInfo.position));
    Vector3 XYToIso(Vector3 v) {
        float nodeSize = MapManager.Instance.aStarGridGraph.nodeSize;
        Vector3 normalizeToNodeSize = v * nodeSize;
        // not sure how to use this
        float angle = MapManager.Instance.aStarGridGraph.isometricAngle;

        float isoX = normalizeToNodeSize.y + normalizeToNodeSize.x;
        float isoY = 0.5f * (normalizeToNodeSize.y - normalizeToNodeSize.x);
        return new Vector3(isoX, isoY, 0);

but it ain’t giving me the result , won’t lie ,I don’t really understand the math but been doing a trial and error thing ,also is there something in the library itself I can use to achieve ?

There’s no method to do this directly. But I suppose you could get the closest node to the cursor and check the coordinates of that?

var node = as GridNodeBase;
var xz = node.CoordinatesInGrid;

There’s also the transform field on the graph which maps from graph space (where 1 unit is one node) to world space.

var grid =;
var graphSpacePoint = grid.transform.InverseTransform(mousePosition);

thanks for your response, it looks like the above works, but it looks like it sets the origin to botton edge of the grid, see video:

I can probably offset it using the grid width and height but I thought that is what the center parameter of the gridGraph was for , wasn’t it?


Internally, the origin of the graph is always in the bottom-left corner (node coordinates (0,0)). The pivot point picker in the inspector is just for convenience when editing the graph settings.