private PathfindingGrid BuildGrid()
{
float nodeDiam = nodeRadius * 2f;
int width = Mathf.CeilToInt(gridSize.x / nodeDiam);
int height = Mathf.CeilToInt(gridSize.y / nodeDiam);
PathfindingGrid grid = new PathfindingGrid();
grid.width = width;
grid.height = height;
grid.grid = new Unity.Collections.NativeArray <Node>(width * height, Unity.Collections.Allocator.Persistent);
grid.nodeSize = nodeDiam;
for (int x = 0; x < width; x++)
{
for (int y = 0; y < height; y++)
{
var rayOrigin = grid.GetNodePosition(x, y);
rayOrigin.y = gridHeight;
var rayDir = Vector3.down;
var ray = new Ray(rayOrigin, rayDir);
if (Physics.Raycast(ray, out RaycastHit hit, gridHeight))
{
bool obstructed = CheckCube(hit.point, nodeRadius);
Node node = new Node()
{
yPosition = hit.point.y,
walkable = !obstructed && (walkable == (walkable | (1 << hit.collider.gameObject.layer)))
};
grid.grid[y * width + x] = node;
}