Interactive Grid GDExtension

InteractiveGrid is a Godot 4.5 GDExtension that allows player interaction with a 3D grid, including cell selection, pathfinding, and hover highlights.

Features

• Fully compatible with Godot 4.5.
• Highlight cells when hovering the mouse over them.
• Select individual cells.
• Calculate paths from a global position to selected cells using AStar2D.
• Choose movement type: orthogonal (4 directions) or diagonal (8 directions) directly from the editor.
• Customize the grid from the editor: grid size, cell size, mesh, colors, and shaders.
• High performance using MultiMeshInstance3D for efficient rendering of multiple cells.
• Detect obstacles (collision mask configurable from the editor).
• Align cells with the floor (collision mask configurable from the editor).
• Hide distant cells to focus on the relevant area.

Demo Example GDScript

# # =================================================================================================
# File: interactive_grid.gd
#
# Summary: Script extending InteractiveGrid to handle player interaction with the grid.
#
# Node: InteractiveGrid (InteractiveGrid).
#
# Last modified: October 01, 2025
#
# This file is part of the InteractiveGrid GDExtension Source Code.
# Repository: https://github.com/antoinecharruel/interactive_grid_gdextension
#
# Version InteractiveGrid: 1.0.0
# Version: Godot Engine v4.5.stable.steam - https://godotengine.org
#
# Author: Antoine Charruel
# =================================================================================================

extends InteractiveGrid

@onready var pawn: CharacterBody3D = $"../Pawn"
@onready var interactive_grid: InteractiveGrid = $"."
@onready var main: Node3D = $".."

func _ready() -> void:
    # /*F+F++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
    # Summary: Called when the node enters the scene tree for the first time.
    #
    # Last Modified: October 01, 2025
    
    pass
    # ----------------------------------------------------------------------------------------F-F*/

func _process(delta: float) -> void:
    # /*F+F++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
    # Summary: Called every frame. 'delta' is the elapsed time since the previous frame.
    #
    # Last Modified: October 01, 2025
    
    if interactive_grid != null && pawn != null:
        # Highlight the cell under the mouse.
        if interactive_grid.get_selected_cells().is_empty():
            interactive_grid.highlight_on_hover(main.get_ray_intersection_position())
    # ----------------------------------------------------------------------------------------F-F*/
    
func _input(event):
    # /*F+F++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
    # Summary: Handles mouse input events for the InteractiveGrid.
    #
    # Last Modified: October 01, 2025
    
    if event is InputEventMouseButton and event.button_index == MOUSE_BUTTON_RIGHT:
    # --------------------------------------------------------------------
    #  RIGHT MOUSE CLICK.
    # --------------------------------------------------------------------
        if event.pressed:
            print("Right button is held down at ", event.position)
            
            if interactive_grid != null && pawn != null:
                # Makes the grid visible.
                interactive_grid.set_grid_visible(true)
                # Centers the grid.
                # ! Info: every time center is called, the state of the cells is reset.
                interactive_grid.center(pawn.global_position)
                 # Hides distant cells.
                var index_pawn_cell = interactive_grid.get_cell_index_from_global_position(pawn.global_position)
                interactive_grid.hide_distant_cells(index_pawn_cell, 6)
        else:
            print("Right button was released")


    if event is InputEventMouseButton and event.button_index == MOUSE_BUTTON_LEFT:
    # --------------------------------------------------------------------
    #  LEFT MOUSE CLICK.
    # --------------------------------------------------------------------
        if event.pressed:
            print("Left button is held down at ", event.position)
            
            if interactive_grid != null && pawn != null:
                
                # Select a cell.
                if interactive_grid.get_selected_cells().is_empty():
                    interactive_grid.select_cell(main.get_ray_intersection_position())
                
                # Retrieve the selected cells.
                var selected_cells: Array = interactive_grid.get_selected_cells()
                if selected_cells.size() > 0:
                    print("Selected cell index: ", selected_cells[0])
                    print("Selected cells: ", selected_cells)
                    print("Position of the selected cell: ", interactive_grid.get_cell_golbal_position(selected_cells[0]))

                    var cell_index_pawn = interactive_grid.get_cell_index_from_global_position(interactive_grid.get_grid_center_position())
                    print("Pawn index: ", cell_index_pawn)
                    
                    # Retrieve the path.
                    var path: PackedInt64Array
                    path = interactive_grid.get_path(cell_index_pawn, selected_cells[0]) # only the first one.
                    #path = interactive_grid.get_path(cell_index_pawn, interactive_grid.get_latest_selected()) # the last one.
                    print("Last selected cell:", interactive_grid.get_latest_selected())
                    print("Path:", path)
                    
                    # Highlight the path.
                    interactive_grid.highlight_path(path)
        else:
            print("Right button was released")