Cutting Holes Into Mesh

We be cutting holes :)

demo/main.tscn

@@ -1,19 +1,24 @@
-[gd_scene load_steps=3 format=3 uid="uid://dvgdgi3jrhrvt"]
+[gd_scene load_steps=4 format=3 uid="uid://dvgdgi3jrhrvt"]
 
-[ext_resource type="Script" uid="uid://dysaws7hlg4td" path="res://scripts/test.gd" id="1_ig7tw"]
+[ext_resource type="Script" uid="uid://cs057402w7w17" path="res://scripts/camera.gd" id="2_0xm2m"]
+[ext_resource type="Script" uid="uid://42cwsrh6jyns" path="res://scripts/destructable_wall.gd" id="3_h2yge"]
 
 [sub_resource type="Environment" id="Environment_ig7tw"]
 
 [node name="Node3D" type="Node3D"]
-script = ExtResource("1_ig7tw")
 
 [node name="DirectionalLight3D" type="DirectionalLight3D" parent="."]
-transform = Transform3D(0.8192554, 0.57171863, 0.04425077, 0.028913066, 0.03588575, -0.9989376, -0.5726993, 0.81966454, 0.012869433, 0, 0.54785013, 6.354968)
+transform = Transform3D(0.8192555, 0.5717188, 0.044250764, -0.5075839, 0.7589243, -0.40791288, -0.2667944, 0.31172383, 0.91194814, 0, 0.54785013, 6.354968)
 shadow_enabled = true
 
 [node name="WorldEnvironment" type="WorldEnvironment" parent="."]
 environment = SubResource("Environment_ig7tw")
 
 [node name="Camera3D" type="Camera3D" parent="."]
-transform = Transform3D(1, 0, 0, 0, 0.99687606, -0.078981146, 0, 0.078981146, 0.99687606, 1.3097496, 0.96856904, 8.280736)
+transform = Transform3D(1, 0, 0, 0, 1, 0, 0, 0, 1, 1.546, 1, 1.6508019)
 current = true
+script = ExtResource("2_0xm2m")
+
+[node name="Wall" type="Node3D" parent="."]
+script = ExtResource("3_h2yge")
+outer_polygon = PackedVector2Array(0, 2, 2, 2, 2, 0, 0, 0)

demo/project.godot

@@ -18,3 +18,11 @@ config/icon="res://icon.svg"
 [debug_draw_3d]
 
 settings/addon_root_folder="res://addons/debug_draw_3d"
+
+[input]
+
+left_click={
+"deadzone": 0.2,
+"events": [Object(InputEventMouseButton,"resource_local_to_scene":false,"resource_name":"","device":-1,"window_id":0,"alt_pressed":false,"shift_pressed":false,"ctrl_pressed":false,"meta_pressed":false,"button_mask":0,"position":Vector2(0, 0),"global_position":Vector2(0, 0),"factor":1.0,"button_index":1,"canceled":false,"pressed":false,"double_click":false,"script":null)
+]
+}

demo/scripts/camera.gd

@@ -0,0 +1,23 @@
+extends Camera3D
+
+signal wall_hit(wall_id, position, cutter)
+
+func shoot_ray() -> Dictionary:
+	var mouse_position = get_viewport().get_mouse_position()
+	var ray_length = 1000
+	var from = project_ray_origin(mouse_position)
+	var to = from + project_ray_normal(mouse_position) * ray_length
+	var space = get_world_3d().direct_space_state
+	var ray_query = PhysicsRayQueryParameters3D.new()
+	ray_query.from = from
+	ray_query.to = to
+	var raycast_result = space.intersect_ray(ray_query)
+	
+	return raycast_result
+
+func _input(event: InputEvent) -> void:
+	if event.is_action_pressed("left_click"):
+		var query_result = shoot_ray()
+		if query_result:
+			var cutter: PackedVector2Array = Cutter.circleCutter()
+			wall_hit.emit(query_result["collider_id"], query_result["position"], cutter)

demo/scripts/camera.gd.uid

@@ -0,0 +1 @@
+uid://cs057402w7w17

demo/scripts/cutters.gd

@@ -0,0 +1,24 @@
+extends Node
+
+class_name Cutter
+
+static func circleCutter(num_sides = 10, perimerter_length = 0.5) -> PackedVector2Array:
+	var line_length: float = perimerter_length/num_sides
+	var line_angle: float = 360.0/num_sides
+	var current_angle: float = 0.0
+	
+	var vectors: PackedVector2Array
+	
+	for i in num_sides:
+		var vector: Vector2 = Vector2.ZERO
+		
+		if i == 0:
+			current_angle += line_angle
+			vector = Vector2(line_length * cos(deg_to_rad(current_angle)), line_length * sin(deg_to_rad(current_angle)))
+			vectors.append(vector)
+		else:
+			current_angle += line_angle
+			vector = Vector2(vectors[i-1].x + line_length * cos(deg_to_rad(current_angle)), vectors[i-1].y + line_length * sin(deg_to_rad(current_angle)))
+			vectors.append(vector)
+	
+	return vectors

demo/scripts/cutters.gd.uid

@@ -0,0 +1 @@
+uid://cd5la8wwjk34w

demo/scripts/destructable_wall.gd

@@ -0,0 +1,103 @@
+extends Node
+
+@export var outer_polygon: PackedVector2Array
+@export var inner_polygons: Array[PackedVector2Array]
+@export var edge_non_fracture: float = 0.1
+
+@onready var camera: Camera3D = get_node("/root/Node3D/Camera3D")
+@onready var meshInstance = MeshInstance3D.new()
+@onready var parentNode = get_node("..")
+
+var depth: float:
+	set(value):
+		if value > 0:
+			depth = -value
+		depth = value
+
+var static_body: StaticBody3D
+
+func _ready() -> void:
+	assert(camera, "camera was not found")
+	assert(len(outer_polygon) > 2, "outer polygon does not meet the required length")
+	
+	camera.connect("wall_hit", _handle_hit_signal)
+	
+	self.add_child(meshInstance)
+	_draw()
+
+func _draw():
+	var vector_indexes = GeoPolyTriangulization.triangulate(outer_polygon, inner_polygons)
+	var vectors = []
+	
+	vectors.append_array(outer_polygon)
+	for ip in inner_polygons:
+		vectors.append_array(ip)
+	
+	var meshGenerator = GeoPolyMesh.new(vector_indexes, vectors)
+	var mesh = meshGenerator.commit_mesh()
+	
+	meshInstance.mesh = mesh
+	meshInstance.create_trimesh_collision()
+	static_body = _find_static_body()
+
+func _re_draw():
+	meshInstance.remove_child(static_body)
+	static_body.queue_free()
+	
+	var vector_indexes = GeoPolyTriangulization.triangulate(outer_polygon, inner_polygons)
+	var vectors = []
+	
+	vectors.append_array(outer_polygon)
+	for ip in inner_polygons:
+		vectors.append_array(ip)
+	
+	var meshGenerator = GeoPolyMesh.new(vector_indexes, vectors)
+	var mesh = meshGenerator.commit_mesh()
+	
+	meshInstance.mesh = mesh
+	meshInstance.create_trimesh_collision()
+	static_body = _find_static_body()
+
+
+func _handle_hit_signal(wall_id: int, position: Vector3, cutter: PackedVector2Array):
+	# validate that the hit was to this wall, if not return
+	if wall_id != static_body.get_instance_id():
+		return
+
+	var hole_position_offset = self.position + position
+	var hole_vector2_offset = Vector2(hole_position_offset.x, hole_position_offset.y)
+	
+	# translate the cutter
+	var hole_vectors = Transform2D(0, hole_vector2_offset) * cutter
+	
+	_add_hole(hole_vectors)
+	
+	_re_draw()
+
+func _add_hole(new_hole: PackedVector2Array):
+	var values_to_remove = []
+	
+	var merged: PackedVector2Array = new_hole
+	for index in range(len(self.inner_polygons)):
+		var result = Geometry2D.merge_polygons(merged, self.inner_polygons[index])
+		
+		if len(result) == 1:
+			merged = result[0]
+			values_to_remove.append(self.inner_polygons[index])
+		elif len(result) > 1:
+			# need to check that they have no overlapping area if they do clip
+			var overlap = Geometry2D.intersect_polygons(result[0], result[1])
+			
+			if len(overlap) != 0:
+				merged = Geometry2D.clip_polygons(result[0], result[1])[0]
+				values_to_remove.append(self.inner_polygons[index])
+	
+	for i in values_to_remove:
+		self.inner_polygons.erase(i)
+	
+	inner_polygons.append(merged)
+
+func _find_static_body():
+	for child in meshInstance.get_children():
+		if child is StaticBody3D:
+			return child

demo/scripts/destructable_wall.gd.uid

@@ -0,0 +1 @@
+uid://42cwsrh6jyns

demo/scripts/geometry/geopolymesh.gd

@@ -14,8 +14,8 @@ var _v_points = []
 
 var edges = {}
 
-func _init(vector_indexes: PackedInt32Array, vector_points: PackedVector2Array, depth: float = -2.0):
+func _init(vector_indexes: PackedInt32Array, vector_points: PackedVector2Array, depth: float = -0.1):
-	assert(len(vector_indexes) % 3 == 0, "Number of vertex points is not divisible by 3, invalid triangle verticies")
+	assert(len(vector_indexes) % 3 == 0 && len(vector_indexes) != 0, "Number of vertex points is not divisible by 3, invalid triangle verticies")
 	surface_array.resize(Mesh.ARRAY_MAX)
 	
 	self._v_indexes = vector_indexes
@@ -39,7 +39,6 @@ func calculate_area(mesh_vertices: PackedVector2Array) -> float:
 	
 	return result * 0.5
 
-
 # edges are any verticies that share only on triangle
 func _pre_process_edges():
 	var faces = UTIL.chunk_array(self._v_indexes, 3)
@@ -144,9 +143,6 @@ func _draw_sides(depth: float):
 			var v3 = self._v_points[outline_edges_ordered[outline_vector_ind + 1]]+ Vector3(0, 0, depth)
 			
 			var n1 = self._calc_triangle_normal(v2, v1, v0)
-			#
-			#print(v0, ", ", v1, ", ", v2, ", ", v3)
-			#print(n1)
 			
 			self.verts.append_array([v0, v1, v2, v1, v3, v2])
 			self.normals.append_array([n1, n1, n1, n1, n1, n1])

demo/scripts/geometry/geopolytriangulization.gd

@@ -4,37 +4,8 @@ extends Node
 # a triangulized Polygon with holes
 class_name GeoPolyTriangulization
 
-# triangles are made by 3 vector
-const CHUNK_RESULT: int = 3
-
-# the boundary polygon
-var _outer_polygon: PackedVector2Array
-
-# inner polygons (holes)
-var _inner_polygons: Array[PackedVector2Array]
-
-# all vector points defined by outer and inner polygons
-var vectors: PackedVector2Array = []
-
-var _edge_safety: float = 0.0
-
-func _init(outer_polygon: PackedVector2Array, inner_polygons: Array[PackedVector2Array], edge_safety: float):
-	self._outer_polygon = outer_polygon
-	self._edge_safety = edge_safety
-
-	# calulate boundary
-	var hole_boundary = Geometry2D.offset_polygon(outer_polygon, self._edge_safety)[0]
-	
-	for ip in inner_polygons:
-		var new_hole = Geometry2D.intersect_polygons(hole_boundary, ip)[0]
-		self._inner_polygons.append(new_hole)
-	
-	self.vectors.append_array(self._outer_polygon)
-	
-	for inner_polygon in self._inner_polygons:
-		self.vectors.append_array(inner_polygon)
-
 # returns all triangles generated by ear clipping the outer and inner polygons
-func triangulate() -> PackedInt32Array:
+static func triangulate(outer_polygon: PackedVector2Array, inner_polygons: Array[PackedVector2Array]) -> PackedInt32Array:
 	var triag = Triangulization.new()
-	return triag.triangulate_with_holes(self._outer_polygon, self._inner_polygons)
+	var result = triag.triangulate_with_holes(outer_polygon, inner_polygons)
+	return result

demo/scripts/test.gd

@@ -1,29 +0,0 @@
-extends Node
-
-@onready var meshInstance = MeshInstance3D.new()
-
-var lines = []
-
-func _process(delta: float) -> void:
-	for l in lines:
-		DebugDraw3D.draw_lines(l, Color.DARK_RED)
-	
-	meshInstance.rotate(Vector3.UP, (0.9 * delta))
-	meshInstance.rotate(Vector3.RIGHT, (0.9 * delta))
-
-func _ready() -> void:
-	var p1 = [Vector2(4, 0), Vector2(4, 4), Vector2(0, 4), Vector2(0, 0)]
-	var p2 = [Vector2(0, 2), Vector2(0, 1), Vector2(2, 1), Vector2(2, 2)]
-	var p3 = [Vector2(2, 2), Vector2(2, 1), Vector2(4, 1), Vector2(4, 2)]
-
-	
-	var trianglizationInstance = GeoPolyTriangulization.new(PackedVector2Array(p1), [PackedVector2Array(p2), PackedVector2Array(p3)], -0.001)
-	var vector_indexes = trianglizationInstance.triangulate()
-	var vectors_points = trianglizationInstance.vectors
-	
-	var meshGenerator = GeoPolyMesh.new(vector_indexes, vectors_points)
-	var mesh = meshGenerator.commit_mesh()
-	
-	meshInstance.mesh = mesh
-	
-	add_child(meshInstance)

demo/scripts/test.gd.uid

@@ -1 +0,0 @@
-uid://dysaws7hlg4td