"velocity" arrow!

arrow.blend.import

@@ -0,0 +1,64 @@
+[remap]
+
+importer="scene"
+importer_version=1
+type="PackedScene"
+uid="uid://b3ajlrwduhxpr"
+path="res://.godot/imported/arrow.blend-d567a12caad2abea5cccaab885e65266.scn"
+
+[deps]
+
+source_file="res://arrow.blend"
+dest_files=["res://.godot/imported/arrow.blend-d567a12caad2abea5cccaab885e65266.scn"]
+
+[params]
+
+nodes/root_type=""
+nodes/root_name=""
+nodes/apply_root_scale=true
+nodes/root_scale=1.0
+nodes/import_as_skeleton_bones=false
+nodes/use_node_type_suffixes=true
+meshes/ensure_tangents=true
+meshes/generate_lods=true
+meshes/create_shadow_meshes=true
+meshes/light_baking=1
+meshes/lightmap_texel_size=0.2
+meshes/force_disable_compression=false
+skins/use_named_skins=true
+animation/import=true
+animation/fps=30
+animation/trimming=false
+animation/remove_immutable_tracks=true
+animation/import_rest_as_RESET=false
+import_script/path=""
+_subresources={
+"meshes": {
+"arrow_Plane": {
+"generate/lightmap_uv": 0,
+"generate/lods": 0,
+"generate/shadow_meshes": 0,
+"lods/normal_merge_angle": 60.0,
+"save_to_file/enabled": true,
+"save_to_file/path": "res://model/arrow.res"
+}
+}
+}
+blender/nodes/visible=0
+blender/nodes/active_collection_only=false
+blender/nodes/punctual_lights=true
+blender/nodes/cameras=true
+blender/nodes/custom_properties=true
+blender/nodes/modifiers=1
+blender/meshes/colors=false
+blender/meshes/uvs=true
+blender/meshes/normals=true
+blender/meshes/export_geometry_nodes_instances=false
+blender/meshes/tangents=true
+blender/meshes/skins=2
+blender/meshes/export_bones_deforming_mesh_only=false
+blender/materials/unpack_enabled=true
+blender/materials/export_materials=1
+blender/animation/limit_playback=true
+blender/animation/always_sample=true
+blender/animation/group_tracks=true

piece.gd

@@ -52,6 +52,7 @@ var lvel_displayed := lvel
 @export var type: Piece.Type
 
 var speedometer: Label3D
+@onready var arrow := get_node_or_null("Arrow") as MeshInstance3D
 
 # TODO: much, *much* better animation is needed. ESPECIALLY if we're doing slowmo
 # (we're doing slowmo because it is SICK)
@@ -136,12 +137,15 @@ func _ready() -> void:
 	speedometer.font_size = 64
 	add_child(speedometer)
 
-#TODO: arrow!
 func format_vel(vel: Vector2) -> String:
 	if vel.is_zero_approx():
 		return ""
 	else:
-		return "%d,%d" % [vel.x,vel.y]
+		# we use abs because the arrow already indicates direction
+		return "%d,%d" % [abs(vel.x),abs(vel.y)]
 
 func _process(_delta: float) -> void:
 	speedometer.text = format_vel(lvel_displayed)
+	if arrow:
+		arrow.visible = lvel_displayed != Vector2i.ZERO
+	rotation.y = (1.0*lvel_displayed.clampi(-1,1)).angle_to(Vector2.UP)

piece/ball.tscn

@@ -1,7 +1,12 @@
-[gd_scene load_steps=3 format=3 uid="uid://bghr6ew34loyb"]
+[gd_scene load_steps=5 format=3 uid="uid://bghr6ew34loyb"]
 
 [ext_resource type="SphereMesh" uid="uid://bxuewsvlsvexw" path="res://model/ball.tres" id="1_qixli"]
 [ext_resource type="Script" uid="uid://bq3a5hhccxndn" path="res://piece.gd" id="2_c3ygy"]
+[ext_resource type="ArrayMesh" uid="uid://er57431oil1l" path="res://model/arrow.res" id="3_tqeq4"]
+
+[sub_resource type="StandardMaterial3D" id="StandardMaterial3D_uae17"]
+transparency = 1
+albedo_color = Color(1, 1, 1, 0.498039)
 
 [node name="Ball" type="MeshInstance3D"]
 transform = Transform3D(1, 0, 0, 0, 1, 0, 0, 0, 1, 0.5, 0.3, 0.5)
@@ -9,3 +14,8 @@ mesh = ExtResource("1_qixli")
 script = ExtResource("2_c3ygy")
 type = 2
 metadata/_custom_type_script = "uid://bq3a5hhccxndn"
+
+[node name="Arrow" type="MeshInstance3D" parent="."]
+transform = Transform3D(-8.74228e-09, 0, 0.2, 0, 0.2, 0, -0.2, 0, -8.74228e-09, 0.00918186, 0.0516835, -0.498354)
+mesh = ExtResource("3_tqeq4")
+surface_material_override/0 = SubResource("StandardMaterial3D_uae17")