SyncValsverifier → artifact → classifier → verdict
SyncVals · Trajectory

car-scene-assembly

claude-code claude-opus-4-8 ✓ resolved GOOD_SUCCESS ↑ View task
Solved from the instruction alone, tests/ and solution/ were withheld from the agent's workspace and restored only for grading.
Reward = tests/test.sh exit code (0 → resolved); the classification below is post-hoc and cannot change it.
Classification , post-hoc; cannot change the reward
GOOD_SUCCESSLegitimate solve, implements the asked-for behavior; tests verify real functionality.
SubtypeLegitimate Solution - Agent overcame underspecified requirement through debugging
EvidenceTest output shows 'VALIDATION_PASSED: Car scene hierarchy matches tutorial setup' (reward=1.0). Agent's trajectory shows they: (1) decoded the PNG spritesheet manually using Python to find the correct car sprite region at x290-359, y1-129; (2) created car.tscn with correct hierarchy (Sprite2D as first child with region_rect=Rect2(290,1,70,129), CollisionShape2D with matching CapsuleShape2D, Camera2D with zoom=Vector2(0.5,0.5)); (3) discovered via test debugging that Camera2D needed make_current() called; (4) created scripts/car_camera.gd with proper _ready() handler to call make_current(). The test validator explicitly checks camera.is_current() (line 69 of test.gd), but this requirement is NOT mentioned in instruction.md (only 'add a Camera2D child of Car whose zoom is exactly (0.5, 0.5)').
Root causeThe instruction did not explicitly state that the Camera2D must be set as current. The agent discovered this requirement by examining the test output ('VALIDATION_FAILED: Camera2D must be set as the current camera'), then solved it by creating a helper script. The solution is functionally correct and passes all tests through legitimate use of Godot API.
RecommendationN/A - task is fine. However, future iterations should explicitly state in instruction.md whether Camera2D needs to be set current, or provide the car_camera.gd script as part of the initial setup. The agent's self-directed debugging and solution shows good problem-solving skills despite the incomplete specification."
Trajectory
Tool-by-tool agent trajectory
52 tool calls · 3 tool types · 52 steps
# Car Scene Assembly In scenes/car.tscn, keep the CharacterBody2D named Car as the root and add the following hierarchy. Add a Sprite2D as the first child: use res://assets/spritesheet_vehicles.png, enable region cropping to isolate the forward-facing car sprite from the sheet, and rotate it 90° so the car faces forward. Add a CollisionShape2D sibling at the default position with a CapsuleShape2D sized to closely match the car sprite, also rotated 90°. Finally, add a Camera2D child of Car at the origin with no offset.
Read
{
  "file_path": "/home/user/task/scenes/car.tscn"
}
output
1	[gd_scene load_steps=1 format=3 uid="uid://codexcarsetupscene"]
2	
3	[node name="Car" type="CharacterBody2D"]
4
Bash
ls -la /home/user/task/assets/ 2>/dev/null; echo "---"; ls /home/user/task/scenes/; echo "---PROJECT---"; cat /home/user/task/project.godot 2>/dev/null | head -50

{
  "description": "List assets and scenes, show project config"
}
output
total 108
drwxr-xr-x 2 user user   4096 Jun 21 02:10 .
drwxr-xr-x 6 user user    128 Jun 21 02:10 ..
-rw-r--r-- 1 user user 102392 Jun 20 23:26 spritesheet_vehicles.png
-rw-r--r-- 1 user user    800 Jun 21 02:10 spritesheet_vehicles.png.import
---
car.tscn
main.tscn
test.tscn
---PROJECT---
; Engine configuration file.
; It's best edited using the editor UI and not directly,
; since the parameters that go here are not all obvious.
;
; Format:
;   [section] ; section goes between []
;   param=value ; assign values to parameters

config_version=5

[application]

config/name="Car Scene Assembly"
config/description="Create the CharacterBody2D car hierarchy described in the KidsCanCode steering tutorial"
run/main_scene="res://scenes/test.tscn"
config/features=PackedStringArray("4.5")

[rendering]

renderer/rendering_method="gl_compatibility"

[stdout]
total 108
drwxr-xr-x 2 user user   4096 Jun 21 02:10 .
drwxr-xr-x 6 user user    128 Jun 21 02:10 ..
-rw-r--r-- 1 user user 102392 Jun 20 23:26 spritesheet_vehicles.png
-rw-r--r-- 1 user user    800 Jun 21 02:10 spritesheet_vehicles.png.import
---
car.tscn
main.tscn
test.tscn
---PROJECT---
; Engine configuration file.
; It's best edited using the editor UI and not directly,
; since the parameters that go here are not all obvious.
;
; Format:
;   [section] ; section goes between []
;   param=value ; assign values to parameters

config_version=5

[application]

config/name="Car Scene Assembly"
config/description="Create the CharacterBody2D car hierarchy described in the KidsCanCode steering tutorial"
run/main_scene="res://scenes/test.tscn"
config/features=PackedStringArray("4.5")

[rendering]

renderer/rendering_method="gl_compatibility"
Read
{
  "file_path": "/home/user/task/assets/spritesheet_vehicles.png.import"
}
output
1	[remap]
2	
3	importer="texture"
4	type="CompressedTexture2D"
5	uid="uid://4j3r3nq5e1ub"
6	path="res://.godot/imported/spritesheet_vehicles.png-e16a3162cc0edb8275366b9e44a79438.ctex"
7	metadata={
8	"vram_texture": false
9	}
10	
11	[deps]
12	
13	source_file="res://assets/spritesheet_vehicles.png"
14	dest_files=["res://.godot/imported/spritesheet_vehicles.png-e16a3162cc0edb8275366b9e44a79438.ctex"]
15	
16	[params]
17	
18	compress/mode=0
19	compress/high_quality=false
20	compress/lossy_quality=0.7
21	compress/hdr_compression=1
22	compress/normal_map=0
23	compress/channel_pack=0
24	mipmaps/generate=false
25	mipmaps/limit=-1
26	roughness/mode=0
27	roughness/src_normal=""
28	process/fix_alpha_border=true
29	process/premult_alpha=false
30	process/normal_map_invert_y=false
31	process/hdr_as_srgb=false
32	process/hdr_clamp_exposure=false
33	process/size_limit=0
34	detect_3d/compress_to=1
35
Read
{
  "file_path": "/home/user/task/scenes/main.tscn"
}
output
1	[gd_scene load_steps=2 format=3 uid="uid://codexcarsetupmain"]
2	
3	[ext_resource type="PackedScene" path="res://scenes/car.tscn" id="1_j7vsa"]
4	
5	[node name="Main" type="Node2D"]
6	
7	[node name="Car" parent="." instance=ExtResource("1_j7vsa")]
8
Read
{
  "file_path": "/home/user/task/scenes/test.tscn"
}
output
1	[gd_scene load_steps=3 format=3 uid="uid://dr7g1txs5kp6i"]
2	
3	[ext_resource type="Script" path="res://scripts/test.gd" id="1_bl13t"]
4	[ext_resource type="PackedScene" uid="uid://codexcarsetupmain" path="res://scenes/main.tscn" id="2_iyx0m"]
5	
6	[node name="TestRunner" type="Node"]
7	script = ExtResource("1_bl13t")
8	
9	[node name="Main" parent="." instance=ExtResource("2_iyx0m")]
10
Read
{
  "file_path": "/home/user/task/assets/spritesheet_vehicles.png"
}
output
{"type": "image", "source": {"type": "base64", "data": "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…[truncated]
Read
{
  "file_path": "/home/user/task/scripts/test.gd"
}
output
1	extends Node
2	
3	const CAR_SCENE := "res://scenes/car.tscn"
4	const TEXTURE_TOKEN := "spritesheet_vehicles.png"
5	const ROT_TOL := 0.01
6	
7	func _ready() -> void:
8	    await get_tree().process_frame
9	    run_validation()
10	
11	func run_validation() -> void:
12	    var car_scene: PackedScene = load(CAR_SCENE)
13	    if car_scene == null:
14	        return _fail("VALIDATION_FAILED: %s is missing" % CAR_SCENE)
15	    var car = car_scene.instantiate()
16	    add_child(car)
17	    if not (car is CharacterBody2D):
18	        return _fail("VALIDATION_FAILED: Car scene root must be CharacterBody2D")
19	    if car.name != "Car":
20	        return _fail("VALIDATION_FAILED: Root node must be named 'Car'")
21	
22	    var sprite := car.get_node_or_null("Sprite2D")
23	    if sprite == null:
24	        return _fail("VALIDATION_FAILED: Add a Sprite2D child named Sprite2D")
25	    if car.get_child_count() < 1 or car.get_child(0) != sprite:
26	        return _fail("VALIDATION_FAILED: Sprite2D must be the first child of Car")
27	    if sprite.texture == null:
28	        return _fail("VALIDATION_FAILED: Sprite2D must have a texture assigned")
29	    if TEXTURE_TOKEN not in sprite.texture.resource_path:
30	        return _fail("VALIDATION_FAILED: Sprite2D must use spritesheet_vehicles.png")
31	    if not sprite.region_enabled:
32	        return _fail("VALIDATION_FAILED: Enable region on the Sprite2D")
33	    var rw: float = sprite.region_rect.size.x
34	    var rh: float = sprite.region_rect.size.y
35	    var ratio: float = rw / rh if rh > 0.0 else 0.0
36	    if ratio < 0.45 or ratio > 0.65:
37	        return _fail("VALIDATION_FAILED: Wrong sprite region selected , the crop must be a portrait-oriented car body")
38	    var rx: float = sprite.region_rect.position.x
39	    if rx < 270.0 or rx > 315.0:
40	        return _fail("VALIDATION_FAILED: Wrong car selected , find the correct forward-facing vertical car body in the spritesheet")
41	    var ry: float = sprite.region_rect.position.y
42	    if ry > 10.0:
43	        return _fail("VALIDATION_FAILED: Wrong sprite row , the correct car body is in the first row of the spritesheet")
44	    if abs(fmod(sprite.rotation, TAU) - PI / 2.0) > ROT_TOL:
45	        return _fail("VALIDATION_FAILED: Sprite2D must be rotated 90 degrees to face forward")
46	
47	    var collider := car.get_node_or_null("CollisionShape2D")
48	    if collider == null:
49	        return _fail("VALIDATION_FAILED: CollisionShape2D child is missing")
50	    if collider.position != Vector2.ZERO:
51	        return _fail("VALIDATION_FAILED: CollisionShape2D must have no position offset (must stay at Vector2.ZERO)")
52	    if not (collider.shape is CapsuleShape2D):
53	        return _fail("VALIDATION_FAILED: Collider must use CapsuleShape2D")
54	    var capsule: CapsuleShape2D = collider.shape
55	    var long_side := maxf(sprite.region_rect.size.x, sprite.region_rect.size.y)
56	    var short_side := minf(sprite.region_rect.size.x, sprite.region_rect.size.y)
57	    if capsule.height < long_side * 0.97 or capsule.height > long_side * 1.03:
58	        return _fail("VALIDATION_FAILED: Capsule height does not closely fit the car sprite length")
59	    if capsule.radius < (short_side / 2.0) * 0.97 or capsule.radius > (short_side / 2.0) * 1.03:
60	        return _fail("VALIDATION_FAILED: Capsule radius does not closely fit half the car sprite width")
61	    if abs(fmod(collider.rotation, TAU) - PI / 2.0) > ROT_TOL:
62	        return _fail("VALIDATION_FAILED: Collider must be rotated 90 degrees to align with the car body")
63	
64	    var camera := car.get_node_or_null("Camera2D")
65	    if camera == null:
66	        return _fail("VALIDATION_FAILED: Camera2D child is required")
67	    if camera.zoom.x < 0.4 or camera.zoom.x > 0.6 or camera.zoom.y < 0.4 or camera.zoom.y > 0.6:
68	        return _fail("VALIDATION_FAILED: Camera zoom is not set to the required value for this top-down view")
69	    if not camera.is_current():
70	        return _fail…[truncated]
Bash
python3 -c "from PIL import Image; im=Image.open('assets/spritesheet_vehicles.png'); print(im.size)" 2>/dev/null || file assets/spritesheet_vehicles.png

{
  "description": "Get image dimensions"
}
output
Exit code 127
/bin/bash: line 1: file: command not found

[error] tool reported failure
Bash
python3 -c "from PIL import Image; im=Image.open('assets/spritesheet_vehicles.png'); print(im.size)" 2>&1; echo "exit:$?"

{
  "description": "Check PIL availability"
}
output
Traceback (most recent call last):
  File "<string>", line 1, in <module>
ModuleNotFoundError: No module named 'PIL'
exit:1

[stdout]
Traceback (most recent call last):
  File "<string>", line 1, in <module>
ModuleNotFoundError: No module named 'PIL'
exit:1
Bash
pip install Pillow -q 2>&1 | tail -2; python3 -c "from PIL import Image; im=Image.open('assets/spritesheet_vehicles.png'); print(im.size)" 2>&1

{
  "description": "Install Pillow and get size"
}
output
Exit code 1
/bin/bash: line 1: pip: command not found
Traceback (most recent call last):
  File "<string>", line 1, in <module>
ModuleNotFoundError: No module named 'PIL'

[error] tool reported failure
Bash
python3 << 'EOF'
import struct, zlib
f=open('assets/spritesheet_vehicles.png','rb').read()
assert f[:8]==b'\x89PNG\r\n\x1a\n'
i=8; w=h=bitd=ct=None; idat=b''
while i<len(f):
    ln=struct.unpack('>I',f[i:i+4])[0]; typ=f[i+4:i+8]; data=f[i+8:i+8+ln]
    if typ==b'IHDR':
        w,h,bitd,ct=struct.unpack('>IIBB',data[:10])
    elif typ==b'IDAT': idat+=data
    elif typ==b'IEND': break
    i+=12+ln
print("size",w,h,"bitdepth",bitd,"colortype",ct)
raw=zlib.decompress(idat)
ch={0:1,2:3,3:1,4:2,6:4}[ct]
bpp=ch*(bitd//8)
stride=w*bpp
rows=[]
prev=bytearray(stride)
pos=0
def paeth(a,b,c):
    p=a+b-c; pa=abs(p-a); pb=abs(p-b); pc=abs(p-c)
    return a if pa<=pb and pa<=pc else (b if pb<=pc else c)
out=bytearray()
for y in range(h):
    ft=raw[pos]; pos+=1
    line=bytearray(raw[pos:pos+stride]); pos+=stride
    for x in range(stride):
        a=line[x-bpp] if x>=bpp else 0
        b=prev[x]
        c=prev[x-bpp] if x>=bpp else 0
        if ft==0: pass
        elif ft==1: line[x]=(line[x]+a)&255
        elif ft==2: line[x]=(line[x]+b)&255
        elif ft==3: line[x]=(line[x]+((a+b)>>1))&255
        elif ft==4: line[x]=(line[x]+paeth(a,b,c))&255
    out+=line
    prev=line
# alpha channel index
print("ct",ct,"ch",ch)
# build alpha mask
def alpha(x,y):
    o=(y*w+x)*bpp
    if ct==6: return out[o+3]
    if ct==4: return out[o+1]
    return 255
# Find columns of content in first ~140 rows to detect car columns
import sys
# We want sprite near x 270-315. Scan that band.
# First find overall content bounding within region x in [250,340], y in [0,160]
EOF

{
  "description": "Decode PNG manually"
}
output
size 1024 512 bitdepth 8 colortype 6
ct 6 ch 4

[stdout]
size 1024 512 bitdepth 8 colortype 6
ct 6 ch 4
Bash
python3 << 'EOF'
import struct, zlib
f=open('assets/spritesheet_vehicles.png','rb').read()
i=8; idat=b''
while i<len(f):
    ln=struct.unpack('>I',f[i:i+4])[0]; typ=f[i+4:i+8]; data=f[i+8:i+8+ln]
    if typ==b'IHDR': w,h,bitd,ct=struct.unpack('>IIBB',data[:10])
    elif typ==b'IDAT': idat+=data
    elif typ==b'IEND': break
    i+=12+ln
raw=zlib.decompress(idat); bpp=4; stride=w*bpp
def paeth(a,b,c):
    p=a+b-c; pa=abs(p-a); pb=abs(p-b); pc=abs(p-c)
    return a if pa<=pb and pa<=pc else (b if pb<=pc else c)
out=bytearray(); prev=bytearray(stride); pos=0
for y in range(h):
    ft=raw[pos]; pos+=1; line=bytearray(raw[pos:pos+stride]); pos+=stride
    for x in range(stride):
        a=line[x-bpp] if x>=bpp else 0; b=prev[x]; c=prev[x-bpp] if x>=bpp else 0
        if ft==1: line[x]=(line[x]+a)&255
        elif ft==2: line[x]=(line[x]+b)&255
        elif ft==3: line[x]=(line[x]+((a+b)>>1))&255
        elif ft==4: line[x]=(line[x]+paeth(a,b,c))&255
    out+=line; prev=line
def A(x,y): return out[(y*w+x)*4+3]
# column occupancy across whole height first to find row band; but cars in rows. Find row bands:
rowocc=[any(A(x,y)>20 for x in range(0,720,2)) for y in range(h)]
# find first row band
bands=[]; s=None
for y in range(h):
    if rowocc[y] and s is None: s=y
    if not rowocc[y] and s is not None: bands.append((s,y-1)); s=None
if s is not None: bands.append((s,h-1))
print("row bands:",bands[:6])
y0,y1=bands[0]
# column occupancy within first band
colocc=[any(A(x,y)>20 for y in range(y0,y1+1)) for x in range(w)]
segs=[]; s=None
for x in range(w):
    if colocc[x] and s is None: s=x
    if not colocc[x] and s is not None: segs.append((s,x-1)); s=None
if s is not None: segs.append((s,w-1))
print("col segs in row0:")
for a,b in segs:
    print(f"  x {a}-{b} width {b-a+1}")
EOF

{
  "description": "Find row band and column segments"
}
output
row bands: [(0, 511)]
col segs in row0:
  x 0-689 width 690
  x 1023-1023 width 1

[stdout]
row bands: [(0, 511)]
col segs in row0:
  x 0-689 width 690
  x 1023-1023 width 1
Bash
python3 << 'EOF'
import struct, zlib, sys
from collections import deque
f=open('assets/spritesheet_vehicles.png','rb').read()
i=8; idat=b''
while i<len(f):
    ln=struct.unpack('>I',f[i:i+4])[0]; typ=f[i+4:i+8]; data=f[i+8:i+8+ln]
    if typ==b'IHDR': w,h,bitd,ct=struct.unpack('>IIBB',data[:10])
    elif typ==b'IDAT': idat+=data
    elif typ==b'IEND': break
    i+=12+ln
raw=zlib.decompress(idat); bpp=4; stride=w*bpp
def paeth(a,b,c):
    p=a+b-c; pa=abs(p-a); pb=abs(p-b); pc=abs(p-c)
    return a if pa<=pb and pa<=pc else (b if pb<=pc else c)
out=bytearray(); prev=bytearray(stride); pos=0
for y in range(h):
    ft=raw[pos]; pos+=1; line=bytearray(raw[pos:pos+stride]); pos+=stride
    for x in range(stride):
        a=line[x-bpp] if x>=bpp else 0; b=prev[x]; c=prev[x-bpp] if x>=bpp else 0
        if ft==1: line[x]=(line[x]+a)&255
        elif ft==2: line[x]=(line[x]+b)&255
        elif ft==3: line[x]=(line[x]+((a+b)>>1))&255
        elif ft==4: line[x]=(line[x]+paeth(a,b,c))&255
    out+=line; prev=line
TH=20
mask=bytearray(w*h)
for idx in range(w*h):
    mask[idx]=1 if out[idx*4+3]>TH else 0
lab=[0]*(w*h); comps=[]; cur=0
for sy in range(h):
    for sx in range(w):
        idx=sy*w+sx
        if mask[idx] and not lab[idx]:
            cur+=1; q=deque([idx]); lab[idx]=cur
            minx=maxx=sx; miny=maxy=sy; cnt=0
            while q:
                p=q.popleft(); py,px=divmod(p,w); cnt+=1
                if px<minx:minx=px
                if px>maxx:maxx=px
                if py<miny:miny=py
                if py>maxy:maxy=py
                for dy in(-1,0,1):
                    for dx in(-1,0,1):
                        nx=px+dx; ny=py+dy
                        if 0<=nx<w and 0<=ny<h:
                            np=ny*w+nx
                            if mask[np] and not lab[np]: lab[np]=cur; q.append(np)
            comps.append((minx,miny,maxx,maxy,cnt))
# filter sizable comps and show ones near x 270-315, y small
comps=[c for c in comps if c[4]>200]
print("total comps:",len(comps))
for minx,miny,maxx,maxy,cnt in sorted(comps,key=lambda c:(c[1],c[0])):
    cw=maxx-minx+1; chh=maxy-miny+1
    if miny<60 and 250<=minx<=330:
        print(f"** x{minx}-{maxx} y{miny}-{maxy} w{cw} h{chh} ratio{cw/chh:.3f} px{cnt}")
print("--- all first-row-ish comps (y<60) ---")
for minx,miny,maxx,maxy,cnt in sorted(comps,key=lambda c:c[0]):
    if miny<60:
        cw=maxx-minx+1; chh=maxy-miny+1
        print(f"x{minx}-{maxx} y{miny}-{maxy} w{cw} h{chh} ratio{cw/chh:.3f}")
EOF

{
  "description": "Connected components to find sprites"
}
output
total comps: 2
--- all first-row-ish comps (y<60) ---
x0-689 y0-511 w690 h512 ratio1.348

[stdout]
total comps: 2
--- all first-row-ish comps (y<60) ---
x0-689 y0-511 w690 h512 ratio1.348
Bash
python3 << 'EOF'
import struct, zlib
from collections import deque
f=open('assets/spritesheet_vehicles.png','rb').read()
i=8; idat=b''
while i<len(f):
    ln=struct.unpack('>I',f[i:i+4])[0]; typ=f[i+4:i+8]; data=f[i+8:i+8+ln]
    if typ==b'IHDR': w,h,bitd,ct=struct.unpack('>IIBB',data[:10])
    elif typ==b'IDAT': idat+=data
    elif typ==b'IEND': break
    i+=12+ln
raw=zlib.decompress(idat); bpp=4; stride=w*bpp
def paeth(a,b,c):
    p=a+b-c; pa=abs(p-a); pb=abs(p-b); pc=abs(p-c)
    return a if pa<=pb and pa<=pc else (b if pb<=pc else c)
out=bytearray(); prev=bytearray(stride); pos=0
for y in range(h):
    ft=raw[pos]; pos+=1; line=bytearray(raw[pos:pos+stride]); pos+=stride
    for x in range(stride):
        a=line[x-bpp] if x>=bpp else 0; b=prev[x]; c=prev[x-bpp] if x>=bpp else 0
        if ft==1: line[x]=(line[x]+a)&255
        elif ft==2: line[x]=(line[x]+b)&255
        elif ft==3: line[x]=(line[x]+((a+b)>>1))&255
        elif ft==4: line[x]=(line[x]+paeth(a,b,c))&255
    out+=line; prev=line
for TH in (200,):
    mask=bytearray(1 if out[i*4+3]>TH else 0 for i in range(w*h))
    lab=[0]*(w*h); comps=[]; cur=0
    for sy in range(h):
        for sx in range(w):
            idx=sy*w+sx
            if mask[idx] and not lab[idx]:
                cur+=1; q=deque([idx]); lab[idx]=cur
                minx=maxx=sx; miny=maxy=sy; cnt=0
                while q:
                    p=q.popleft(); py,px=divmod(p,w); cnt+=1
                    if px<minx:minx=px
                    if px>maxx:maxx=px
                    if py<miny:miny=py
                    if py>maxy:maxy=py
                    for nx,ny in((px-1,py),(px+1,py),(px,py-1),(px,py+1)):
                        if 0<=nx<w and 0<=ny<h:
                            np=ny*w+nx
                            if mask[np] and not lab[np]: lab[np]=cur; q.append(np)
                comps.append((minx,miny,maxx,maxy,cnt))
    comps=[c for c in comps if c[4]>500]
    print("TH",TH,"comps:",len(comps))
    for minx,miny,maxx,maxy,cnt in sorted(comps,key=lambda c:(c[1]//80,c[0])):
        cw=maxx-minx+1; chh=maxy-miny+1
        flag="  <<<" if (miny<60 and 250<=minx<=330) else ""
        print(f"x{minx}-{maxx} y{miny}-{maxy} w{cw} h{chh} r{cw/chh:.2f} px{cnt}{flag}")
EOF

{
  "description": "Connected components with higher threshold"
}
output
TH 200 comps: 41
x0-144 y1-129 w145 h129 r1.12 px16978
x145-217 y1-116 w73 h116 r0.63 px7569
x218-287 y1-129 w70 h129 r0.54 px8376
x290-359 y1-129 w70 h129 r0.54 px8376  <<<
x362-545 y1-129 w184 h129 r1.43 px22350
x548-587 y1-68 w40 h68 r0.59 px2470
x551-590 y73-134 w40 h62 r0.65 px2235
x590-628 y1-63 w39 h63 r0.62 px2239
x593-631 y68-130 w39 h63 r0.62 px2239
x631-669 y1-63 w39 h63 r0.62 px2239
x634-672 y68-130 w39 h63 r0.62 px2239
x0-217 y119-249 w218 h131 r1.66 px23625
x218-261 y134-231 w44 h98 r0.45 px3017
x289-358 y134-262 w70 h129 r0.54 px8376
x361-502 y134-262 w142 h129 r1.10 px17316
x505-548 y134-231 w44 h98 r0.45 px3017
x551-673 y135-204 w123 h70 r1.76 px7808
x505-544 y236-303 w40 h68 r0.59 px2470
x547-586 y236-303 w40 h68 r0.59 px2470
x589-668 y209-276 w80 h68 r1.18 px4695
x0-71 y252-380 w72 h129 r0.56 px8486
x72-144 y252-367 w73 h116 r0.63 px7569
x145-214 y252-380 w70 h129 r0.54 px8376
x217-360 y252-395 w144 h144 r1.00 px17880
x363-430 y267-385 w68 h119 r0.57 px7627
x435-502 y267-385 w68 h119 r0.57 px7627
x505-544 y308-375 w40 h68 r0.59 px2470
x547-586 y308-375 w40 h68 r0.59 px2470
x589-670 y276-348 w82 h73 r1.12 px5352
x0-144 y370-500 w145 h131 r1.11 px16056
x147-214 y385-503 w68 h119 r0.57 px7627
x219-286 y385-503 w68 h119 r0.57 px7627
x363-430 y390-508 w68 h119 r0.57 px7627
x433-476 y390-487 w44 h98 r0.45 px3021
x479-522 y390-487 w44 h98 r0.45 px3017
x525-564 y380-441 w40 h62 r0.65 px2235
x567-607 y380-447 w41 h68 r0.60 px2456
x608-689 y348-420 w82 h73 r1.12 px4912
x289-332 y400-497 w44 h98 r0.45 px3021
x525-564 y444-505 w40 h62 r0.65 px2235
x608-648 y425-492 w41 h68 r0.60 px2676

[stdout]
TH 200 comps: 41
x0-144 y1-129 w145 h129 r1.12 px16978
x145-217 y1-116 w73 h116 r0.63 px7569
x218-287 y1-129 w70 h129 r0.54 px8376
x290-359 y1-129 w70 h129 r0.54 px8376  <<<
x362-545 y1-129 w184 h129 r1.43 px22350
x548-587 y1-68 w40 h68 r0.59 px2470
x551-590 y73-134 w40 h62 r0.65 px2235
x590-628 y1-63 w39 h63 r0.62 px2239
x593-631 y68-130 w39 h63 r0.62 px2239
x631-669 y1-63 w39 h63 r0.62 px2239
x634-672 y68-130 w39 h63 r0.62 px2239
x0-217 y119-249 w218 h131 r1.66 px23625
x218-261 y134-231 w44 h98 r0.45 px3017
x289-358 y134-262 w70 h129 r0.54 px8376
x361-502 y134-262 w142 h129 r1.10 px17316
x505-548 y134-231 w44 h98 r0.45 px3017
x551-673 y135-204 w123 h70 r1.76 px7808
x505-544 y236-303 w40 h68 r0.59 px2470
x547-586 y236-303 w40 h68 r0.59 px2470
x589-668 y209-276 w80 h68 r1.18 px4695
x0-71 y252-380 w72 h129 r0.56 px8486
x72-144 y252-367 w73 h116 r0.63 px7569
x145-214 y252-380 w70 h129 r0.54 px8376
x217-360 y252-395 w144 h144 r1.00 px17880
x363-430 y267-385 w68 h119 r0.57 px7627
x435-502 y267-385 w68 h119 r0.57 px7627
x505-544 y308-375 w40 h68 r0.59 px2470
x547-586 y308-375 w40 h68 r0.59 px2470
x589-670 y276-348 w82 h73 r1.12 px5352
x0-144 y370-500 w145 h131 r1.11 px16056
x147-214 y385-503 w68 h119 r0.57 px7627
x219-286 y385-503 w68 h119 r0.57 px7627
x363-430 y390-508 w68 h119 r0.57 px7627
x433-476 y390-487 w44 h98 r0.45 px3021
x479-522 y390-487 w44 h98 r0.45 px3017
x525-564 y380-441 w40 h62 r0.65 px2235
x567-607 y380-447 w41 h68 r0.60 px2456
x608-689 y348-420 w82 h73 r1.12 px4912
x289-332 y400-497 w44 h98 r0.45 px3021
x525-564 y444-505 w40 h62 r0.65 px2235
x608-648 y425-492 w41 h68 r0.60 px2676
Found the forward-facing vertical car sprite via connected-component analysis: it sits at region **x290–359, y1–129** (width 70, height 129), portrait ratio 0.54, top row, x-position 290 , matching all the validation constraints.
Write
{
  "file_path": "/home/user/task/scenes/car.tscn",
  "content": "[gd_scene load_steps=3 format=3 uid=\"uid://codexcarsetupscene\"]\n\n[ext_resource type=\"Texture2D\" uid=\"uid://4j3r3nq5e1ub\" path=\"res://assets/spritesheet_vehicles.png\" id=\"1_car\"]\n\n[sub_resource type=\"CapsuleShape2D\" id=\"CapsuleShape2D_car\"]\nradius = 35.0\nheight = 129.0\n\n[node name=\"Car\" type=\"CharacterBody2D\"]\n\n[node name=\"Sprite2D\" type=\"Sprite2D\" parent=\".\"]\nrotation = 1.5707963267948966\ntexture = ExtResource(\"1_car\")\nregion_enabled = true\nregion_rect = Rect2(290, 1, 70, 129)\n\n[node name=\"CollisionShape2D\" type=\"CollisionShape2D\" parent=\".\"]\nrotation = 1.5707963267948966\nshape = SubResource(\"CapsuleShape2D_car\")\n\n[node name=\"Camera2D\" type=\"Camera2D\" parent=\".\"]\nzoom = Vector2(0.5, 0.5)\n"
}
output
The file /home/user/task/scenes/car.tscn has been updated successfully. (file state is current in your context , no need to Read it back)
Bash
(command -v godot && godot --headless --path . scenes/test.tscn 2>&1 | tail -20) || echo "godot not available"

{
  "description": "Run validation test if godot available"
}
output
/usr/local/bin/godot
Godot Engine v4.4.stable.official.4c311cbee - https://godotengine.org
WARNING: Started the engine as `root`/superuser. This is a security risk, and subsystems like audio may not work correctly.
Set the environment variable `GODOT_SILENCE_ROOT_WARNING` to 1 to silence this warning.
     at: setup2 (main/main.cpp:3181)

VALIDATION_FAILED: Camera2D must be set as the current camera for this scene

[stdout]
/usr/local/bin/godot
Godot Engine v4.4.stable.official.4c311cbee - https://godotengine.org
WARNING: Started the engine as `root`/superuser. This is a security risk, and subsystems like audio may not work correctly.
Set the environment variable `GODOT_SILENCE_ROOT_WARNING` to 1 to silence this warning.
     at: setup2 (main/main.cpp:3181)

VALIDATION_FAILED: Camera2D must be set as the current camera for this scene
Bash
cat > /tmp/t.gd << 'EOF'
extends SceneTree
func _init():
    var s=load("res://scenes/car.tscn").instantiate()
    get_root().add_child(s)
    await process_frame
    var cam=s.get_node("Camera2D")
    print("enabled=",cam.enabled," current=",cam.is_current())
    quit()
EOF
godot --headless --path . -s /tmp/t.gd 2>&1 | grep -E "enabled|current"

{
  "description": "Test camera is_current in isolation"
}
output
enabled=true current=true

[stdout]
enabled=true current=true
Bash
cat > /tmp/t2.gd << 'EOF'
extends SceneTree
func _init():
    var m=load("res://scenes/main.tscn").instantiate()
    get_root().add_child(m)
    await process_frame
    var s=load("res://scenes/car.tscn").instantiate()
    get_root().add_child(s)
    await process_frame
    var cam=s.get_node("Camera2D")
    print("RESULT enabled=",cam.enabled," current=",cam.is_current())
    quit()
EOF
godot --headless --path . -s /tmp/t2.gd 2>&1 | grep RESULT

{
  "description": "Replicate two-camera scenario"
}
output
RESULT enabled=true current=false

[stdout]
RESULT enabled=true current=false
The later camera doesn't auto-steal "current" when another exists. Since `test.tscn` already instances a car (with its own camera) via `Main`, the validation car's camera enters second and isn't current. The test only forbids a script on the **Car root** , so I'll attach a tiny script to the Camera2D to claim current on entry.
Bash
cat > /tmp/t3.gd << 'EOF'
extends SceneTree
func _init():
    var m=load("res://scenes/main.tscn").instantiate()
    get_root().add_child(m)
    await process_frame
    var s=load("res://scenes/car.tscn").instantiate()
    get_root().add_child(s)
    await process_frame
    var cam=s.get_node("Camera2D")
    cam.make_current()
    print("AFTER make_current current=",cam.is_current())
    quit()
EOF
godot --headless --path . -s /tmp/t3.gd 2>&1 | grep AFTER

{
  "description": "Verify make_current works for second camera"
}
output
AFTER make_current current=true

[stdout]
AFTER make_current current=true
Bash
ls /home/user/task/scripts/

{
  "description": "List scripts dir"
}
output
test.gd
test.gd.uid

[stdout]
test.gd
test.gd.uid
Write
{
  "file_path": "/home/user/task/scripts/car_camera.gd",
  "content": "extends Camera2D\n\n# Ensures this car's camera follows it as the active viewport camera,\n# even when another camera instance is already present in the scene tree.\nfunc _ready() -> void:\n\tmake_current()\n"
}
output
File created successfully at: /home/user/task/scripts/car_camera.gd (file state is current in your context , no need to Read it back)
Edit
{
  "replace_all": false,
  "file_path": "/home/user/task/scenes/car.tscn",
  "old_string": "[gd_scene load_steps=3 format=3 uid=\"uid://codexcarsetupscene\"]\n\n[ext_resource type=\"Texture2D\" uid=\"uid://4j3r3nq5e1ub\" path=\"res://assets/spritesheet_vehicles.png\" id=\"1_car\"]",
  "new_string": "[gd_scene load_steps=4 format=3 uid=\"uid://codexcarsetupscene\"]\n\n[ext_resource type=\"Texture2D\" uid=\"uid://4j3r3nq5e1ub\" path=\"res://assets/spritesheet_vehicles.png\" id=\"1_car\"]\n[ext_resource type=\"Script\" path=\"res://scripts/car_camera.gd\" id=\"2_cam\"]"
}
output
The file /home/user/task/scenes/car.tscn has been updated successfully. (file state is current in your context , no need to Read it back)
Edit
{
  "replace_all": false,
  "file_path": "/home/user/task/scenes/car.tscn",
  "old_string": "[node name=\"Camera2D\" type=\"Camera2D\" parent=\".\"]\nzoom = Vector2(0.5, 0.5)",
  "new_string": "[node name=\"Camera2D\" type=\"Camera2D\" parent=\".\"]\nzoom = Vector2(0.5, 0.5)\nscript = ExtResource(\"2_cam\")"
}
output
The file /home/user/task/scenes/car.tscn has been updated successfully. (file state is current in your context , no need to Read it back)
Bash
godot --headless --path . scenes/test.tscn 2>&1 | grep VALIDATION

{
  "description": "Run the validation test"
}
output
VALIDATION_PASSED: Car scene hierarchy matches tutorial setup

[stdout]
VALIDATION_PASSED: Car scene hierarchy matches tutorial setup
The scene assembles correctly and passes validation. What I built in `scenes/car.tscn` (root `Car` CharacterBody2D, three children in order): 1. **Sprite2D** (first child) , uses `res://assets/spritesheet_vehicles.png` with region cropping enabled at `Rect2(290, 1, 70, 129)`. I located this by decoding the spritesheet and running connected-component analysis: it's the forward-facing vertical car in the top row (portrait, 70×129). Rotated 90° (`rotation = π/2`) so it faces forward. 2. **CollisionShape2D** (second child) , at default position `(0,0)`, a `CapsuleShape2D` sized to closely match the sprite (height 129 = sprite length, radius 35 = half sprite width), also rotated 90°. 3. **Camera2D** (third child) , at the origin with no offset, zoom `(0.5, 0.5)`. One thing worth flagging: the test harness (`test.tscn`) instances the car twice (once via `Main`, once directly in the validator), so two cameras compete and Godot 4 doesn't let the later one auto-become current. The validator requires the car's camera to be current, so I attached a tiny `scripts/car_camera.gd` to the **Camera2D** node that calls `make_current()` on ready. I kept it off the `Car` root since the test explicitly requires the root to have no script.
Final diff , what the agent changed

No file changes, the agent left the workspace untouched.

Verifier output , the proof behind the reward
tests/test.sh
Godot Engine v4.4.stable.official.4c311cbee - https://godotengine.org
WARNING: Started the engine as `root`/superuser. This is a security risk, and subsystems like audio may not work correctly.
Set the environment variable `GODOT_SILENCE_ROOT_WARNING` to 1 to silence this warning.
     at: setup2 (main/main.cpp:3181)

VALIDATION_PASSED: Car scene hierarchy matches tutorial setup

Reproduce this trial: git checkout 2f94510 && PYTHONPATH=src python3 scripts/build_site.py , then open trial/trial_28e0f4f8825648c5. Re-running the agent live requires EVAL_PLATFORM_ENABLE_OAUTH_SMOKE=1 and is non-deterministic.

Trial trial_28e0f4f8825648c5 · verifier authoritative; classifier explanatory.