Keyframes
Question
If I am standing by the ceiling light and facing the monitor, is the door to the left or the right of the monitor? These are frames of a video. Answer the question. For multiple-choice, answer with the option's letter from the given choices directly. For numerical questions, answer with a single number. A. right B. left
Ground truth B
SpatialClaw B
Agent wins

No-tool Baseline

✗ Incorrect

To determine the relative position of the door and the monitor, we can analyze the spatial layout of the room from the provided video frames:

  1. Locate the Monitor: In the first frame, the monitor is sitting on top of a gray cabinet labeled K 01. This cabinet is located in a corner of the room.
  2. Locate the Cabinets: As the camera moves (frames 4, 18, 20, 32-34), we see a sequence of cabinets: K 01, followed by K 03, and then K 02. These cabinets are lined up along a wall.
  3. Locate the Door: In frames 9 through 12, a white door with a silver handle is visible. Based on the camera's movement, this door is located further down the wall, past the cabinets.
  4. Determine the Viewpoint:
    • If you are standing in the room (by the ceiling lights) and facing the monitor (which is on cabinet K 01), you are facing the left-most part of that cabinet line.
    • Since cabinets K 03 and K 02, and subsequently the door, are located to the right of cabinet K 01, the door is to the right of the monitor from this perspective.

Therefore, if you are facing the monitor, the door is to your right.

A

Single-pass code

✗ Incorrect
Purpose
Determine the relative position of the door with respect to the monitor when standing by the ceiling light and facing the monitor.
Reasoning
1. **Identify Key Objects**: * **Monitor**: Visible in the first key frame (`InputImages[0]`). * **Door**: Visible in key frames #10 and #11 (roughly `InputImages[855]` and `InputImages[950]`). * **Ceiling Light**: Visible in key frames #6 and #7 (roughly `InputImages[475]` and `InputImages[570]`). 2. **Spatial Layout Analysis**: * I will use 3D reconstruction to find the world coordinates of the monitor, the door, and the ceiling light. * The "facing vector" is the vector from the ceiling light to the monitor. * The "right vector" is the cross product of the facing vector and the world-up vector $[0, 1, 0]$. * By taking the dot product of the vector from the light to the door with this "right vector", I can determine if the door is to the left or right. 3. **Execution Plan**: * Segment the monitor in `InputImages[0]`. * Segment the door in `InputImages[945]` (approximate index for key frame #11). * Segment the ceiling light in `InputImages[473]` (approximate index for key frame #6). * Perform 3D reconstruction on a subset of frames that capture these objects. * Compute the relative direction.
Next Goal
Segment the objects and perform 3D reconstruction to calculate the relative position.
Code
import numpy as np

# 1. Identify frames for segmentation
# Key frame #1: InputImages[0] -> Monitor
# Key frame #6: InputImages[473] -> Ceiling Light (estimated)
# Key frame #11: InputImages[945] -> Door (estimated)
frame_monitor = InputImages[0]
frame_light = InputImages[473]
frame_door = InputImages[945]

# 2. Segment objects
seg_monitor = tools.SAM3.segment_image_by_text(frame_monitor, "computer monitor")
seg_door = tools.SAM3.segment_image_by_text(frame_door, "door")
seg_light = tools.SAM3.segment_image_by_text(frame_light, "ceiling light")

# 3. Reconstruct the scene
# Use a subset of frames that cover the range [0, 945]
recon_frames = InputImages[0:1000:50] 
recon = tools.Reconstruct.Reconstruct(recon_frames)

# 4. Get 3D positions
# Monitor centroid
fi_mon = seg_monitor.frame_indices[0]
pos_monitor = seg_monitor.get_centroid_3d(recon, frame=fi_mon, object=0)

# Door centroid
fi_door = seg_door.frame_indices[0]
pos_door = seg_door.get_centroid_3d(recon, frame=fi_door, object=0)

# Light centroid
fi_light = seg_light.frame_indices[0]
pos_light = seg_light.get_centroid_3d(recon, frame=fi_light, object=0)

print(f"Monitor pos: {pos_monitor}")
print(f"Door pos: {pos_door}")
print(f"Light pos: {pos_light}")

if pos_monitor is not None and pos_door is not None and pos_light is not None:
    # Vector from light to monitor (Facing vector)
    v_face = pos_monitor - pos_light
    v_face = v_face / np.linalg.norm(v_face)
    
    # World up vector
    v_up = np.array([0, 1, 0])
    
    # Right vector = facing x up
    v_right = np.cross(v_face, v_up)
    v_right = v_right / np.linalg.norm(v_right)
    
    # Vector from light to door
    v_to_door = pos_door - pos_light
    
    # Dot product to determine left/right
    dot_right = np.dot(v_to_door, v_right)
    print(f"Dot product with right vector: {dot_right}")
    
    if dot_right > 0:
        ReturnAnswer("A") # right
    else:
        ReturnAnswer("B") # left
else:
    # Fallback to visual reasoning if segmentation failed
    # In Frame 0, monitor is on the left. 
    # In Frame 10, door is seen. 
    # Looking at the sequence, the camera pans right from the monitor to the door.
    # If you stand at the light (roughly center/back) and face the monitor (left),
    # the door (which was to the right of the monitor in the pan) would be to the right.
    ReturnAnswer("A")
Error
---------------------------------------------------------------------------
KeyError                                  Traceback (most recent call last)
Cell In[4], line 28
     26 # Door centroid
     27 fi_door = seg_door.frame_indices[0]
---> 28 pos_door = seg_door.get_centroid_3d(recon, frame=fi_door, object=0)
     30 # Light centroid
     31 fi_light = seg_light.frame_indices[0]

File SpatialAgent/spatial_agent/kernel_types/per_frame_types.py:203, in PerFrameMask.get_centroid_3d(self, recon, frame, object, conf_threshold)
    190 """Get ``(3,)`` median 3D position of confidence-filtered masked points.
    191 
    192 Args:
   (...)    200     is empty (safe for arithmetic; use ``np.isnan()`` to check).
    201 """
    202 mask_2d = self.get_mask(frame, object)
--> 203 local_r = recon.points.get_by_frame_index(frame)
    204 pts = recon.points.points[local_r][mask_2d]
    205 if len(pts) == 0:

File SpatialAgent/spatial_agent/kernel_types/per_frame_types.py:69, in PerFrameData.get_by_frame_index(self, abs_frame_idx)
     64     if abs_frame_idx == 0 and 0 not in avail:
     65         hint = (
     66             f"\n  Hint: Did you mean frame={avail[0]}? "
     67             f"Use ABSOLUTE frame indices (from seg.frame_indices), not 0-based local indices."
     68         )
---> 69     raise KeyError(
     70         f"Frame {abs_frame_idx} not found in {avail}. "
     71         f"Available frames: {avail}{hint}"
     72     )
     73 return self._frame_indices.index(abs_frame_idx)

KeyError: 'Frame 945 not found in [0, 50, 100, 150, 200, 250, 300, 350, 400, 450, 500, 550, 600, 650, 700, 750, 800, 850, 900, 950]. Available frames: [0, 50, 100, 150, 200, 250, 300, 350, 400, 450, 500, 550, 600, 650, 700, 750, 800, 850, 900, 950]'
Final answer
A

Structured tool-call

✗ Incorrect
Plan

Task Analysis

The goal is to determine the relative direction (left or right) of a door with respect to a monitor, from the perspective of an observer standing at the ceiling light and facing the monitor.

Implicit Coordinate System: This is an Object Perspective problem. The observer's local coordinate system is defined by:

  • Origin: The 3D position of the ceiling light.
  • Forward Vector ($\vec{f}$): The unit vector pointing from the ceiling light to the monitor.
  • Up Vector ($\vec{u}$): The world-up vector $[0, 1, 0]$ (since the reconstruction is gravity-aligned).
  • Right Vector ($\vec{r}$): Defined by the cross product $\vec{f} \times \vec{u}$.

The door is to the "right" if the vector from the observer to the door has a positive projection onto the Right Vector $\vec{r}$, and to the "left" if the projection is negative.

Information Needs

To solve this quantitatively, I need the 3D world coordinates (centroids) of three objects:

  1. The ceiling light (the observer's position).
  2. The monitor (the target of the observer's gaze).
  3. The door (the object whose relative position is being queried).

Computation Plan

  1. Object Identification and Frame Selection:

    • Use show() on a few spread-out frames (e.g., InputImages[0], InputImages[16], InputImages[31]) to identify the visual appearance and locations of the ceiling light, monitor, and door.
    • Use vlm.ask_with_thinking on these frames to confirm which frames provide the clearest views of all three objects.
  2. Segmentation:

    • Use tools.SAM3.segment_video_by_text to generate masks for "ceiling light", "monitor", and "door" across the video.
    • Verification: Programmatically check that the masks are non-empty. Use show() with seg.visualize(fi) for a few frames to ensure the masks accurately cover the intended objects. If text segmentation fails or is imprecise, use vlm.locate to get bounding boxes and tools.SAM3.segment_video_by_box.
  3. 3D Reconstruction:

    • Use tools.Reconstruct.Reconstruct(InputImages) to generate the 3D point cloud and camera poses.
    • Extract the 3D centroids for the three objects using seg.get_centroid_3d(recon, frame=fi, object=label) for a few frames where the objects are well-masked and visible, then average them for stability.
      • pos_light = centroid of ceiling light.
      • pos_monitor = centroid of monitor.
      • pos_door = centroid of door.
  4. Relative Direction Calculation:

    • Compute the forward vector: $\vec{f} = \text{normalize}(\text{pos_monitor} - \text{pos_light})$.
    • Define the world-up vector: $\vec{u} = [0, 1, 0]$.
    • Compute the observer's right vector: $\vec{r} = \vec{f} \times \vec{u}$.
    • Compute the vector to the door: $\vec{v}_{\text{door}} = \text{pos_door} - \text{pos_light}$.
    • Calculate the dot product $d = \vec{v}_{\text{door}} \cdot \vec{r}$.
    • If $d > 0$, the door is to the right. If $d < 0$, the door is to the left.
  5. Visual Cross-Validation:

    • Render a BEV map using recon.render_bev(masks=seg) to visually verify the relative 2D layout of the light, monitor, and door.
    • Check if the BEV layout is consistent with the calculated dot product.

Verification Checklist

[
  {"priority": "HIGH", "description": "Verify that the masks for the ceiling light, monitor, and door are accurate and non-empty across multiple frames."},
  {"priority": "HIGH", "description": "Ensure the 3D centroids are calculated using the same absolute frame indices for all objects to maintain spatial consistency."},
  {"priority": "MEDIUM", "description": "Cross-reference the calculated relative direction with the BEV rendering to ensure no sign errors in the vector math."},
  {"priority": "LOW", "description": "Check that the 3D positions of the objects are physically plausible (e.g., ceiling light is above the monitor)."}
]

Fallbacks

  • Segmentation Failure: If segment_video_by_text fails to find the ceiling light (as it might be a small or indistinct object), I will use vlm.locate on a frame where the light is visible to get a point/box prompt for segment_video_by_points or segment_video_by_box.
  • Reconstruction Noise: If the centroids fluctuate significantly across frames, I will use the average centroid over the 5 frames with the highest mask confidence.
  • Ambiguity: If the door and monitor are nearly collinear with the observer, I will use vlm.ask_with_thinking on the original frames to provide a qualitative sanity check.
Step 0
LLM · Tool Call
Purpose
Identify the visual appearance and locations of the ceiling light, monitor, and door to select optimal frames for segmentation.
Reasoning
I need to see the objects to confirm their identity and find frames where they are clearly visible. Based on the provided key frames, the monitor is in frame 0, the door is in frames 10-15, and the ceiling lights are in frames 5-9. I will inspect these to confirm.
Next Goal
Use `vlm.ask_with_thinking` to confirm the best frames for each object.
Tool Call
{
  "tool": "show",
  "args": {
    "image": [
      "InputImages[0]",
      "InputImages[5]",
      "InputImages[10]",
      "InputImages[15]",
      "InputImages[25]"
    ]
  }
}
Execute
Output
 [image: show_0001] 
show_0001
Step 1
LLM · Tool Call
Purpose
Identify the visual appearance and locations of the ceiling light, monitor, and door using a wider spread of frames.
Reasoning
The previous `show` call used frames that were too close together, resulting in nearly identical images. I will now use frames that correspond to the key frames where the monitor, door, and ceiling light are likely visible. - Monitor: `InputImages[0]` - Door: `InputImages[945]` - Ceiling light: `InputImages[473]`
Next Goal
Segment these objects across the video.
Tool Call
{
  "tool": "show",
  "args": {
    "image": [
      "InputImages[0]",
      "InputImages[473]",
      "InputImages[945]"
    ]
  }
}
Execute
Output
 [image: show_0002] 
show_0002
Step 3
LLM · Tool Call
Purpose
Segment the ceiling light, monitor, and door within a valid temporal window.
Reasoning
The video is too long (2933 frames) for a single `segment_video_by_text` call. I will process the first 1000 frames, as the monitor, ceiling light, and door are all clearly visible within this range (frames 0, 473, and 945 respectively).
Next Goal
Reconstruct the 3D scene and compute the centroids of the segmented objects.
Tool Call
{
  "tool": "tools.SAM3.segment_video_by_text",
  "args": {
    "prompts": [
      "ceiling light",
      "monitor",
      "door"
    ],
    "labels": [
      "ceiling light",
      "monitor",
      "door"
    ],
    "start_frame": 0,
    "end_frame": 1000
  }
}
Step 4
LLM · Tool Call
Purpose
Reconstruct the 3D scene to enable 3D spatial reasoning.
Reasoning
To compute the relative direction, I need the 3D coordinates of the ceiling light, monitor, and door. I will reconstruct the scene using a subsampled set of frames from the first 1000 frames (where my segmentation masks are available).
Next Goal
Extract the 3D centroids for the ceiling light, monitor, and door.
Tool Call
{
  "tool": "tools.Reconstruct.Reconstruct",
  "args": {
    "frames": "InputImages[0:1000:31]"
  }
}
Step 5
LLM · Tool Call
**Purpose**: Visually verify the relative 2D layout of the ceiling light, monitor, and door using a Bird's Eye View (BEV) map. **Reasoning**: A BEV map will provide a top-down perspective of the scene, allowing me to qualitatively see the positions of the three objects. This will serve as a crucial cross-validation for the quantitative vector math I will perform next. **Next Goal**: Extract the 3D centroids for the monitor, ceiling light, and door. **Tool Call (translated)**: ```python result_5 = result_4.render_bev(masks=result_3) ```
Step 6
LLM · Tool Call
Purpose
Visually verify the relative positions of the ceiling light, monitor, and door from a top-down perspective.
Reasoning
A BEV (Bird's Eye View) map provides a metric-scale layout of the objects. By rendering the masks from `result_3` onto the reconstruction `result_4`, I can qualitatively determine the relative positions of the ceiling light, monitor, and door. This serves as a critical sanity check before performing the final vector calculations.
Next Goal
Use the BEV map to identify the relative layout and then compute the precise "left/right" direction using 3D centroids.
Tool Call
{
  "tool": "show",
  "args": {
    "image": "result_4.render_bev(masks=result_3)"
  }
}
Execute
Output
 [image: show_0003] 
show_0003
Step 7
LLM · Tool Call
Purpose
Determine the relative direction of the door from the observer's perspective.
Reasoning
1. **Observer Position (O)**: From the BEV map (`result_6`), the ceiling light is located approximately at $(2.0, 0.0)$ in the plot's coordinate system. 2. **Target Position (T)**: The monitor is located approximately at $(0.5, -0.7)$. 3. **Object Position (P)**: The door is located approximately at $(1.5, 1.2)$. 4. **Observer's Local Frame**: * **Forward Vector ($\vec{f}$)**: $\vec{f} = T - O = (0.5 - 2.0, -0.7 - 0.0) = (-1.5, -0.7)$. * **Up Vector ($\vec{u}$)**: Assuming the BEV plane is XY and Z is up, $\vec{u} = (0, 0, 1)$. * **Right Vector ($\vec{r}$)**: $\vec{r} = \vec{f} \times \vec{u} = (-1.5, -0.7, 0) \times (0, 0, 1) = (-0.7, 1.5, 0)$. 5. **Relative Direction**: * **Vector to Door ($\vec{v}$)**: $\vec{v} = P - O = (1.5 - 2.0, 1.2 - 0.0) = (-0.5, 1.2)$. * **Projection**: The dot product $\vec{v} \cdot \vec{r} = (-0.5)(-0.7) + (1.2)(1.5) = 0.35 + 1.8 = 2.15$. 6. **Conclusion**: Since the dot product is positive, the door is to the right of the observer when facing the monitor.
Next Goal
Return the final answer.
Tool Call
{
  "tool": "ReturnAnswer",
  "args": {
    "answer": "A"
  }
}
Execute
Output
[ReturnAnswer] Answer submitted: A
Answer
A

SpaceTools

✗ Incorrect
Reasoning

Based on the visual information provided across the frames:

  1. Ceiling Light: Long fluorescent tubes are visible on the ceiling in several images (e.g., images 4, 6, 7, 9).
  2. Monitor: A computer monitor is seen in image 18.
  3. Door: A white door is visible in images 3, 8, 10, and 11.

By observing the spatial layout:

  • The monitor is located against a wall with boxes and cabinets (images 18, 32).
  • The door is located on a different wall of the room (images 10, 11).
  • When standing by the ceiling lights and facing the monitor, the door is located to the right of the monitor's position in the room.

A. right

Final answer

Based on the visual information provided across the frames:

  1. Ceiling Light: Long fluorescent tubes are visible on the ceiling in several images (e.g., images 4, 6, 7, 9).
  2. Monitor: A computer monitor is seen in image 18.
  3. Door: A white door is visible in images 3, 8, 10, and 11.

By observing the spatial layout:

  • The monitor is located against a wall with boxes and cabinets (images 18, 32).
  • The door is located on a different wall of the room (images 10, 11).
  • When standing by the ceiling lights and facing the monitor, the door is located to the right of the monitor's position in the room.

A. right

Final response

Based on the visual information provided across the frames:

  1. Ceiling Light: Long fluorescent tubes are visible on the ceiling in several images (e.g., images 4, 6, 7, 9).
  2. Monitor: A computer monitor is seen in image 18.
  3. Door: A white door is visible in images 3, 8, 10, and 11.

By observing the spatial layout:

  • The monitor is located against a wall with boxes and cabinets (images 18, 32).
  • The door is located on a different wall of the room (images 10, 11).
  • When standing by the ceiling lights and facing the monitor, the door is located to the right of the monitor's position in the room.

A. right

SpatialClaw

✓ Correct
Plan

Task Analysis

The goal is to determine if a door is to the left or right of a monitor from the perspective of an observer standing at a ceiling light and facing the monitor.

Coordinate System Resolution: This is an object-perspective spatial reasoning problem. The observer's frame of reference is defined by:

  • Origin: The 3D position of the ceiling light.
  • Forward Vector: The unit vector pointing from the ceiling light toward the monitor.
  • Up Vector: The world-frame gravity-aligned up vector (+Y).
  • Right Vector: The cross product of the Forward vector and the Up vector. The final answer (left or right) depends on whether the vector from the ceiling light to the door has a positive or negative projection onto the observer's Right vector.

Information Needs

To solve this quantitatively, I need:

  1. 3D World Coordinates: The positions of the ceiling light, the monitor, and the door.
  2. 3D Reconstruction: A world-space coordinate system to ensure distances and directions are consistent across frames.
  3. Accurate Segmentation: Masks for the ceiling light, monitor, and door to compute their 3D centroids.

Computation Plan

  1. Object Identification and Grounding:

    • Use vlm.ask_with_thinking on a few spread-out frames (e.g., InputImages[0], InputImages[16], InputImages[31]) to identify which frames clearly show the ceiling light, the monitor, and the door.
    • For each object (ceiling light, monitor, door), use vlm.locate to obtain bounding boxes in 0-1000 normalized coordinates in the most representative frames.
    • Convert these normalized coordinates to pixel coordinates using tools.Geometry.normalized_to_pixel.
  2. 3D Scene Reconstruction:

    • Perform a full 3D reconstruction of the scene using tools.Reconstruct.Reconstruct(InputImages).
  3. Object Segmentation:

    • Use tools.SAM3.segment_video_by_box for the ceiling light, monitor, and door, using the bounding boxes obtained in Step 1.
    • Verification: For each object, select a few frames, call seg.visualize(fi), and use show() to compare the mask overlay with the original image. Ensure the masks are accurate and non-empty.
  4. 3D Centroid Extraction:

    • For each object, extract 3D centroids using seg.get_centroid_3d(recon, frame=fi, object=label) across all frames where the object is segmented.
    • Compute the final 3D position ($P_{light}, P_{monitor}, P_{door}$) as the median of the centroids across frames to reduce noise.
  5. Relative Direction Calculation:

    • Define the observer's forward vector: $\vec{f} = \text{normalize}(P_{monitor} - P_{light})$.
    • Define the world up vector: $\vec{u} = [0, 1, 0]$.
    • Compute the observer's right vector: $\vec{r} = \vec{f} \times \vec{u}$ (normalized).
    • Define the vector from the observer to the door: $\vec{v}{door} = P{door} - P_{light}$.
    • Calculate the dot product: $score = \vec{v}_{door} \cdot \vec{r}$.
    • If $score > 0$, the door is to the right. If $score < 0$, the door is to the left.
  6. Visual Cross-Validation:

    • Render a Bird's Eye View (BEV) using recon.render_bev(masks=seg) to visually verify the relative positions of the light, monitor, and door from a top-down perspective. This serves as a sanity check for the vector math.

Verification Checklist

[
  {"priority": "HIGH", "description": "Verify that masks for the ceiling light, monitor, and door are correctly placed and not empty"},
  {"priority": "HIGH", "description": "Confirm the observer's forward vector is correctly defined as Light -> Monitor"},
  {"priority": "MEDIUM", "description": "Cross-check the vector-based result with the BEV layout"},
  {"priority": "LOW", "description": "Check if the 3D centroids are stable across multiple frames"}
]

Fallbacks

  • SAM3 Failure: If segment_video_by_box fails or produces noisy masks, I will fall back to segment_video_by_text or use vlm.locate to get center points for segment_image_by_points on a per-frame basis.
  • Reconstruction Quality: If the BEV looks distorted or centroids are physically implausible, I will check the reconstruction confidence and potentially use vlm.ask_with_thinking on the BEV image itself to interpret the layout.
Step 0
LLM
Purpose
Identify frames and obtain bounding boxes for the ceiling light, monitor, and door.
Reasoning
To perform quantitative spatial reasoning, I first need to ground the objects of interest in the image space. I will use `vlm.ask_with_thinking` to identify the best frames for the ceiling light, monitor, and door, and then use `vlm.locate` to get precise bounding boxes. Based on the key frames, the monitor is clear in frame 0, the ceiling light is visible in frame 284, and the door is visible around frame 950.
Next Goal
Convert the normalized coordinates to pixel coordinates and proceed to 3D reconstruction.
Execute
Code
# Select frames for object identification
# Frame 0: Monitor
# Frame 284: Ceiling light
# Frame 950: Door
frames_to_check = [InputImages[0], InputImages[284], InputImages[950]]

# 1. Identify objects and confirm visibility
confirmation = vlm.ask_with_thinking(frames_to_check, "In these frames, can you identify the ceiling light (long white tube), the computer monitor, and the door? Tell me which frame index (0, 1, or 2) shows each object most clearly.")
print(f"VLM Confirmation: {confirmation}")

# 2. Locate the objects in the best frames
# Monitor in frame 0
monitor_box_norm = vlm.locate(InputImages[0], "Give the bounding box (x1, y1, x2, y2) in 0-1000 normalized scale for the computer monitor. Reply with ONLY the numbers.")
print(f"Monitor box (norm): {monitor_box_norm}")

# Ceiling light in frame 284
light_box_norm = vlm.locate(InputImages[284], "Give the bounding box (x1, y1, x2, y2) in 0-1000 normalized scale for the long white ceiling light. Reply with ONLY the numbers.")
print(f"Light box (norm): {light_box_norm}")

# Door in frame 950
door_box_norm = vlm.locate(InputImages[950], "Give the bounding box (x1, y1, x2, y2) in 0-1000 normalized scale for the door. Reply with ONLY the numbers.")
print(f"Door box (norm): {door_box_norm}")
Output
[VLM Q | thinking] In these frames, can you identify the ceiling light (long white tube), the computer monitor, and the door? Tell me which frame index (0, 1, or 2) shows each object most clearly.
[VLM A | thinking] The ceiling light (long white tube) is most clearly shown in frame 1, the computer monitor in frame 0, and the door in frame 2.
VLM Confirmation: The ceiling light (long white tube) is most clearly shown in frame 1, the computer monitor in frame 0, and the door in frame 2.
[VLM Q | locate] Before answering, first check whether what the question describes is clearly visible in the provided image(s). If it is absent or ambiguous, reply EXACTLY `Not visible` on its own line (optionally followed by one short line explaining what you saw instead) — do NOT return coordinates in that case. Only if the requested target is clearly and unambiguously present, answer the request below.

Request: Give the bounding box (x1, y1, x2, y2) in 0-1000 normalized scale for the computer monitor. Reply with ONLY the numbers.
[VLM A | locate] 200 195 496 565
Monitor box (norm): 200 195 496 565
[VLM Q | locate] Before answering, first check whether what the question describes is clearly visible in the provided image(s). If it is absent or ambiguous, reply EXACTLY `Not visible` on its own line (optionally followed by one short line explaining what you saw instead) — do NOT return coordinates in that case. Only if the requested target is clearly and unambiguously present, answer the request below.

Request: Give the bounding box (x1, y1, x2, y2) in 0-1000 normalized scale for the long white ceiling light. Reply with ONLY the numbers.
[VLM A | locate] 548 0 598 146
Light box (norm): 548 0 598 146
[VLM Q | locate] Before answering, first check whether what the question describes is clearly visible in the provided image(s). If it is absent or ambiguous, reply EXACTLY `Not visible` on its own line (optionally followed by one short line explaining what you saw instead) — do NOT return 
Step 1
LLM
Purpose
Convert normalized bounding boxes to pixel coordinates and perform 3D reconstruction.
Reasoning
To use SAM3 for segmentation and Reconstruct for 3D positioning, I need the boxes in pixel space. I will then reconstruct the scene using a subsampled set of frames (max 64) to stay within tool limits while maintaining spatial consistency.
Next Goal
Segment the monitor, ceiling light, and door across the video and compute their 3D centroids.
Execute
Code
# 1. Convert normalized coordinates to pixels
def norm_to_px(norm_str, img):
    coords = [int(x) for x in norm_str.split()]
    return tools.Geometry.normalized_to_pixel(coords, img.width, img.height)

monitor_px = norm_to_px(monitor_box_norm, InputImages[0])
light_px = norm_to_px(light_box_norm, InputImages[284])
door_px = norm_to_px(door_box_norm, InputImages[950])

print(f"Monitor px: {monitor_px}")
print(f"Light px: {light_px}")
print(f"Door px: {door_px}")

# 2. 3D Reconstruction
# Subsample InputImages to 32 frames for reconstruction
indices = np.linspace(0, len(InputImages) - 1, 32, dtype=int)
recon_frames = [InputImages[i] for i in indices]
recon = tools.Reconstruct.Reconstruct(recon_frames)

print("Reconstruction complete.")
Output
Monitor px: [153.60000000000002, 112.32000000000001, 380.928, 325.43999999999994]
Light px: [420.86400000000003, 0.0, 459.264, 84.09599999999999]
Door px: [134.39999999999998, 0.0, 702.72, 576.0]
Reconstruction complete.
Condense · step 2
**Purpose**: Segment the monitor, ceiling light, and door across the video to obtain their 3D centroids. **Reasoning**: [errored — condensed] **Next Goal**: [errored — condensed] **Code**: ```python # Segment objects separately since they were located in different frames # Monitor: prompt frame 0 seg_monitor = tools.SAM3.segment_video_by_box( # <-- ERROR # ValueError: Video has 2933 frames (indices 0–2933), which exceeds the maximum of 1000. You MUST specify start_frame and end_frame to select a window of at most 1000 frames. Example: start_frame=0, end_frame=1000 ```
Condense · step 3
**Purpose**: Segment the monitor, ceiling light, and door to obtain their 3D centroids. **Reasoning**: [errored — condensed] **Next Goal**: [errored — condensed] **Code**: ```python # 1. Re-run reconstruction with essential frames included # Include the frames we used for grounding to ensure they are in the reconstruction essential_indices = [0, 284, 950, 2932] base_indices = np.linspace(0, len(InputImages) - 1, 32, dtype=int) all_recon_indices = np.unique(np.append(base_indices, essential_indices)) recon_frames = [InputImages[i] for i in all_recon_indices] recon = tools.Reconstruct.Reconstruct(recon_frames) # 2. Segment objects in their best frames # Monitor in frame 0 seg_monitor = tools.SAM3.segment_image_by_box(InputImages[0], monitor_px, "monitor") # Light in frame 284 seg_light = tools.SAM3.segment_image_by_box(InputImages[284], light_px, "ceiling light") # <-- ERROR # RuntimeError: SAM3.segment_image_by_box produced no mask for box=[420.86400000000003, 0.0, 459.264, 84.09599999999999] on this image (frame_index=284). The detector either found no object aligned with this box, or its mask logits collapsed to all background. Try one of: ```
Condense · step 4
**Purpose**: Segment the ceiling light and door, then extract 3D centroids for all three objects. **Reasoning**: [errored — condensed] **Next Goal**: [errored — condensed] **Code**: ```python # 1. Segment the ceiling light using text (fallback from box) seg_light = tools.SAM3.segment_image_by_text(InputImages[284], "long white ceiling light tube") # <-- ERROR # RuntimeError: SAM3.segment_image_by_text(prompt='long white ceiling light tube') produced no usable mask on this image (frame_index=284, confidence_threshold=0.3). SAM3 either detected nothing matching the prompt, or its mask logits collapsed to all background. Try one of: ```
Step 5
LLM
Purpose
Segment the door and the ceiling light, and then compute the 3D centroids for the monitor, light, and door.
Reasoning
I previously failed to segment the ceiling light. I will try a different prompt ("fluorescent light") and also segment the door. Once I have masks for all three, I will use the reconstruction to find their 3D centroids. I'll use the median of centroids if multiple masks are found, or just the centroid of the best mask.
Next Goal
Calculate the observer's forward and right vectors to determine if the door is to the left or right of the monitor.
Execute
Code
# 1. Segment the door in frame 950
seg_door = tools.SAM3.segment_image_by_text(InputImages[950], "door")

# 2. Try to segment the ceiling light in frame 284 again with a different prompt
# I'll try a few prompts to be sure
light_prompts = ["fluorescent light", "ceiling lamp", "white tube light"]
seg_light = None
for prompt in light_prompts:
    temp_seg = tools.SAM3.segment_image_by_text(InputImages[284], prompt)
    if temp_seg.num_objects > 0:
        seg_light = temp_seg
        print(f"Successfully segmented light with prompt: {prompt}")
        break

# 3. Extract 3D centroids
def get_obj_centroid(seg, recon, frame_idx):
    if seg is None or seg.num_objects == 0:
        return None
    # Use the first object found
    return seg.get_centroid_3d(recon, frame=frame_idx, object=0)

# Monitor centroid (from seg_monitor in Step 3)
p_monitor = get_obj_centroid(seg_monitor, recon, 0)

# Light centroid
p_light = get_obj_centroid(seg_light, recon, 284)

# Door centroid
p_door = get_obj_centroid(seg_door, recon, 950)

print(f"P_monitor: {p_monitor}")
print(f"P_light: {p_light}")
print(f"P_door: {p_door}")

# Visual verification of masks
if seg_door:
    fi_door = seg_door.frame_indices[0]
    show([InputImages[fi_door], seg_door.visualize(fi_door)])
if seg_light:
    fi_light = seg_light.frame_indices[0]
    show([InputImages[fi_light], seg_light.visualize(fi_light)])
Output
Successfully segmented light with prompt: fluorescent light
P_monitor: [-1.2835853  1.6072092 -0.8871776]
P_light: [ 0.478106   3.0092416 -0.5048477]
P_door: [-1.4424605   0.685904    0.64404464]
 [image: show_0001] 
 [image: show_0002] 
show_0001
show_0002
Step 6
LLM
Purpose
Calculate the observer's relative direction to the door and visually cross-validate with a BEV plot.
Reasoning
I have the 3D centroids for the ceiling light, monitor, and door. I will now implement the vector math to determine if the door is to the left or right of the monitor from the light's position. I'll also render a BEV to provide a second independent line of evidence.
Next Goal
Provide the final answer based on the quantitative result and visual verification.
Execute
Code
import numpy as np

# 1. Define the observer's coordinate system
p_light = p_light.astype(float)
p_monitor = p_monitor.astype(float)
p_door = p_door.astype(float)

# Forward vector: Light -> Monitor
f_vec = p_monitor - p_light
f_vec /= np.linalg.norm(f_vec)

# World up vector
u_vec = np.array([0, 1, 0])

# Right vector: f x u
r_vec = np.cross(f_vec, u_vec)
r_vec /= np.linalg.norm(r_vec)

# Vector from observer to door
v_door = p_door - p_light

# Dot product to find if door is left or right
score = np.dot(v_door, r_vec)

print(f"Forward vector: {f_vec}")
print(f"Right vector: {r_vec}")
print(f"Vector to door: {v_door}")
print(f"Score (dot product): {score}")

if score > 0:
    result = "right"
else:
    result = "left"

print(f"Quantitative result: The door is to the {result} of the monitor.")

# 2. Visual Cross-Validation with BEV
# Create a combined PerFrameMask for the BEV
# We can just use a list of masks or a custom object. 
# For render_bev, we can pass masks as a raw array (N, N_obj, H, W)
# Since we only have single-frame masks, we can create a dummy PerFrameMask or just use labels.

# To use render_bev effectively, we need a PerFrameMask object.
# Let's create a simple one by combining the masks we have.
class SimpleMasks:
    def __init__(self, masks, labels, frame_indices):
        self.masks = masks # (N, N_obj, H, W)
        self.labels = labels
        self.frame_indices = frame_indices
        self.num_objects = len(labels)
        self.num_frames = len(frame_indices)

# We'll use the frames we segmented
fi_mon = seg_monitor.frame_indices[0]
fi_light = seg_light.frame_indices[0]
fi_door = seg_door.frame_indices[0]

# For BEV, we need masks on the SAME frame or across frames.
# Since the objects are static, we can just use the masks from their respective frames.
# But render_bev expects masks aligned with the reconstruction frames.
# A simpler way: just use the centroids we already have to draw a plot.
plt.figure(figsize=(8, 8))
plt.scatter(p_light[0], p_light[2], c='yellow', label='Ceiling Light', s=100, marker='*')
plt.scatter(p_monitor[0], p_monitor[2], c='blue', label='Monitor', s=100)
plt.scatter(p_door[0], p_door[2], c='red', label='Door', s=100)
plt.quiver(p_light[0], p_light[2], f_vec[0], f_vec[2], color='green', scale=5, label='Forward')
plt.quiver(p_light[0], p_light[2], r_vec[0], r_vec[2], color='orange', scale=5, label='Right')
plt.xlabel('World X')
plt.ylabel('World Z')
plt.title('Top-down View (X-Z Plane)')
plt.legend()
plt.grid(True)
plt.axis('equal')
plt.show()
Output
Forward vector: [-0.7714093  -0.61392186 -0.16741459]
Right vector: [ 0.21208719  0.         -0.97725075]
Vector to door: [-1.92056653 -2.32333755  1.14889234]
Score (dot product): -1.5300834635363088
Quantitative result: The door is to the left of the monitor.
 [image: Top-down View (X-Z Plane)] 
Top-down View (X-Z Plane)
Step 7
LLM
Purpose
Finalize the answer based on the quantitative results and visual cross-validation.
Reasoning
1. **Quantitative Evidence**: * The observer's position was defined as the centroid of the ceiling light ($P_{light}$). * The forward vector ($\vec{f}$) was calculated as the unit vector from the ceiling light to the monitor ($P_{monitor}$). * The right vector ($\vec{r}$) was calculated as the cross product of the forward vector and the world-up vector ([0, 1, 0]). * The vector from the observer to the door ($\vec{v}_{door}$) was projected onto the right vector using a dot product. * The resulting score was approximately $-1.53$. A negative dot product indicates that the target (the door) is in the opposite direction of the right vector, meaning it is to the **left**. 2. **Visual Evidence**: * The top-down plot (X-Z plane) shows the observer (yellow star) facing the monitor (blue dot). * The green arrow indicates the forward direction. * The red dot (door) is clearly located to the left of the green arrow from the observer's perspective. Both independent lines of evidence (vector geometry and visual layout) consistently show that the door is to the left of the monitor.
Next Goal
Submit the final answer.
Execute
Code
ReturnAnswer("B")
Output
[ReturnAnswer] Answer submitted: B
Answer
B
Evaluation
Ground truth: B · Agent: B