sgl-project/sglang · error · ValueError

unsupported intrinsics shape {arr.shape}; expected (4,), (3,

Error message

unsupported intrinsics shape {arr.shape}; expected (4,), (3,3), or (F,3,3)

What it means

Raised by sana_wm_load_intrinsics when the loaded array is not shape (4,), (3,3), or (F,3,3) with F >= num_frames. The function converts fx, fy, cx, cy vectors or 3x3 matrices into a (num_frames, 4) array.

Source

Thrown at python/sglang/multimodal_gen/runtime/pipelines_core/stages/model_specific_stages/sana_wm/base.py:245

        raise ValueError(
            f"camera trajectory must have shape (F, 4, 4); got {c2w.shape}"
        )
    return c2w


def sana_wm_load_intrinsics(path: Path, num_frames: int) -> np.ndarray:
    arr = np.load(path).astype(np.float32)
    if arr.shape == (4,):
        return np.broadcast_to(arr, (num_frames, 4)).copy()
    if arr.shape == (3, 3):
        vec = np.array([arr[0, 0], arr[1, 1], arr[0, 2], arr[1, 2]], dtype=np.float32)
        return np.broadcast_to(vec, (num_frames, 4)).copy()
    if arr.ndim == 3 and arr.shape[1:] == (3, 3) and arr.shape[0] >= num_frames:
        arr = arr[:num_frames]
        return np.stack(
            [arr[:, 0, 0], arr[:, 1, 1], arr[:, 0, 2], arr[:, 1, 2]], axis=1
        )
    raise ValueError(
        f"unsupported intrinsics shape {arr.shape}; expected (4,), (3,3), or (F,3,3)"
    )


def snap_sana_wm_num_frames(
    num_frames: int, stride: int = 8, upper_bound: int | None = None
) -> int:
    if num_frames < 1:
        return 1
    if (num_frames - 1) % stride == 0:
        return min(num_frames, upper_bound) if upper_bound is not None else num_frames

    floor_candidate = num_frames - ((num_frames - 1) % stride)
    ceil_candidate = floor_candidate + stride
    snapped = (
        floor_candidate
        if num_frames - floor_candidate < ceil_candidate - num_frames
        else ceil_candidate

View on GitHub (pinned to 0132848349)

Solutions

1. Save intrinsics as a flat [fx, fy, cx, cy] array, or a single 3x3 K matrix
2. Ensure per-frame (F,3,3) files have at least num_frames entries
3. Double-check you're pointing at the intrinsics file, not the camera pose file

Example fix

# before
np.save(path, K4x4)  # (4,4)
# after
np.save(path, np.array([fx, fy, cx, cy]))  # (4,)

arr = np.load(path)
assert arr.shape in [(4,), (3,3)] or (arr.ndim == 3 and arr.shape[1:] == (3,3) and arr.shape[0] >= num_frames)

def intrinsics_ok(a, num_frames: int) -> bool:
    return a.shape in ((4,), (3, 3)) or (a.ndim == 3 and a.shape[1:] == (3, 3) and a.shape[0] >= num_frames)

When it happens

Trigger: Passing intrinsics arrays of shape (2,), (4,4), (F,4) with F<num_frames, or (F,3,3) with fewer frames than num_frames. Called from _prepare_intrinsics.

Common situations: Saving a 4x4 extrinsics matrix as intrinsics by mistake; a per-frame intrinsics file shorter than the requested frame count; saving (3,4) projection matrices.

Related errors

• camera trajectory must have shape (F, 4, 4); got {c2w.shape}
• action output dimensions must be non-zero, got {tuple(action
• action output must have shape [H, D] or [B, H, D], got {tupl
• SANA-WM denoising expects 5D latents shaped (B, C, T, H, W),
• condition_image tensor must be CHW or HWC with 1, 3, or 4 ch

AI-assisted analysis of sgl-project/sglang@0132848349 (2026-08-28). Data as JSON: /api/errors/e1902f2598be61fd. Report an issue: GitHub.