Comfy-Org/ComfyUI · error · ValueError

Unrecognized interpolation method '{method}'.

Error message

Unrecognized interpolation method '{method}'.

What it means

Raised by the hook keyframe interpolation helper when the interpolation method string does not match any of the four supported constants: linear, ease-in, ease-out, ease-in-out. The comparison is exact against class constants, so any other spelling (including case or separator differences) lands in the final else.

Source

Thrown at comfy/hooks.py:563

    _LIST = [LINEAR, EASE_IN, EASE_OUT, EASE_IN_OUT]

    @classmethod
    def get_weights(cls, num_from: float, num_to: float, length: int, method: str, reverse=False):
        diff = num_to - num_from
        if method == cls.LINEAR:
            weights = torch.linspace(num_from, num_to, length)
        elif method == cls.EASE_IN:
            index = torch.linspace(0, 1, length)
            weights = diff * np.power(index, 2) + num_from
        elif method == cls.EASE_OUT:
            index = torch.linspace(0, 1, length)
            weights = diff * (1 - np.power(1 - index, 2)) + num_from
        elif method == cls.EASE_IN_OUT:
            index = torch.linspace(0, 1, length)
            weights = diff * ((1 - np.cos(index * np.pi)) / 2) + num_from
        else:
            raise ValueError(f"Unrecognized interpolation method '{method}'.")
        if reverse:
            weights = weights.flip(dims=(0,))
        return weights

def get_sorted_list_via_attr(objects: list, attr: str) -> list:
    if not objects:
        return objects
    elif len(objects) <= 1:
        return [x for x in objects]
    # now that we know we have to sort, do it following these rules:
    # a) if objects have same value of attribute, maintain their relative order
    # b) perform sorting of the groups of objects with same attributes
    unique_attrs = {}
    for o in objects:
        val_attr = getattr(o, attr)
        attr_list: list = unique_attrs.get(val_attr, list())
        attr_list.append(o)
        if val_attr not in unique_attrs:

View on GitHub (pinned to 1c6d8d45b3)

Solutions

1. Use one of the exact supported values: 'linear', 'ease-in', 'ease-out', 'ease-in-out'
2. If building prompts programmatically, validate against that allowlist before submitting
3. Check for stray whitespace/case in the serialized workflow JSON

Example fix

# before
hooks.CreateHookKeyframesInterpolation(..., strength_interpolation='ease_in')
# after
hooks.CreateHookKeyframesInterpolation(..., strength_interpolation='ease-in')

VALID = {'linear', 'ease-in', 'ease-out', 'ease-in-out'}
method = method.strip().lower()
assert method in VALID, f'interpolation must be one of {sorted(VALID)}'

def is_valid_interpolation(method: str) -> bool:
    return method in {'linear', 'ease-in', 'ease-out', 'ease-in-out'}

When it happens

Trigger: Calling CreateHookKeyframesInterpolation (or ScheduleConditions) with strength_interpolation='sine', 'Ease In', 'ease_in', or any unsupported name. The check is `method == cls.LINEAR` etc., so exact string equality applies.

Common situations: Hand-typing the interpolation name in a combo or API prompt JSON; API callers forwarding arbitrary strings; locale/typo issues like 'easein' or trailing whitespace from generated workflow JSON.

Related errors

• Need at least {require_count} hooks to combine, but only had
• Keyframe times must be finite numbers in seconds; got '{valu
• Aleph2 supports at most 5 keyframes.
• floats_strength must be either an iterable input or a float,
• INVALID_TAG_FILTER

AI-assisted analysis of Comfy-Org/ComfyUI@1c6d8d45b3 (2026-08-14). Data as JSON: /api/errors/ea6a2c96f8ccdf6c. Report an issue: GitHub.