fix(ddim): validate eta is in [0, 1] in DDIMPipeline (#13367)
* fix(ddim): validate eta is in [0, 1] in DDIMPipeline.__call__
The DDIM paper defines η (eta) as a value that must lie in [0, 1]:
η=0 corresponds to deterministic DDIM, η=1 corresponds to DDPM.
The docstring already documented this constraint, but no runtime
validation was in place, so users could silently pass out-of-range
values (e.g. negative or >1) without any error.
Add an explicit ValueError check before the denoising loop so that
invalid eta values are caught early with a clear message.
Fixes #13362
Signed-off-by: NIK-TIGER-BILL <nik.tiger.bill@github.com>
* fix(ddim): downgrade eta out-of-range from error to warning
Per maintainer feedback from @yiyixuxu — the documentation is
sufficient; a hard ValueError is too strict. Replace with a
UserWarning so callers are informed without breaking existing code
that passes eta outside [0, 1].
Signed-off-by: NIK-TIGER-BILL <nik.tiger.bill@github.com>
* fix(ddim): use logger.warning instead of warnings.warn for eta validation
Address review request from @yiyixuxu: switch from warnings.warn() to
logger.warning() to be consistent with all other diffusers pipelines.
The eta validation check itself (0.0 <= eta <= 1.0) is unchanged.
Signed-off-by: NIK-TIGER-BILL <nik.tiger.bill@github.com>
---------
Signed-off-by: NIK-TIGER-BILL <nik.tiger.bill@github.com>
Co-authored-by: NIK-TIGER-BILL <nik.tiger.bill@github.com>
Co-authored-by: YiYi Xu <yixu310@gmail.com>
