Wrong Z_Image guidance scale implementation

[Trgtuan10]

Describe the bug

With cfg implementation of Z_image: pred = pos + current_guidance_scale * (pos - neg), the do_classifier_free_guidance function should be implement: return self._guidance_scale > 0, but currently in diffusers code: return self._guidance_scale > 1

For example, if I set guidance = 0.5, it works as guidance = 0 and it is incorrect.

Reproduction

No

Logs

System Info

0.36.0

Who can help?

@yiyixuxu @sayakpaul @DN6

[Trgtuan10]

Sorry if it shouldn't be in bug category

[sayakpaul]

Cc: @RuoyiDu @JerryWu-code from Z-Image team. They are the ones that contributed the pipeline.