Fix Wan2.2 low noise model load LoRA bug

diffsynth_engine/pipelines/wan_video.py

@@ -95,6 +95,11 @@ def convert(self, state_dict):
         return state_dict
 
 
+class WanLowNoiseLoRAConverter(WanLoRAConverter):
+    def convert(self, state_dict):
+        return {"dit2": super().convert(state_dict)["dit"]}
+
+
 class WanVideoPipeline(BasePipeline):
     lora_converter = WanLoRAConverter()
 
@@ -144,8 +149,24 @@ def load_loras(self, lora_list: List[Tuple[str, float]], fused: bool = True, sav
         )
         super().load_loras(lora_list, fused, save_original_weight)
 
+    def load_loras_low_noise(self, lora_list: List[Tuple[str, float]], fused: bool = True, save_original_weight: bool = False):
+        assert self.dit2 is not None, "low noise LoRA can only be loaded when low noise model (dit2) is initialized"
+        assert self.config.tp_degree is None or self.config.tp_degree == 1, (
+            "load LoRA is not allowed when tensor parallel is enabled; "
+            "set tp_degree=None or tp_degree=1 during pipeline initialization"
+        )
+        assert not (self.config.use_fsdp and fused), (
+            "load fused LoRA is not allowed when fully sharded data parallel is enabled; "
+            "either load LoRA with fused=False or set use_fsdp=False during pipeline initialization"
+        )
+        self.lora_converter = WanLowNoiseLoRAConverter()
+        super().load_loras(lora_list, fused, save_original_weight)
+        self.lora_converter = WanLoRAConverter()
+
     def unload_loras(self):
         self.dit.unload_loras()
+        if self.dit2 is not None:
+            self.dit2.unload_loras()
         self.text_encoder.unload_loras()
 
     def get_default_fps(self) -> int: