Add nested style of dual cfg to DualCFGGuider node. (#8965)

Author: comfyanonymous

comfy_extras/nodes_custom_sampler.py

@@ -683,9 +683,10 @@ def get_guider(self, model, positive, negative, cfg):
         return (guider,)
 
 class Guider_DualCFG(comfy.samplers.CFGGuider):
-    def set_cfg(self, cfg1, cfg2):
+    def set_cfg(self, cfg1, cfg2, nested=False):
         self.cfg1 = cfg1
         self.cfg2 = cfg2
+        self.nested = nested
 
     def set_conds(self, positive, middle, negative):
         middle = node_helpers.conditioning_set_values(middle, {"prompt_type": "negative"})
@@ -695,14 +696,20 @@ def predict_noise(self, x, timestep, model_options={}, seed=None):
         negative_cond = self.conds.get("negative", None)
         middle_cond = self.conds.get("middle", None)
         positive_cond = self.conds.get("positive", None)
-        if model_options.get("disable_cfg1_optimization", False) == False:
-            if math.isclose(self.cfg2, 1.0):
-                negative_cond = None
-                if math.isclose(self.cfg1, 1.0):
-                    middle_cond = None
 
-        out = comfy.samplers.calc_cond_batch(self.inner_model, [negative_cond, middle_cond, positive_cond], x, timestep, model_options)
-        return comfy.samplers.cfg_function(self.inner_model, out[1], out[0], self.cfg2, x, timestep, model_options=model_options, cond=middle_cond, uncond=negative_cond) + (out[2] - out[1]) * self.cfg1
+        if self.nested:
+            out = comfy.samplers.calc_cond_batch(self.inner_model, [negative_cond, middle_cond, positive_cond], x, timestep, model_options)
+            pred_text = comfy.samplers.cfg_function(self.inner_model, out[2], out[1], self.cfg1, x, timestep, model_options=model_options, cond=positive_cond, uncond=middle_cond)
+            return out[0] + self.cfg2 * (pred_text - out[0])
+        else:
+            if model_options.get("disable_cfg1_optimization", False) == False:
+                if math.isclose(self.cfg2, 1.0):
+                    negative_cond = None
+                    if math.isclose(self.cfg1, 1.0):
+                        middle_cond = None
+
+            out = comfy.samplers.calc_cond_batch(self.inner_model, [negative_cond, middle_cond, positive_cond], x, timestep, model_options)
+            return comfy.samplers.cfg_function(self.inner_model, out[1], out[0], self.cfg2, x, timestep, model_options=model_options, cond=middle_cond, uncond=negative_cond) + (out[2] - out[1]) * self.cfg1
 
 class DualCFGGuider:
     @classmethod
@@ -714,6 +721,7 @@ def INPUT_TYPES(s):
                     "negative": ("CONDITIONING", ),
                     "cfg_conds": ("FLOAT", {"default": 8.0, "min": 0.0, "max": 100.0, "step":0.1, "round": 0.01}),
                     "cfg_cond2_negative": ("FLOAT", {"default": 8.0, "min": 0.0, "max": 100.0, "step":0.1, "round": 0.01}),
+                    "style": (["regular", "nested"],),
                      }
                 }
 
@@ -722,10 +730,10 @@ def INPUT_TYPES(s):
     FUNCTION = "get_guider"
     CATEGORY = "sampling/custom_sampling/guiders"
 
-    def get_guider(self, model, cond1, cond2, negative, cfg_conds, cfg_cond2_negative):
+    def get_guider(self, model, cond1, cond2, negative, cfg_conds, cfg_cond2_negative, style):
         guider = Guider_DualCFG(model)
         guider.set_conds(cond1, cond2, negative)
-        guider.set_cfg(cfg_conds, cfg_cond2_negative)
+        guider.set_cfg(cfg_conds, cfg_cond2_negative, nested=(style == "nested"))
         return (guider,)
 
 class DisableNoise: