Add basic PAG node.

comfy/model_patcher.py

@@ -18,6 +18,26 @@ def apply_weight_decompose(dora_scale, weight):
 
     return weight * (dora_scale / weight_norm)
 
+def set_model_options_patch_replace(model_options, patch, name, block_name, number, transformer_index=None):
+    to = model_options["transformer_options"].copy()
+
+    if "patches_replace" not in to:
+        to["patches_replace"] = {}
+    else:
+        to["patches_replace"] = to["patches_replace"].copy()
+
+    if name not in to["patches_replace"]:
+        to["patches_replace"][name] = {}
+    else:
+        to["patches_replace"][name] = to["patches_replace"][name].copy()
+
+    if transformer_index is not None:
+        block = (block_name, number, transformer_index)
+    else:
+        block = (block_name, number)
+    to["patches_replace"][name][block] = patch
+    model_options["transformer_options"] = to
+    return model_options
 
 class ModelPatcher:
     def __init__(self, model, load_device, offload_device, size=0, current_device=None, weight_inplace_update=False):
@@ -109,16 +129,7 @@ class ModelPatcher:
         to["patches"][name] = to["patches"].get(name, []) + [patch]
 
     def set_model_patch_replace(self, patch, name, block_name, number, transformer_index=None):
-        to = self.model_options["transformer_options"]
-        if "patches_replace" not in to:
-            to["patches_replace"] = {}
-        if name not in to["patches_replace"]:
-            to["patches_replace"][name] = {}
-        if transformer_index is not None:
-            block = (block_name, number, transformer_index)
-        else:
-            block = (block_name, number)
-        to["patches_replace"][name][block] = patch
+        self.model_options = set_model_options_patch_replace(self.model_options, patch, name, block_name, number, transformer_index=transformer_index)
 
     def set_model_attn1_patch(self, patch):
         self.set_model_patch(patch, "attn1_patch")

comfy_extras/nodes_pag.py

@@ -0,0 +1,56 @@
+#Modified/simplified version of the node from: https://github.com/pamparamm/sd-perturbed-attention
+#If you want the one with more options see the above repo.
+
+#My modified one here is more basic but has less chances of breaking with ComfyUI updates.
+
+import comfy.model_patcher
+import comfy.samplers
+
+class PerturbedAttentionGuidance:
+    @classmethod
+    def INPUT_TYPES(s):
+        return {
+            "required": {
+                "model": ("MODEL",),
+                "scale": ("FLOAT", {"default": 3.0, "min": 0.0, "max": 100.0, "step": 0.1, "round": 0.01}),
+            }
+        }
+
+    RETURN_TYPES = ("MODEL",)
+    FUNCTION = "patch"
+
+    CATEGORY = "_for_testing"
+
+    def patch(self, model, scale):
+        unet_block = "middle"
+        unet_block_id = 0
+        m = model.clone()
+
+        def perturbed_attention(q, k, v, extra_options, mask=None):
+            return v
+
+        def post_cfg_function(args):
+            model = args["model"]
+            cond_pred = args["cond_denoised"]
+            cond = args["cond"]
+            cfg_result = args["denoised"]
+            sigma = args["sigma"]
+            model_options = args["model_options"].copy()
+            x = args["input"]
+
+            if scale == 0:
+                return cfg_result
+
+            # Replace Self-attention with PAG
+            model_options = comfy.model_patcher.set_model_options_patch_replace(model_options, perturbed_attention, "attn1", unet_block, unet_block_id)
+            (pag,) = comfy.samplers.calc_cond_batch(model, [cond], x, sigma, model_options)
+
+            return cfg_result + (cond_pred - pag) * scale
+
+        m.set_model_sampler_post_cfg_function(post_cfg_function, disable_cfg1_optimization=True)
+
+        return (m,)
+
+NODE_CLASS_MAPPINGS = {
+    "PerturbedAttentionGuidance": PerturbedAttentionGuidance,
+}

nodes.py

@@ -1942,6 +1942,7 @@ def init_custom_nodes():
         "nodes_differential_diffusion.py",
         "nodes_ip2p.py",
         "nodes_model_merging_model_specific.py",
+        "nodes_pag.py",
     ]
 
     import_failed = []