From 827bb1512b17e349238e69b2d4f463390a5b0d14 Mon Sep 17 00:00:00 2001
From: chaObserv <154517000+chaObserv@users.noreply.github.com>
Date: Wed, 17 Dec 2025 12:35:43 +0800
Subject: [PATCH] Add exp_heun_2_x0 sampler series (#11360)

---
 comfy/k_diffusion/sampling.py        | 11 +++++++++++
 comfy/samplers.py                    |  2 +-
 comfy_extras/nodes_custom_sampler.py | 11 ++++++++++-
 3 files changed, 22 insertions(+), 2 deletions(-)

diff --git a/comfy/k_diffusion/sampling.py b/comfy/k_diffusion/sampling.py
index 753c66afa..c004b3b47 100644
--- a/comfy/k_diffusion/sampling.py
+++ b/comfy/k_diffusion/sampling.py
@@ -1618,6 +1618,17 @@ def sample_seeds_2(model, x, sigmas, extra_args=None, callback=None, disable=Non
             x = x + sde_noise * sigmas[i + 1] * s_noise
     return x
 
+@torch.no_grad()
+def sample_exp_heun_2_x0(model, x, sigmas, extra_args=None, callback=None, disable=None, solver_type="phi_2"):
+    """Deterministic exponential Heun second order method in data prediction (x0) and logSNR time."""
+    return sample_seeds_2(model, x, sigmas, extra_args=extra_args, callback=callback, disable=disable, eta=0.0, s_noise=0.0, noise_sampler=None, r=1.0, solver_type=solver_type)
+
+
+@torch.no_grad()
+def sample_exp_heun_2_x0_sde(model, x, sigmas, extra_args=None, callback=None, disable=None, eta=1., s_noise=1., noise_sampler=None, solver_type="phi_2"):
+    """Stochastic exponential Heun second order method in data prediction (x0) and logSNR time."""
+    return sample_seeds_2(model, x, sigmas, extra_args=extra_args, callback=callback, disable=disable, eta=eta, s_noise=s_noise, noise_sampler=noise_sampler, r=1.0, solver_type=solver_type)
+
 
 @torch.no_grad()
 def sample_seeds_3(model, x, sigmas, extra_args=None, callback=None, disable=None, eta=1., s_noise=1., noise_sampler=None, r_1=1./3, r_2=2./3):
diff --git a/comfy/samplers.py b/comfy/samplers.py
index fa4640842..8340d376c 100755
--- a/comfy/samplers.py
+++ b/comfy/samplers.py
@@ -720,7 +720,7 @@ class Sampler:
         sigma = float(sigmas[0])
         return math.isclose(max_sigma, sigma, rel_tol=1e-05) or sigma > max_sigma
 
-KSAMPLER_NAMES = ["euler", "euler_cfg_pp", "euler_ancestral", "euler_ancestral_cfg_pp", "heun", "heunpp2","dpm_2", "dpm_2_ancestral",
+KSAMPLER_NAMES = ["euler", "euler_cfg_pp", "euler_ancestral", "euler_ancestral_cfg_pp", "heun", "heunpp2", "exp_heun_2_x0", "exp_heun_2_x0_sde", "dpm_2", "dpm_2_ancestral",
                   "lms", "dpm_fast", "dpm_adaptive", "dpmpp_2s_ancestral", "dpmpp_2s_ancestral_cfg_pp", "dpmpp_sde", "dpmpp_sde_gpu",
                   "dpmpp_2m", "dpmpp_2m_cfg_pp", "dpmpp_2m_sde", "dpmpp_2m_sde_gpu", "dpmpp_2m_sde_heun", "dpmpp_2m_sde_heun_gpu", "dpmpp_3m_sde", "dpmpp_3m_sde_gpu", "ddpm", "lcm",
                   "ipndm", "ipndm_v", "deis", "res_multistep", "res_multistep_cfg_pp", "res_multistep_ancestral", "res_multistep_ancestral_cfg_pp",
diff --git a/comfy_extras/nodes_custom_sampler.py b/comfy_extras/nodes_custom_sampler.py
index 71ea4e9ec..7ee4caac1 100644
--- a/comfy_extras/nodes_custom_sampler.py
+++ b/comfy_extras/nodes_custom_sampler.py
@@ -671,7 +671,16 @@ class SamplerSEEDS2(io.ComfyNode):
                 io.Float.Input("s_noise", default=1.0, min=0.0, max=100.0, step=0.01, round=False, tooltip="SDE noise multiplier"),
                 io.Float.Input("r", default=0.5, min=0.01, max=1.0, step=0.01, round=False, tooltip="Relative step size for the intermediate stage (c2 node)"),
             ],
-            outputs=[io.Sampler.Output()]
+            outputs=[io.Sampler.Output()],
+            description=(
+                "This sampler node can represent multiple samplers:\n\n"
+                "seeds_2\n"
+                "- default setting\n\n"
+                "exp_heun_2_x0\n"
+                "- solver_type=phi_2, r=1.0, eta=0.0\n\n"
+                "exp_heun_2_x0_sde\n"
+                "- solver_type=phi_2, r=1.0, eta=1.0, s_noise=1.0"
+            )
         )
 
     @classmethod