Feat/Fix: clyb_geomextrap sampler (3 NFE) & Apple MPS dtype fix

This commit is contained in:
Clybius
2026-07-19 09:04:19 -05:00
parent 3d947721f6
commit 2f855bbeea
3 changed files with 319 additions and 8 deletions
+2
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@@ -12,6 +12,7 @@ NODE_CLASS_MAPPINGS = {
# Samplers
"SamplerClyb_BDF": clyb_Samplers.SamplerClyb_BDF,
"SamplerTaylorFlow": clyb_Samplers.SamplerTaylorFlow,
"SamplerClyb_GeomExtrap": clyb_Samplers.SamplerClyb_GeomExtrap,
"SamplerWrapperCFGPP": clyb_Samplers.SamplerWrapperCFGPP,
# Schedulers
"InverseSquaredScheduler": clyb_Schedulers.InverseSquaredScheduler,
@@ -27,6 +28,7 @@ NODE_DISPLAY_NAME_MAPPINGS = {
# Samplers
"SamplerClyb_BDF": "SamplerClyb_BDF",
"SamplerTaylorFlow": "SamplerTaylorFlow",
"SamplerClyb_GeomExtrap": "SamplerClyb_GeomExtrap",
"SamplerWrapperCFGPP": "SamplerWrapperCFGPP",
# Schedulers
"InverseSquaredScheduler": "InverseSquaredScheduler",
+10 -5
View File
@@ -203,9 +203,14 @@ class ClybGuidance:
# 1. Move to Frequency domain using 2D Fast Fourier Transform
# We use norm='ortho' to ensure the transform is unitary and preserves energy.
fft_cond = torch.fft.fftshift(torch.fft.fftn(cond.to(torch.float64), norm='ortho'))
fft_uncond = torch.fft.fftshift(torch.fft.fftn(uncond.to(torch.float64), norm='ortho'))
fft_out = torch.fft.fftshift(torch.fft.fftn(out.to(torch.float64), norm='ortho'))
device = cond.device
is_mps = device.type == "mps" if isinstance(device, torch.device) else "mps" in str(device)
precision_dtype = torch.float32 if is_mps else torch.float64
complex_dtype = torch.cfloat if is_mps else torch.cdouble
fft_cond = torch.fft.fftshift(torch.fft.fftn(cond.to(precision_dtype), norm='ortho'))
fft_uncond = torch.fft.fftshift(torch.fft.fftn(uncond.to(precision_dtype), norm='ortho'))
fft_out = torch.fft.fftshift(torch.fft.fftn(out.to(precision_dtype), norm='ortho'))
# 1. Create the 2D Hann window kernel for convolution
hann_1d = torch.signal.windows.hann(5, device=cond.device)
@@ -226,7 +231,7 @@ class ClybGuidance:
fft_cond_real = fft_cond_flat.real
fft_uncond_real = fft_uncond_flat.real
#guidance_direction = (cond - uncond)
local_avg_magnitude = F.conv1d(fft_cond_real, kernel.to(torch.float64), padding='same')
local_avg_magnitude = F.conv1d(fft_cond_real, kernel.to(precision_dtype), padding='same')
# 3. Normalize the magnitude map for each image in the batch to the [0, 1] range
# This makes the `strength` parameter behave consistently across different images.
@@ -250,7 +255,7 @@ class ClybGuidance:
print(local_scale)
guided_tensor = fft_cond + (local_scale.to(torch.cdouble) * (fft_cond_flat - fft_uncond_flat)).view(fft_cond.shape)
guided_tensor = fft_cond + (local_scale.to(complex_dtype) * (fft_cond_flat - fft_uncond_flat)).view(fft_cond.shape)
guided_tensor = torch.fft.ifftshift(guided_tensor)
guided_tensor = torch.fft.ifftn(guided_tensor, norm='ortho').real
+307 -3
View File
@@ -333,8 +333,9 @@ def sampler_taylor_flow(
denoised_cur = model(x, sigma_cur * s_in, **extra_args)
# 2. Build Vandermonde matrix from historical timesteps
precision_dtype = torch.float32 if (device.type == "mps" if isinstance(device, torch.device) else "mps" in str(device)) else torch.float64
R_p = _construct_vandermonde_flow(
history, sigma_cur, order, device, torch.float64
history, sigma_cur, order, device, precision_dtype
)
# 3. Solve for B coefficients
@@ -491,6 +492,308 @@ def sample_cfgpp(model, x, sigmas, extra_args=None, callback=None, disable=None,
)
# =============================================================================
# GEOM_EXTRAP SAMPLER - 3-NFE per step sampler that uses two geometric
# midpoints between sigma_cur and sigma_down to approximate a higher-order
# denoised prediction, then integrates that prediction into the noisy x
# latent. Uses the same selectable sigma_calc branches as SamplerTaylorFlow.
# =============================================================================
def _compute_ancestral_sigmas(sigma_cur, sigma_next, eta, sigma_calc, history, order):
"""
Compute (sigma_down, sigma_up) for the requested sigma_calc method.
Replicates the four branches from sampler_taylor_flow (clyb_Samplers.py:268-314)
verbatim so behaviour matches that sampler.
"""
h_n = sigma_next - sigma_cur
if sigma_calc == "clyb":
sigma_down = (
sigma_next ** 2 / (1.0 + math.log(1.0 + abs(sigma_next - sigma_cur)) * eta)
) ** 0.5
sigma_up = (sigma_next ** 2 - sigma_down ** 2) ** 0.5
elif sigma_calc == "taylor-expansion":
step_ratio = abs(h_n) / max(sigma_next, 1e-8)
taylor_factor = math.exp(-eta * step_ratio)
quadratic_correction = 1.0 - eta * 0.5 * step_ratio ** 2
sigma_down = sigma_next * taylor_factor * quadratic_correction
sigma_up = sigma_next * max(0.0, 1.0 - taylor_factor ** 2) ** 0.5
elif sigma_calc == "ancestral":
sigma_down, sigma_up = get_ancestral_step(sigma_cur, sigma_next, eta)
elif sigma_calc == "adaptive":
window_size = min(order, len(history))
if window_size >= 2:
history_list = list(history)
recent = history_list[-window_size:]
denoised_list = [d.float() for _, d in recent]
stacked = torch.stack(denoised_list)
mean_d = stacked.mean(dim=0)
var_val = ((stacked - mean_d) ** 2).mean().item()
norm_val = mean_d.pow(2).mean().item()
eps = 1e-8
if math.isfinite(var_val) and math.isfinite(norm_val):
normalized_metric = var_val / (var_val + abs(norm_val) + eps)
normalized_metric = min(1.0, max(0.0, normalized_metric))
else:
normalized_metric = 0.0
sigma_down = sigma_next * (1.0 - eta * normalized_metric)
sigma_down = max(0.0, min(sigma_next, sigma_down))
sigma_up = math.sqrt(max(0.0, sigma_next ** 2 - sigma_down ** 2))
else:
sigma_down = (
sigma_next ** 2
/ (1.0 + math.log(1.0 + abs(sigma_next - sigma_cur)) * eta)
) ** 0.5
sigma_up = (sigma_next ** 2 - sigma_down ** 2) ** 0.5
else:
sigma_down = (
sigma_next ** 2 / (1.0 + math.log(1.0 + abs(sigma_next - sigma_cur)) * eta)
) ** 0.5
sigma_up = (sigma_next ** 2 - sigma_down ** 2) ** 0.5
return sigma_down, sigma_up
@torch.no_grad()
def sampler_geom_extrap(
model,
x,
sigmas,
extra_args=None,
callback=None,
disable=None,
eta=1.0,
s_noise=1.0,
noise_sampler=None,
flow=False,
sigma_calc="clyb",
):
"""
Geometric-Midpoint Extrapolation sampler.
Per-step procedure (3 NFEs per step):
1. Sample at sigma_cur.
2. Integrate into x_mid1 at sigma_gm1 = sqrt(sigma_cur * sigma_down).
3. Sample at sigma_gm1.
4. Linearly extrapolate through (denoised1, denoised2) to predict at sigma_down.
5. Integrate denoised_pred into x_mid2 at sigma_gm2 = sqrt(sigma_gm1 * sigma_down).
6. Sample at sigma_gm2.
7. If not the final step, do a quadratic (3-point divided-difference) extrapolation
through (denoised1, denoised2, denoised3) to predict at sigma_down and integrate
that into x. If the final step, integrate denoised3 directly into x.
All intermediate sigmas (sigma_gm1, sigma_gm2) and lerp weight denominators are
clamped to >= 1e-4 for numerical stability near sigma = 0.
"""
extra_args = {} if extra_args is None else extra_args
seed = extra_args.get("seed", None)
noise_sampler = (
default_noise_sampler(x, seed=seed) if noise_sampler is None else noise_sampler
)
s_in = x.new_ones([x.shape[0]])
if len(sigmas) <= 1:
return x
# History buffer is needed for the "adaptive" sigma_calc branch.
history = collections.deque(maxlen=16)
# The last iteration index is len(sigmas) - 2 (since the loop goes 0..len(sigmas)-2,
# and sigmas[-1] is 0). On that step sigma_next == 0 and sigma_down == 0, so the
# 3-point extrapolation degenerates (denominators collapse). We skip extrapolation
# there and use denoised3 directly.
is_final_step = len(sigmas) - 2 if len(sigmas) >= 2 else 0
for i in trange(len(sigmas) - 1, disable=disable):
sigma_cur, sigma_next = sigmas[i], sigmas[i + 1]
h_n = sigma_next - sigma_cur
# ---- Ancestral sigma_down / sigma_up via the same branches as taylor_flow ----
sigma_down, sigma_up = _compute_ancestral_sigmas(
sigma_cur, sigma_next, eta, sigma_calc, history, order=16
)
# ---- Flow model coefficients (identical to sampler_taylor_flow lines 316-327) ----
alpha_ip1 = None
alpha_down = None
renoise_coeff = None
alpha_ratio = 1.0
if flow:
alpha_ip1 = 1.0 - sigma_next
alpha_down = 1.0 - sigma_down
renoise_coeff = (
sigma_next ** 2 - sigma_down ** 2 * alpha_ip1 ** 2 / alpha_down ** 2
) ** 0.5
alpha_ratio = alpha_ip1 / alpha_down if alpha_down != 0 else 1.0
# ---- Geometric midpoints, clamped for numerical stability ----
sigma_gm1 = (sigma_cur * sigma_down).clamp_min(1e-4).sqrt()
sigma_gm2 = (sigma_gm1 * sigma_down).clamp_min(1e-4).sqrt()
# ---- NFE 1: sample at sigma_cur ----
denoised1 = model(x, sigma_cur * s_in, **extra_args)
# ---- Integrate denoised1 into a noisy latent at sigma_gm1 ----
w_gm1 = (sigma_gm1 / sigma_cur).clamp_min(1e-4)
x_mid1 = denoised1.lerp(x, weight=w_gm1)
# ---- NFE 2: sample at sigma_gm1 ----
denoised2 = model(x_mid1, sigma_gm1 * s_in, **extra_args)
# ---- Linear extrapolation through (denoised1, denoised2) to predict at sigma_down ----
slope_12 = (denoised2 - denoised1) / (sigma_gm1 - sigma_cur)
denoised_pred = denoised2 + slope_12 * (sigma_down - sigma_gm1)
# ---- Integrate denoised_pred into a noisy latent at sigma_gm2 (from original x) ----
w_gm2 = (sigma_gm2 / sigma_gm1).clamp_min(1e-4)
x_mid2 = denoised_pred.lerp(x_mid1, weight=w_gm2)
# ---- NFE 3: sample at sigma_gm2 ----
denoised3 = model(x_mid2, sigma_gm2 * s_in, **extra_args)
# ---- Final vs non-final step ----
if i < is_final_step:
# Quadratic (3-point) extrapolation via Newton divided differences
d1 = (denoised2 - denoised1) / (sigma_gm1 - sigma_cur)
d2 = (denoised3 - denoised2) / (sigma_gm2 - sigma_gm1)
d2_div = (d2 - d1) / (sigma_gm2 - sigma_cur)
denoised_final = (
denoised3
+ d2 * (sigma_down - sigma_gm2)
+ d2_div * (sigma_down - sigma_gm2) * (sigma_down - sigma_gm1)
)
else:
# Final step: sigma_down = 0, just use denoised3 directly.
denoised_final = denoised3
# ---- Integrate the final denoised prediction into x at sigma_down ----
w_down = (sigma_down / sigma_gm2).clamp_min(1e-4)
x = denoised_final.lerp(x_mid2, weight=w_down)
# ---- Update history for "adaptive" sigma_calc branch on subsequent steps ----
history.append((sigma_cur, denoised_final))
# ---- Ancestral noise injection (identical to sampler_taylor_flow lines 369-374) ----
if sigma_next > 0 and eta > 0:
noise = noise_sampler(sigma_cur, sigma_next) * s_noise
if flow:
x = alpha_ratio * x + noise * renoise_coeff
else:
x = x + noise * sigma_up
# ---- Callback ----
if callback is not None:
callback(
{
"x": x,
"i": i,
"sigma": sigma_cur,
"sigma_hat": sigma_cur,
"denoised": denoised_final,
}
)
return x
@torch.no_grad()
def sample_geom_extrap(
model,
x,
sigmas,
extra_args=None,
callback=None,
disable=None,
eta=1.0,
s_noise=1.0,
noise_sampler=None,
sigma_calc="clyb",
):
"""Wrapper that detects flow vs non-flow then calls sampler_geom_extrap."""
flow = False
if isinstance(
model.inner_model.inner_model.model_sampling, comfy.model_sampling.CONST
):
flow = True
return sampler_geom_extrap(
model,
x,
sigmas,
extra_args=extra_args,
callback=callback,
disable=disable,
eta=eta,
s_noise=s_noise,
noise_sampler=noise_sampler,
flow=flow,
sigma_calc=sigma_calc,
)
class SamplerClyb_GeomExtrap:
"""
Geometric-Midpoint Extrapolation sampler.
3-NFE per step sampler that uses two geometric midpoints between sigma_cur and
sigma_down to build a 3-point quadratic extrapolation of the denoised prediction
at sigma_down, then integrates that prediction into the noisy x latent.
Compatible with both flow-matching (FLUX, SD3, Chroma) and non-flow models.
Parameters:
- eta: Ancestral sampling stochasticity (0=deterministic, 1=full stochastic)
- s_noise: Noise scaling factor
- sigma_calc: Ancestral sigma calculation method (clyb, taylor-expansion, ancestral, adaptive)
"""
@classmethod
def INPUT_TYPES(s):
return {
"required": {
"eta": (
"FLOAT",
{
"default": 1.0,
"min": 0.0,
"max": 100.0,
"step": 0.01,
"tooltip": "Ancestral sampling stochasticity (0=deterministic, 1=full stochastic)",
},
),
"s_noise": (
"FLOAT",
{
"default": 1.0,
"min": 0.0,
"max": 100.0,
"step": 0.01,
"tooltip": "Noise scaling factor",
},
),
"sigma_calc": (
["clyb", "taylor-expansion", "ancestral", "adaptive"],
{
"default": "clyb",
"tooltip": "Ancestral sigma calculation method: clyb (original log-based), taylor-expansion (exponential+quadratic), ancestral (standard k-diffusion), adaptive (history-based convergence-aware)",
},
),
}
}
RETURN_TYPES = ("SAMPLER",)
CATEGORY = "sampling/custom_sampling/samplers"
FUNCTION = "get_sampler"
def get_sampler(self, eta, s_noise, sigma_calc):
sampler = comfy.samplers.ksampler(
"geom_extrap",
{
"eta": eta,
"s_noise": s_noise,
"sigma_calc": sigma_calc,
},
)
return (sampler,)
# The following function adds the samplers during initialization, in __init__.py
def add_samplers():
from comfy.samplers import KSampler, k_diffusion_sampling
@@ -527,6 +830,7 @@ def add_samplers():
extra_samplers = {
"clyb_bdf": sample_clyb_bdf,
"taylor_flow": sample_taylor_flow,
"geom_extrap": sample_geom_extrap,
}
# Wrappers are NOT in the standard sampler dropdown. They are only reachable
@@ -604,7 +908,7 @@ class SamplerTaylorFlow:
{
"default": 1.0,
"min": 0.0,
"max": 1.0,
"max": 100.0,
"step": 0.01,
"tooltip": "Ancestral sampling stochasticity (0=deterministic, 1=full stochastic)",
},
@@ -614,7 +918,7 @@ class SamplerTaylorFlow:
{
"default": 1.0,
"min": 0.0,
"max": 2.0,
"max": 100.0,
"step": 0.01,
"tooltip": "Noise scaling factor",
},