ComfyUI/comfy_extras/nodes_custom_sampler.py

import comfy.samplers
import comfy.sample
from comfy.k_diffusion import sampling as k_diffusion_sampling
import latent_preview
import torch

class KarrasScheduler:
    @classmethod
    def INPUT_TYPES(s):
        return {"required":
                    {"steps": ("INT", {"default": 20, "min": 1, "max": 10000}),
                     "sigma_max": ("FLOAT", {"default": 14.614642, "min": 0.0, "max": 1000.0, "step":0.01, "round": False}),
                     "sigma_min": ("FLOAT", {"default": 0.0291675, "min": 0.0, "max": 1000.0, "step":0.01, "round": False}),
                     "rho": ("FLOAT", {"default": 7.0, "min": 0.0, "max": 100.0, "step":0.01, "round": False}),
                    }
               }
    RETURN_TYPES = ("SIGMAS",)
    CATEGORY = "_for_testing/custom_sampling"

    FUNCTION = "get_sigmas"

    def get_sigmas(self, steps, sigma_max, sigma_min, rho):
        sigmas = k_diffusion_sampling.get_sigmas_karras(n=steps, sigma_min=sigma_min, sigma_max=sigma_max, rho=rho)
        return (sigmas, )


class KSamplerSelect:
    @classmethod
    def INPUT_TYPES(s):
        return {"required":
                    {"sampler_name": (comfy.samplers.SAMPLER_NAMES, ),
                      }
               }
    RETURN_TYPES = ("SAMPLER",)
    CATEGORY = "_for_testing/custom_sampling"

    FUNCTION = "get_sampler"

    def get_sampler(self, sampler_name):
        sampler = comfy.samplers.sampler_class(sampler_name)()
        return (sampler, )

class SamplerCustom:
    @classmethod
    def INPUT_TYPES(s):
        return {"required":
                    {"model": ("MODEL",),
                    "add_noise": ("BOOLEAN", {"default": True}),
                    "noise_seed": ("INT", {"default": 0, "min": 0, "max": 0xffffffffffffffff}),
                    "cfg": ("FLOAT", {"default": 8.0, "min": 0.0, "max": 100.0, "step":0.5, "round": 0.01}),
                    "positive": ("CONDITIONING", ),
                    "negative": ("CONDITIONING", ),
                    "sampler": ("SAMPLER", ),
                    "sigmas": ("SIGMAS", ),
                    "latent_image": ("LATENT", ),
                     }
                }

    RETURN_TYPES = ("LATENT","LATENT")
    RETURN_NAMES = ("output", "denoised_output")

    FUNCTION = "sample"

    CATEGORY = "_for_testing/custom_sampling"

    def sample(self, model, add_noise, noise_seed, cfg, positive, negative, sampler, sigmas, latent_image):
        latent = latent_image
        latent_image = latent["samples"]
        if not add_noise:
            noise = torch.zeros(latent_image.size(), dtype=latent_image.dtype, layout=latent_image.layout, device="cpu")
        else:
            batch_inds = latent["batch_index"] if "batch_index" in latent else None
            noise = comfy.sample.prepare_noise(latent_image, noise_seed, batch_inds)

        noise_mask = None
        if "noise_mask" in latent:
            noise_mask = latent["noise_mask"]

        x0_output = {}
        callback = latent_preview.prepare_callback(model, sigmas.shape[-1] - 1, x0_output)

        disable_pbar = False
        samples = comfy.sample.sample_custom(model, noise, cfg, sampler, sigmas, positive, negative, latent_image, noise_mask=noise_mask, callback=callback, disable_pbar=disable_pbar, seed=noise_seed)

        out = latent.copy()
        out["samples"] = samples
        if "x0" in x0_output:
            out_denoised = latent.copy()
            out_denoised["samples"] = model.model.process_latent_out(x0_output["x0"].cpu())
        else:
            out_denoised = out
        return (out, out_denoised)

NODE_CLASS_MAPPINGS = {
    "SamplerCustom": SamplerCustom,
    "KarrasScheduler": KarrasScheduler,
    "KSamplerSelect": KSamplerSelect,
}