51 lines
1.8 KiB
Markdown
51 lines
1.8 KiB
Markdown
# FunPack Hybrid Euler 2S Sampler
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This node outputs a ComfyUI `SAMPLER` object that can be connected directly into `CustomSamplerAdvanced` / `SamplerCustomAdvanced`.
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## Purpose
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It is designed as a quality/speed compromise between:
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- `euler_ancestral`: fast, reliable, one model evaluation per step
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- full 2S-style samplers: higher quality, but more expensive because they need an extra evaluation every step
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This sampler keeps classic Euler ancestral for most of the schedule, then applies a DPM-Solver++(2S)-style correction only on the late denoise steps where fine detail and cleanup usually matter most.
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## Parameters
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**eta**: Ancestral stochasticity. `1.0` keeps normal ancestral behavior.
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**s_noise**: Noise multiplier for ancestral noise injection.
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**high_quality_pct**: Fraction of the *late* denoise steps that receive the extra 2S correction.
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Example: `0.35` means only the last 35% of steps pay the extra compute cost.
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**correction_blend**: Blend between pure Euler ancestral and the late-step 2S correction.
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- `0.0` = behaves like Euler ancestral
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- `1.0` = full late-step correction
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## Recommended starting values
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- `eta = 1.0`
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- `s_noise = 1.0`
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- `high_quality_pct = 0.30` to `0.40`
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- `correction_blend = 1.0`
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For a safer first test, try:
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- `high_quality_pct = 0.25`
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- `correction_blend = 0.7`
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## Expected behavior
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Compared to plain `euler_ancestral`, this sampler should usually:
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- preserve more late-stage detail
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- clean up texture and edge quality better
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- cost noticeably less than a full 2S sampler
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## Limitation
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This node improves the **sampler-side quality/speed tradeoff**. It does **not** reduce the underlying cost of CFG++ guidance itself. If the goal becomes specifically “CFG++ quality at lower guidance cost”, that likely requires a custom `GUIDER`, not just a custom `SAMPLER`.
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