Create, reshape, inspect, combine, and reuse custom sigma schedules in ComfyUI. Model-family profiles provide practical starting curves without requiring a MODEL connection, while every resulting schedule remains editable.

Search for cozdx1 in the node menu to find all four nodes.

<img src="docs/images/dynamic-sigma-scheduler.png" width="900" alt="Dynamic Sigma Scheduler using the Illustrious SDXL and WAN profiles"> Illustrious/SDXL in the dark editor and WAN in the light editor.

What's new in v1.1.0

Profiles for Illustrious/SDXL, Anima, WAN, LTXV, Z-Image, Qwen-Image, Flux2, Krea2, and Custom.
Real-time previews for 11 schedulers, including beta57 and bong_tangent.
Editable graph endpoints, per-step values, curve shaping, and adjustable monotone smoothing.
Graph Sigmas output presets from 450×300 to 1200×800 with resolution-aware styling.
A compact SIGMAS to SCHEDULER_FUNC bridge for compatible Detailers and sampler nodes.
Korean localization, in-app documentation, and migration for workflows saved with v1.0.x.

Quick start

Add [cozdx1] Dynamic Sigma Scheduler.
Choose a model profile, scheduler, and step count.
Adjust the endpoints or shape, or edit the graph directly.
Connect sigmas to a compatible sampler, Graph Sigmas, Concat Sigmas, or Sigmas to Scheduler Func.

Profiles are starting points, not model auto-detection. Check the appropriate sigma range for the model, sampler, and workflow you are using.

Nodes

[cozdx1] Dynamic Sigma Scheduler

Builds a SIGMAS tensor and previews it immediately, before the queue runs. The output always contains steps + 1 values because both endpoints are included.

Model profiles

| Profile | Sampling family | Default shift | Default start | |---|---|---:|---:| | illustrious / sdxl | SDXL discrete | — | 15.0 | | anima | Discrete Flow | 3.0 | 1.0 | | wan | Discrete Flow | 8.0 | 1.0 | | ltxv | Flux | 2.37 | 1.0 | | z-image | Discrete Flow | 3.0 | 1.0 | | qwen-image | Flux | 1.15 | 1.0 | | flux2 | Flux | 2.02 | 1.0 | | krea2 | Flux | 1.15 | 1.0 | | custom | Manual | — | Keeps the current values |

Changing a profile selects its sampling family and default shift/endpoints. Select custom when you want to keep the current values and shape the schedule manually. Flow shift is disabled for Illustrious/SDXL and Custom.

Supported schedulers

simple, sgm_uniform, karras, exponential, ddim_uniform, beta, beta57, normal, linear_quadratic, kl_optimal, and bong_tangent.

Shape controls

sigma_start / sigma_end: Set the first and final values. Intermediate endpoints can be useful when schedules will be concatenated.
curve_factor: Positive values hold higher sigmas longer; negative values make them fall earlier.
smooth_strength: Blends manually edited sections from linear (0) to monotone cubic (1) without adding a rise between monotone control points.
show_steps: Shows all sigma values as editable six-decimal widgets. These widgets can also be converted to inputs.
black_theme: Changes only the editor theme.
Generate Curve: Discards manual edits and regenerates the curve from the current controls.
Reset Profile: Restores the selected profile's default shift and endpoints as well as its curve.

<img src="docs/images/curve-factor-comparison.png" width="900" alt="Comparison of negative and positive curve factor values"> Negative and positive <code>curve_factor</code> values move the curve in opposite directions. <img src="docs/images/smooth-strength-comparison.png" width="900" alt="Comparison of smooth strength zero and one"> <code>smooth_strength</code> blends a manual curve from linear interpolation to monotone cubic interpolation.

Manual editing

Click an empty graph position to add a control point, then drag it to reshape the curve. Shift-click a custom point to remove it. The first and last graph points stay synchronized with sigma_start and sigma_end.

| Direct graph editing | Editable per-step values | |:---:|:---:| | <img src="docs/images/manual-curve-editing.png" width="350" alt="Manual sigma curve editing"> | <a href="docs/images/editable-step-values.png"><img src="docs/images/editable-step-values.png" width="250" alt="Editable per-step sigma values"></a> | | Add and drag control points. | Enable show_steps to edit exact values. Click to view the full-size image. |

The emitted schedule is a one-dimensional float32 tensor.

[cozdx1] Graph Sigmas

Renders each connected sigma schedule as a ComfyUI IMAGE. Increase input_count to add matching SIGMAS inputs and IMAGE outputs.

black_theme: Selects a dark or light plot.
preview_resolution: Selects Compact (450×300), Default (600×400), Large (900×600), or High (1200×800).
Labels, strokes, markers, and spacing scale with the selected resolution. Existing workflows retain the 600×400 default.

[cozdx1] Concat Sigmas

Joins connected schedules in numeric input order. Increase input_count to add inputs.

The final value of each non-final schedule is removed so a shared boundary is not duplicated. For example, [1.0, 0.5] followed by [0.5, 0.0] becomes [1.0, 0.5, 0.0].

<img src="docs/images/concat-sigmas-example.png" width="1400" alt="Two sigma schedules concatenated into a single schedule"> Concat Sigmas joins multiple sigma sequences into one schedule.

Concat Sigmas does not alter values or force adjacent endpoints to match. Set the boundaries intentionally when a continuous schedule is required.

[cozdx1] Sigmas to Scheduler Func

Converts an existing SIGMAS schedule into a callable SCHEDULER_FUNC for compatible nodes.

Dynamic Sigma Scheduler → Sigmas to Scheduler Func → scheduler_func_opt

This includes Impact Pack's FaceDetailer, FaceDetailer (pipe), MaskDetailer (pipe), DetailerForEach variants, and other nodes that expose the same input type.

When the receiving node requests the same step count, the original schedule is returned unchanged.
When the step count differs, the curve is linearly resampled to steps + 1 values while preserving both endpoints.
The bridge applies no additional smoothing.
In Impact Pack, the connected scheduler_func_opt replaces the Detailer's scheduler during sampling. The visible scheduler widget remains in the interface, but its selected value is ignored.
Impact Pack is optional. Dynamic Sigmas does not import or modify it.

Installation

ComfyUI Manager

Open ComfyUI Manager.
Search for ComfyUI-Dynamic-Sigmas in Custom Nodes Manager.
Install it and restart ComfyUI.

Manual installation

Run the following from the ComfyUI custom_nodes directory:

git clone https://github.com/cozdx1/ComfyUI-Dynamic-Sigmas.git
cd ComfyUI-Dynamic-Sigmas
pip install -r requirements.txt

Restart ComfyUI after installation or update.

Updating

cd ComfyUI/custom_nodes/ComfyUI-Dynamic-Sigmas
git pull
pip install -r requirements.txt

See CHANGELOG.md for release details.

Compatibility notes

Workflows saved with v1.0.x load in custom mode while preserving their previous curve data and behavior.
Dynamic inputs and outputs are currently limited by ComfyUI's subgraph handling. Expand them on the main graph before converting a node to a subgraph.
Appropriate sigma values vary by model and sampler. Dynamic Sigmas does not validate whether a custom schedule is suitable for a particular sampling setup.
The Detailer bridge adapts the supplied curve to the step count requested by the receiving node. Verify the effective denoise range when replacing an established Detailer scheduler.

License

MIT License