Schedule Slice

The Schedule Slice node does exactly what its name says: it slices a verified schedule by terminal-inclusive sigma indices. Give it a schedule, a start_step, an end_step, and you get the sub-range back as a fresh, still-verifiable schedule. It's the pair of scissors in Sigmax's schedule-editing trio, alongside Concatenate and Resample.

Why cut a schedule at all? The honest answer is that most people won't need to - the Sigmax schedulers already have start_step/end_step slicing built in, so if you only want "steps 4 through 8 of this recipe," set it on the scheduler and be done. Schedule Slice earns its keep in the compound case: when you want to assemble a hybrid schedule from pieces of different recipes. Slice segment A from one schedule, slice segment B from another, and hand both to ScheduleConcatenate - which will join them at a shared boundary sigma. That's a real workflow for people building custom denoising trajectories across different recipe regimes, and Slice is the tool that makes the parts.

Inputs and outputs

• sigmas - the SIGMAS from a Sigmax scheduler.
• schedule_info - the accompanying JSON.
• start_step - where the slice starts (default 0).
• end_step - where it ends (default 1).

Outputs: the sliced sigmas and a schedule_info that records the slice. "Terminal-inclusive" means the end index includes the terminal/zero sigma - worth knowing when you're lining up two segments for a later concatenation, because the boundary sigma is exactly the kind of detail that has to match.

Installing

One pack, all nodes:

cd ComfyUI/custom_nodes
git clone https://github.com/rookiestar28/ComfyUI-Sigmax comfyui-sigmax

Restart, search Sigmax. ComfyUI Manager lists "ComfyUI-Sigmax". Python 3.10+, ComfyUI 0.29.0+, no extra dependencies.

Where people get burned

Reaching for Slice when the scheduler's own start_step/end_step would do the job - it's not wrong, just extra nodes. The real trap is slicing and then sampling the result without thinking about terminals: cut the zero-sigma end off and your sampler may not know where the clean image is. Keep the terminal in the slice unless you're deliberately building toward a concatenation. And as always with edited schedules: wire the result straight into the custom-sampling path and don't add a second scheduler on top.