VRGDG LTX CFG Schedule

LTX is the model where one CFG number is never quite right. The distilled checkpoints want CFG around 1, the dev model wants more, and the community's standard answer - "if the lights are overcooked, tune CFG between 1.1 and 2.0" - is really saying different parts of the denoise want different values. That's the whole point of VRGDG LTX CFG Schedule: it hands you a CFG value for every sigma transition in your schedule instead of one flat number.

It comes from VRGameDevGirl's music-video pack (the same pack that ships the AI Video Builder), where scheduled CFG is part of the LTX 2.3 toolkit. If you're rendering a scene and the early structure is solid but the finish is overcooked, this is the dial to reach for.

How it works

The node takes the same ManualSigmas that your sampler is using - that's the sigmas input, and it's the important one. Because a sigma schedule isn't a smooth ramp but a series of discrete transitions, the node creates exactly one CFG value per transition. Between cfg_scale_start and cfg_scale_end it interpolates across the schedule using your chosen interpolation (linear, ease_in, or ease_out). Outside the start_percent/end_percent window it just sets CFG to 1.0 - the distilled LTX baseline - so the parts of the schedule you didn't touch stay safe instead of guessing.

That "outside the range is 1.0" detail is the whole design. You pick the percentage window where you want guidance, and everywhere else the node assumes distilled behavior. Want heavy CFG early to lock composition and none late so motion stays free? Set cfg_scale_start to 5, cfg_scale_end to 1, and leave the percents alone. Want a brief boost in the middle? Move start_percent and end_percent to bracket just that span.

The output is a single socket, cfg, of type VRGDG_LTX_CFG_SCHEDULE. It is not a number you can read - it only makes sense wired into the VRGDG LTX Scheduled CFG Guider, which is the node that actually consumes it during sampling. The node description is explicit: connect this only to that guider. Don't try to route it into anything else.

The inputs that matter

• sigmas - the ManualSigmas feeding your sampler. Must be the same schedule the sampler uses, or your CFG timing won't match the actual denoise.
• cfg_scale_start / cfg_scale_end - the guidance range to interpolate across.
• start_percent / end_percent - the window where the schedule is active; everything outside gets 1.0.
• interpolation - how the CFG moves between the two ends; linear is the boring-but-predictable choice.

Install

Grab the whole pack through ComfyUI Manager: search vrgamedev (or add https://github.com/vrgamegirl19/comfyui-vrgamedevgirl directly), restart ComfyUI, and hard-refresh the browser page. Manual install is the standard cd ComfyUI/custom_nodes && git clone https://github.com/vrgamegirl19/comfyui-vrgamedevgirl followed by pip install -r requirements.txt. On Windows portable builds the README tells you to install Cython and scikit-build-core first - the pack's heavier deps like voxcpm and llama-cpp-python need to compile, and Python 3.12 is friendlier than 3.13 there.

Troubleshooting

The usual failure is a schedule that does nothing: if your guider is set up but CFG never seems to change, check that both the schedule node and the sampler are fed the same ManualSigmas, and that start_percent/end_percent actually cover the range you're testing. And remember this node is half of a pair - it generates the schedule, it doesn't apply it. The Scheduled CFG Guider is the other half, and it's the one that goes into your sampler.