VRGDG LTX Scheduled CFG Guider

ComfyUI's stock CFG Guider is dumb in a way that matters for LTX: it applies one scalar CFG to the entire denoise. Every step gets the same push. That's fine for stills, but LTX 2.3 is a model where people routinely want guidance early and almost none late - the distilled checkpoints literally run at CFG 1 by design. VRGDG LTX Scheduled CFG Guider is the drop-in replacement that fixes that: it selects one CFG value for each LTX sigma transition, straight from a schedule you build.

It's not a standalone node. It's the consumer half of a pair, and it's opinionated about its food - the cfg input only accepts a VRGDG_LTX_CFG_SCHEDULE, which is exactly what the sibling node VRGDG LTX CFG Schedule outputs. Think of them as one feature split across two boxes: the schedule node computes the values, this guider applies them inside sampling.

How it works

Where the normal CFG Guider takes a conditioning and a scalar and produces a GUIDER, this one takes model, positive, negative, and that precomputed cfg schedule, and produces a GUIDER that looks up the right CFG for wherever the sampler currently is in the sigma schedule. Because LTX sampling with ManualSigmas is a list of discrete transitions rather than a smooth ramp, the guider picks one value per transition instead of interpolating continuously - same model, same conditioning, different guidance at step three than at step forty.

The practical payoff: you can pin composition early with real CFG and let the second half of the denoise run essentially distilled, which is the setting the LTX community landed on for clean motion without cooked highlights. The CFG 1 baseline matters here too - at exactly 1.0 ComfyUI skips computing the unconditional pass, so a schedule that spends most of its length at 1 is also spending most of its time running at half cost.

The inputs that matter

• model, positive, negative - same three you'd feed any guider.
• cfg - the VRGDG_LTX_CFG_SCHEDULE from the schedule node. This is the whole point; there's no CFG number typed here.

The output is guider of type GUIDER, which plugs into the guider input of your KSampler-family node, replacing the stock CFG Guider entirely.

Install

It ships in the VRGameDevGirl pack, so install is pack-wide: ComfyUI Manager → Install Custom Nodes → search vrgamedev (or paste https://github.com/vrgamegirl19/comfyui-vrgamedevgirl), restart, hard-refresh the page. Manual: cd ComfyUI/custom_nodes && git clone https://github.com/vrgamegirl19/comfyui-vrgamedevgirl, then pip install -r requirements.txt with the pack's Python environment. On Windows portable, install Cython and scikit-build-core first or the voxcpm/llama-cpp build steps will bite you.

Troubleshooting

If the guider behaves like it's ignoring your schedule, the almost-certain cause is a mismatched sigma schedule: the CFG schedule was built from one ManualSigmas, the sampler runs on another, and the timings never line up. Feed both nodes the identical sigmas and the mystery goes away. Also remember the output is a GUIDER, not a model - wire it into the sampler's guider slot, not into the model input. And don't connect anything but the VRGDG schedule node into cfg; this is a deliberately narrow interface.