VRGDG LTX Sigma Advanced Guider

The stock LTX guider lineup makes you juggle three separate features - CFG, spatio-temporal guidance (STG), and variance rescale - across different nodes, and none of them schedule. VRGDG LTX Sigma Advanced Guider folds all three into a single ManualSigmas-driven guider where each one can ramp from a start value to an end value across your denoise. If you've been stacking three guiders to get "strong early, relaxed late," this is the one node that does it.

How it works

You feed it model, positive, negative, and the same sigmas your sampler uses. From there it manages three scheduled parameters in parallel:

• CFG (cfg_start → cfg_end) - classic classifier-free guidance, ramping across your window.
• STG (stg_start → stg_end) - spatio-temporal guidance, which perturbs specific LTX transformer blocks to keep video temporally coherent. STG arrived with the 0.9.6 era's STGGuiderAdvanced and is easy to overdo - the community's repeated warning is that over-applied STG gives hair and skin an exaggerated, unnatural look. The stg_blocks field (default "14, 19") is a comma-separated list of which transformer blocks get perturbed.
• Variance rescale (rescale_start → rescale_end) - the rescale that keeps the latent's statistics sane when guidance pushes it around.

The one behavior to internalize: APG replaces CFG, it doesn't stack on it. The guidance_mode enum lets you pick CFG or APG, and if you choose APG the guided vector is the APG output - you don't get both passes. The APG controls (apg_eta, apg_norm_threshold, apg_momentum, and the cfg_star toggle) tune that alternative guidance scheme. This is the setting people get burned by, because it looks like "add APG on top" and behaves like "swap your guidance engine."

Outside the start_percent/end_percent window everything resets to neutral: CFG drops to 1, STG and rescale drop to 0. Like the rest of this node family, the parts of the schedule you don't touch are deliberately boring.

The inputs that matter

• sigmas - same ManualSigmas as your sampler; mismatches silently desync all three schedules.
• cfg_start/cfg_end - default 4/4; drop the end value toward 1 for distilled-friendly late steps.
• stg_start/stg_end - default 1/1. Above ~1.5 STG starts to warp skin and hair.
• stg_blocks - which transformer blocks to perturb; "14, 19" is a sane starting set.
• guidance_mode - CFG or APG, and they're mutually exclusive.

The output is guider of type GUIDER, into your sampler's guider slot.

Install

Pack-wide install via ComfyUI Manager (search vrgamedev, or add https://github.com/vrgamegirl19/comfyui-vrgamedevgirl), restart, hard-refresh. Manual: git clone https://github.com/vrgamegirl19/comfyui-vrgamedevgirl into custom_nodes, then pip install -r requirements.txt. On Windows portable, install Cython and scikit-build-core first, and prefer Python 3.12 over 3.13 for the build-heavy deps.

Troubleshooting

The classic confusion is thinking APG is a bonus pass. If your output suddenly looks weakly guided after switching it on, that's APG replacing CFG, not failing - read the description again. If faces get waxy, your STG is too high or stg_blocks is over-perturbing. If nothing seems scheduled at all, check that the sigmas feeding this guider are literally the same object your sampler runs on.