VRGDG LTX Sigma Guide Release

The most frustrating LTX failure mode - at every version from 0.9 through 2.3 - is the video that never moves: the model locks onto the input frame and gives you a slow pan or a still. The cause is usually the image guide holding on too long. VRGDG LTX Sigma Guide Release exists to fix exactly that: it ramps an LTX image/video guide's influence down over your ManualSigmas, so the clip is allowed to leave its starting frame.

How it works

An LTX guide (the thing that pins your first frame in I2V) works through two mechanisms: a latent denoise lock that holds the latent close to the encoded guide, and per-guide attention that keeps the model looking back at the guide image. This node scales both of those over the sigma schedule - and it's honest about which knobs do what, with affect_latent_lock and affect_attention toggles so you can release one mechanism, the other, or both.

The influence_start/influence_end values define the range, and the semantics are simple: 1 preserves the guide's original strength, 0 releases it. The default is a ramp from 1 down to 0 - full grip on the first frame, none by the end - which is the classic "establish the shot, then let it drift free" setup. Set both ends to 1 and you've effectively bypassed the release; set both to 0 and the guide is dead weight from step one. The value can go up to 2, so you can also strengthen a guide over time if you want the video to pin harder toward the end.

The schedule is held flat outside the window you set: influence_start stays constant before start_percent, influence_end stays constant after end_percent. Same convention as the rest of this node family - only the percentage range you define is active.

The inputs that matter

• model - the model with the guide already attached; this node passes it through.
• sigmas - the same ManualSigmas your sampler uses. Timing mismatch here means the release happens at the wrong denoise stage.
• influence_start / influence_end - 1 preserves the guide, 0 releases it.
• start_percent / end_percent - where the ramp lives in the schedule.
• affect_latent_lock / affect_attention - both on by default; turn one off to debug which mechanism is causing a problem.

The output is a model that continues into your sampler, replacing the version you put in. Note this is a model-to-model pass, not a guider - it doesn't go in the guider slot.

Install

This is one node in the VRGameDevGirl pack: ComfyUI Manager → search vrgamedev (or add https://github.com/vrgamegirl19/comfyui-vrgamedevgirl), restart, hard-refresh. Manual: cd ComfyUI/custom_nodes && git clone https://github.com/vrgamegirl19/comfyui-vrgamedevgirl, then pip install -r requirements.txt. Windows portable: install Cython and scikit-build-core first; the pack's compiled deps are happier on Python 3.12.

Troubleshooting

If your I2V clips are still frozen with this node in the graph, first check the toggles - if affect_latent_lock is off, the pin may be holding regardless of your influence ramp. Then verify the sigmas match your sampler exactly, because a release timed to a schedule the sampler isn't using does nothing. And if you want a light touch, remember this node is a scaler, not a switch: a ramp from 1 to 0.3 still releases most of the grip while keeping a trace of the original frame for continuity.