🅛🅣🅧 LTXV Apply STG

STG - Spatio-Temporal Guidance - is one of the tricks that makes LTX video hold together instead of turning to soup, and this node is the low-level control for it. Where the STG preset nodes hand you a bundle of tuned settings, Apply STG does the plumbing underneath: it marks which transformer blocks the guidance perturbs. Its whole job, per the description, is to define the blocks to apply STG to.

How it works

STG improves structure and motion by running a deliberately weakened version of the model in parallel and steering away from that degraded prediction. The "weakening" happens by perturbing specific attention blocks - and which blocks you perturb changes the character and strength of the effect. This node patches the model so the guidance targets the block indices you give it, then passes the patched model on to the sampler and guider that actually do the STG steering. It's the difference between "STG is on" and "STG is on here."

For most people the block choice is set-and-forget; the defaults are chosen to work. But if you're chasing a specific artifact or tuning a custom workflow, this is where you reach.

The inputs and output

• model - the LTX model to patch.
• block_indices (default "14, 19") - a comma-separated list of the transformer blocks STG perturbs. The default targets a couple of mid-to-late blocks that give a good structure boost without wrecking the image.

The output is the patched model. Note it's lowercase model here - same MODEL type, wired onward exactly like any model patch.

Installing it

• ComfyUI Manager - search LTXVideo, install, restart.
• Manual - cd ComfyUI/custom_nodes && git clone https://github.com/Lightricks/ComfyUI-LTXVideo, then restart.

Common issues

Hair and skin look exaggerated, waxy, or over-sharpened. That's the classic STG-too-strong symptom - one user described it as "an exaggerated and unnatural appearance." Adding more blocks to block_indices increases the effect, so if you're seeing this, use fewer blocks, not more, or step back to the stock 14, 19.

No visible effect. STG only does something in combination with the STG guider that reads this patch. Applying it and then sampling with a plain guider means the block marking goes unused - make sure the guidance side is actually STG-aware.

You don't know which blocks to pick. Then don't overthink it - leave the default, or use the STG Advanced Presets node instead and let a tuned preset make the call. Hand-picking block indices is an expert knob, and the defaults exist because they work for most clips.