LTX Director Motion Brush V2 Guide Attention

When you mix two kinds of guidance in an LTX 2.3 workflow - still Director keyframes and a motion-track IC-LoRA video - the IC-LoRA guide validation gets twitchy. It counts guide entries by type, and a mixed bag can fail token-count validation or, worse, quietly drop your motion conditioning. This node exists to stop that fight. It injects a synthetic guide-attention entry for the regular Director keyframes while preserving the motion IC-LoRA entry, so both survive into sampling and the validation stops complaining.

You'll find it in the included workflow between the sampler group's conditioning and the sampler itself. In plain terms: without it, running Director keyframes alongside the motion-track control is a coin flip between an error and a video that ignores one of your inputs. With it, both get a seat.

What you actually set

Three inputs, and you really only touch one:

• positive and negative - pass straight through from the sampler group's conditioning. Don't overthink these.
• director_attention_strength (default 0.35) - the one knob. It sets how strongly the regular still-image keyframes compete with the motion IC-LoRA guide.

The direction is easy to remember: higher values hold the source images harder (and risk a static result), lower values give motion more room (and risk the visible motion-track dots taking over). If your video is stiff or frozen, turn it down. If the output is drifting away from your storyboard or the dot trails are dominating, turn it up. 0.35 is a sensible starting point for full and distilled models both - the author's samples run there and look right.

Outputs

positive and negative conditioning, out the other side, ready to feed your KSampler. That's it. It doesn't touch latents or the model.

Install

Same pack, same deal:

comfy node install ltx-director-motion-brush
# or git clone into ComfyUI/custom_nodes, then restart ComfyUI

No extra dependencies beyond the pack's usual trio (ComfyUI-LTXVideo, comfyui-kjnodes, ComfyUI-Impact-Pack) and the Lightricks IC-LoRA models for LTX 2.3.

Why it matters more than it looks

This is a classic "one-line fix that makes the whole workflow work" node, and it's easy to underestimate. If you delete it from the example workflow, the mixed-guide setup either errors out or silently disables one branch of guidance - and silent is worse, because you'll spend an hour adjusting prompt weights that were never in play. It's also your primary lever when the balance feels off: instead of fighting per-segment guide strengths, one float on this node rescales the whole Director-vs-motion trade-off. Treat it as the master balance control for the Motion Brush workflow and you'll reach for it more than you expected.