LTX 2.3 understands physics poorly, and no amount of prompt polish fixes that. This LoRA targets exactly that gap: it improves complex instruction understanding, logical action execution and frame stability. In the domino test the base model topples the wrong end; in the weight-on-box test the base model cracks the pedestal before the weight even lands.
Evidence note: three workflow JSON files ship with this episode and were parsed directly; node counts, checkpoint, LoRA strengths, samplers, sigma schedules and latent sizes below come from those files.
When this is useful
- Prompts describing a sequence of actions that the base model ignores or reorders.
- Object interactions where contact and physics have to look plausible.
- Hands and grip: the author's mirror and helmet tests both improve with the LoRA.
- Inserting the LoRA into first/last-frame and digital-human graphs, not only plain image-to-video.
How this differs from the previous build
This is the third VBVR iteration the author has covered, and the first from this particular studio.
- It is an I2V LoRA by the trainer's own description, so most demos are image-to-video.
- It also slots into first/last-frame and digital-human graphs, because LTX 2.3 digital human still starts from an image.
- The published graphs hide redundancy in node groups. Everything you would normally adjust is left outside the groups, and professional users can ungroup to reach the rest. Nothing is password-protected or hidden.
- Prompt rules come with the LoRA. Concrete, ordered, stepwise descriptions; vague mood words actively hurt.
Running it
- Load the LoRA with a standard Load LoRA node on top of the distilled checkpoint.
- Write the prompt in three parts: start state, action sequence, end state. Keep each step concrete and in order.
- Drop abstract adjectives — the author specifically calls out vague dynamic or dreamy phrasing as counterproductive.
- Run image-to-video first to feel the difference, holding the seed fixed against a no-LoRA run.
- For first/last-frame or digital-human work, drop the same LoRA into those graphs.
- If you need finer control, right-click the node groups and ungroup them.
Parameters, and where the numbers come from
| Item | Value in the shipped graphs |
|---|---|
| Checkpoint | ltx-2.3-22b-distilled.safetensors |
| Text encoder | gemma_3_12B_it.safetensors |
| Samplers | euler_ancestral_cfg_pp, euler_cfg_pp |
| CFG | 1 (CFGGuider) |
| Sigma schedule, main | 1.0, 0.99375, 0.9875, 0.98125, 0.975, 0.909375, 0.725, 0.421875, 0.0 |
| Sigma schedule, refine | 0.85, 0.7250, 0.4219, 0.0 |
| Video latent | 320x288, length 97 |
| Audio latent | 25 fps, 97 frames |
| Resize for references | 960x544 |
| NAG | scale 11, alpha 0.25, tau 2.5 |
| Image conditioning | strength 0.7 and 1 |
| LoRA, VBVR | Ltx2.3-Licon-VBVR-I2V-96000-R32.safetensors at 1.0 |
| LoRA, accelerate | ltx-2.3-22b-distilled-lora-384.safetensors at 0.5 |
Note the checkpoint here is the plain distilled build, not 1.1 — this episode predates the 1.1 release covered in episode 223.
Honest limits
- The LoRA improves compliance, not physical realism in absolute terms; the author says LTX 2.3's physics adherence is poor to begin with.
- Mirror reflections remain wrong even when the hands improve — the author concedes this while still calling the result better.
- Every comparison is a side-by-side visual with the seed held; nothing is scored.
- The studio behind the LoRA is still training, so this is an interim checkpoint.
- This episode uses the 96000 build; later episodes ship 240K and 390K versions that are not interchangeable.
Episode resources
RunningHub workflows
- VBVR image-to-video — https://www.runninghub.ai/post/2043983814732550145/?inviteCode=rh-v1111
- VBVR digital human — https://www.runninghub.ai/post/2043983796604768258/?inviteCode=rh-v1111
- LTX 2.3 + VBVR multi-image first/last frame — https://www.runninghub.ai/post/2043983802795560961/?inviteCode=rh-v1111
- Video tutorial (YouTube): https://www.youtube.com/watch?v=joHrYWYSpf8
- Chinese original (Bilibili): https://www.bilibili.com/video/BV1PQQuBcEd5
