AInVFX Fluid IC-LoRA: Paint Keyframes Into Smoke and Fire on LTX 2.5

Overview

The idea is simple: instead of setting up a fluid simulation or hunting for stock footage, you paint. Flat colour blobs on the keyframes, black frames everywhere else, and a prompt with the trigger word ainvfxfluid. Thanks to LTX 2.5's speed, a 121-frame clip renders in about 60 seconds on a laptop RTX 4090, which makes the loop from sketch to usable VFX plate genuinely interactive.

The LoRA was trained as the teaching example for AInVFX's IC-LoRA bootcamp, on 52 free-to-use clips from Pexels covering smoke, steam and fire only. Other fluid types may work but are hit or miss. The file is a rank-32, 654 MB LoRA in ComfyUI format, derived from LTX 2.5 and carrying the same LTX-2.x Community License.

Paint control, get footage

The control side is deliberately low-tech. Paint flat colour blobs where you want the fluid, optionally add intermediate keyframes, and the LoRA animates from one painted frame to the next while matching the blob shape and colour:

The model card ships six control/result pairs generated from held-out clips, plus a portrait fire example. Recommended settings from the card: 121 frames, resolution in multiples of 64, 24/25/50 fps, LTX 2.5 22B distilled transformer at 8 steps, CFG 1, LoRA strength 1.0.

Using it in ComfyUI

The author published an example workflow that paints both keyframes inside ComfyUI, so you can test the loop without touching an external paint tool first:

Two input frames, ainvfx-fluid_first_frame.png and ainvfx-fluid_last_frame.png, are bundled next to the workflow on Hugging Face if you want to reproduce the smoke plume sample exactly.

For real shots, the intended pipeline is compositing: generate the fluid plate against black, then screen or add it over your live footage. Because the control is just painted keyframes, art direction stays in your hands: the blob's silhouette decides where the smoke goes, and its colour tints the result.

Availability

• LoRA: AInVFX/ainvfx-fluid on Hugging Face (free, LTX-2.x Community License, same terms as LTX 2.5)
• Works with the LTX 2.5 22B transformer, dev or distilled
• Trigger word: ainvfxfluid