LTX 2.3 Sulphur 2 Prompt Relay Workflow in ComfyUI | Image2Video Motion Control

Turns still images into cinematic motion-controlled videos instantly.

Who it's for: creators who want this pipeline in ComfyUI without assembling nodes from scratch. Not for: one-click results with zero tuning - you still choose inputs, prompts, and settings.

Open preloaded workflow on RunComfy

Open preloaded workflow on RunComfy (browser)

Why RunComfy first
- Fewer missing-node surprises - run the graph in a managed environment before you mirror it locally.
- Quick GPU tryout - useful if your local VRAM or install time is the bottleneck.
- Matches the published JSON - the zip follows the same runnable workflow you can open on RunComfy.

When downloading for local ComfyUI makes sense - you want full control over models on disk, batch scripting, or offline runs.

How to use (local ComfyUI)
1. Load inputs (images/video/audio) in the marked loader nodes.
2. Set prompts, resolution, and seeds; start with a short test run.
3. Export from the Save / Write nodes shown in the graph.

Expectations - First run may pull large weights; cloud runs may require a free RunComfy account.

Overview

This setup helps you turn static images into cinematic video clips enhanced by motion-aware prompts. It combines LTX 2.3 video generation with Sulphur 2 motion control for smoother transitions and lifelike camera moves. With segmented prompt sequencing, you can define micro-actions for each moment. It supports realistic lighting, expressive movement, and scene continuity. The system provides an efficient path to transform images into professional-level cinematic storytelling sequences.

Important nodes:

Key nodes in Comfyui LTX 2.3 Sulphur 2 Prompt Relay workflow

• PromptRelaySmartEncode (#610)

• Purpose: Translates your beat‑by‑beat “smart prompt” into properly timed text conditioning for the whole clip. Use global_prompt for unchanging details (style, subject, lighting) and smart_prompt for the action sequence. Two authoring styles are supported: inline segments separated by | with optional proportional tags like [0-50], or block headers like “Scene 1:” that weight segments by range. Keep one syntax per prompt to avoid ambiguity. Reference: ComfyUI‑PromptRelay.

• LTXVImgToVideoInplaceKJ (#617)

• Purpose: Locks the first frame’s look and gently propagates it through motion. If identity or wardrobe drifts, raise its image adherence; if motion seems constrained, lower it to allow more dynamics. Balance this with your Sulphur 2 LoRA strength so the reference remains stable without over‑freezing motion.

• LoraLoaderModelOnly (#628) — Sulphur 2 motion LoRA

• Purpose: Injects the Sulphur 2 fine‑tune to bias motion continuity, trajectory smoothness, and action staging. Increase strength_model to emphasize guided movement across segments; reduce it if you see over‑constraint or repeated patterns. Adjust in tandem with ImgToVideoInplace strength to keep subject fidelity and motion energy in harmony.

• LTXVConditioning (#164)

• Purpose: Consolidates positive/negative conditioning for LTX‑2.3 and sets the clip’s frame rate. If you lengthen the shot, revisit your Prompt Relay segment weights so the relative timing still matches the intended beats.

• SamplerCustom (#561)

• Purpose: Runs the denoising pass using your chosen sampler and schedule. If motion is jittery, try a slightly smoother schedule or a sampler known for temporal stability; if prompts under‑steer, modestly raise guidance while watching for over‑saturation. Use VisualizeSigmasKJ to sanity‑check the schedule’s shape before long runs.

Notes

LTX 2.3 Sulphur 2 Prompt Relay Workflow in ComfyUI | Image2Video Motion Control - see RunComfy page for the latest node requirements.