The core prompt pattern
A strong X2 prompt follows this pattern:Change only the central person’s jacket to the outfit in the reference image. The clothing follows the body naturally. Preserve the face, hair, motion, background, and camera.The ideal prompt is the shortest instruction that clearly establishes:
- Target: the exact subject, object, garment, or region being controlled
- Change: one dominant visible transformation or action
- Relationship: contact, direction, tracking, or motion behavior
- Boundary: the important parts of the source that must remain stable
Stable capability prefixes
X2 supports free-form prompts, but its model guide recommends exact Chinese prefixes for its reference-guided capabilities. Keep the prefix verbatim and place the scene-specific instruction on the following line. The prefix is prompt text, not a separate API mode.| Intent | Stable prefix | Inputs | Scope |
|---|---|---|---|
| Character replacement | 视频中角色替换成参考图中角色 | Source video and character reference | Character only |
| Clothing replacement | 视频中人物衣服替换成参考图中衣服 | Source video and clothing reference | Clothing only |
| Style transfer | 视频风格变为参考图指定的风格 | Source video and style reference | Character, clothing, and background |
| Trajectory animation | 让画面自然动起来 | Still or video source and control signal | Motion |
| Dimension interaction | 指定角色在场景中互动 | Camera source and character reference | Adds an interactive character |
| Free prompting | No prefix | Source; reference optional | Effects, objects, backgrounds, and transformations |
Instructions, not keyword lists
The source already contains the subject, setting, framing, lighting, and motion. Prompt the change, not a new scene from scratch.Make this magical, cinematic, epic, dramatic, high quality.
A burning crystalline fireball materializes in the person’s open right palm and sheds sparks as the
hand moves. Preserve the person’s face, clothing, room, and camera.
The stronger version names a visible result, anchors it to a precise location, explains how it
behaves, and defines a boundary. Additional style adjectives would not make it more controllable.
Character replacement
Use one clear reference image for the target character. The source person’s expressions, gaze, pose, and movements become the performance that the new character follows.Clothing replacement
The clothing reference can show a garment against a clean background or a person wearing the target outfit. Use the clothing prefix whenever identity, face, and hair must stay unchanged.Whole-scene style transfer
Style transfer intentionally permits the subject, clothing, and background to change together. The reference image carries the visual vocabulary; the prompt defines scope and continuity.Dimension interaction
Dimension interaction introduces a reference character into a live physical scene and lets it respond to people or objects already there.- Start against a plain background.
- Avoid human faces while the reference character is first forming. Otherwise, the character may be mapped onto a person already in the frame.
- Let the generated character stabilize before people enter and interact with it.
- Describe one interaction with a hand, surface, or environmental object.
Free prompting
Free prompting covers effects, object replacement, background changes, and transformations that do not need a capability prefix. Favor a concrete result state anchored to a visible body part or source object. EffectA burning fireball appears in the right palm. The flame and sparks follow the hand. Preserve the face, clothing, room, and camera.Object replacement
Replace the white plush ball in the left hand with a cute kitten. Keep natural contact with the hand. Preserve the person and background.Body-anchored effect
Bright red lasers extend from both eyes and follow the direction of the gaze. Preserve facial identity, body, background, and camera.Concrete result-state language such as “a fireball is in the person’s palm” is usually stronger than abstract direction such as “make the scene feel powerful.”
Drag and trajectory control
For trajectory-controlled generation, the prompt names what follows the trajectory and the control signal supplies where it moves.- Start directly on the intended subject or body part.
- Drag slowly along a broad, smooth path.
- Hold the endpoint briefly before release so it survives the model’s chunk cadence.
- Expect the generated output to lag behind the physical pointer.
Drag state is not prompt state
The active prompt persists while generation runs. If it says that petals “continuously fall,” the model can keep producing that motion even after the drag signal disappears. Temporal phrases such as “while dragging” and “when released” do not turn a persistent instruction into a guaranteed press-and-release state machine.While the drag is held, cherry blossom petals continuously fall from the sky. When the drag is
released, the falling stops.
Only the cherry blossom petals follow the active drag trajectory. Their movement is caused
exclusively by the control point. With no control point, the petals remain still. The sky, branches,
camera, and everything else remain fixed.
The stronger prompt removes the unconditional visual instruction “continuously fall” and binds the
petals’ movement to the control signal. It improves the behavior, but it still does not provide
strict application logic.
When exact hold-and-release behavior matters, switch the complete prompt with the input state:
| State | Prompt |
|---|---|
| Pointer down | Cherry blossom petals fall and follow the active drag trajectory. Everything else remains fixed. |
| Pointer up | The cherry blossom petals are motionless. The entire scene is still. |
Choosing source and reference inputs
Prompt quality cannot compensate for an ambiguous source or reference. Source video- Keep the controlled subject large enough to identify and away from the frame edge.
- Prefer stable framing and slow or moderate motion.
- Make clothing visible for clothing replacement and expressions visible for character replacement.
- Preserve the source aspect ratio before the session begins. Cropping and resolution negotiation are media-pipeline concerns, not prompt problems.
- Use one isolated, readable subject whenever possible.
- Use the reference for appearance and the prompt for behavior and relationships.
- Match the desired viewing angle and framing when identity or garment structure matters.
- Do not spend the prompt exhaustively redescribing details already visible in the reference.
An iteration ladder
Start short. Add detail only to solve a visible failure:- Send the stable capability prefix.
- Add the exact target and transformation.
- Add one motion or physical-relationship clause.
- Add one preservation boundary.
- Reduce motion in the source. Fast source motion makes prompt alignment harder.
- Wait longer. Some transformations take several generation chunks to become visible.
- Rephrase the target and action with more concrete nouns and verbs.
- Generate again. X2 has some run-to-run variation.
Troubleshooting
| Failure | Best correction |
|---|---|
| Nothing changes | Use a stronger visible action, slow the source, wait, then retry |
| Wrong person changes | Name position, clothing, or another visible discriminator |
| Too much of the frame changes | Use a narrower capability prefix and add one preservation boundary |
| Character identity is weak | Improve the reference instead of lengthening the prompt |
| Clothing replacement changes the face | Use the clothing prefix and explicitly preserve face and hair |
| A summoned character maps onto a person | Begin with a plain, face-free source until the character settles |
| Drag motion jitters or misses the endpoint | Slow the path, simplify the subject, and hold the endpoint briefly |
| Background moves during drag | Name the controlled subject and explicitly fix the background and camera |
| An effect continues after release | Remove unconditional motion language or switch prompts with the input state |
| The frame is cropped | Fix the source canvas or session aspect ratio; prompting cannot restore pixels |
Common pitfalls
- Several edits in one prompt. Character replacement, wardrobe change, style transfer, and a background swap compete. Choose one dominant transformation.
- A vague target. “Make it move” is ambiguous. Name the red paper glider, the left person’s jacket, or the white ball in the hand.
- Pronouns in a crowded frame. Spatial descriptions are more reliable than “him,” “her,” or “it.”
- Keyword piles. “Cinematic, epic, magical, 8K” does not define a controllable edit.
- Long negative lists. Name the important preservation boundary instead of cataloguing every forbidden change.
- Multi-stage stories. “First this happens, then…” is harder to sustain than one visible action or result state.
- Describing the reference twice. Let the reference supply appearance; use the prompt for its role in the source scene.
- Treating the pointer as a button. It provides spatial conditioning, not guaranteed event semantics.
- Relative mid-stream instructions. A new prompt replaces the active prompt. Restate the whole instruction rather than saying “make it more dramatic” or “stop that.”
The one-sentence rule
When in doubt, use this structure:One exact subject performs one visible action or transformation, with one physical relationship and one preservation boundary.That sentence is usually a better starting point than a long cinematic description. Add detail only when a specific failure shows you what the model still needs to know.