同一個角色，首次生成時穿著藍色外套站在咖啡廳門口，點了重新生成卻變成紅衣服出現在街角。光線、構圖、甚至臉型都不太一樣。這不是模型出錯，是兩條流程根本沒在同步。
就像兩個廚師用同一份食譜，一個看的是最新版，另一個還在用三個月前的舊版本。客人點同一道菜，吃到的味道當然不一樣。
空間定位才是真正的關鍵
多數人以為固定 seed 值、寫清楚「maintain the same character」就夠了，但最容易被忽略的其實是空間描述。提示詞裡少了「in the foreground」「behind the desk」「at the center of the room」這類定位資訊，AI 就會隨機安排元素位置。
有經驗的工程師會在三個層次同步處理：劇本的場景描述、場景提取的結構化資料、最終視覺提示詞。缺任何一環，構圖就會天差地別。這不是寫一次 prompt 的問題，是整條資料流都要保持空間資訊的傳遞。
單邊更新的陷阱
問題通常出在這裡：團隊優化了首次生成的邏輯，加了新的一致性檢查、調整了提示詞模板，但重新生成的流程還在用舊版本。兩條路徑可能寫在不同檔案、不同模組，負責的人也不同，沒人記得要同步更新。
使用者的體驗就是：第一次生成品質不錯，重新生成就炸掉。角色外觀變了、光線風格消失了，甚至連原本設定好的空間關係都亂掉。
技術上的解法是程式碼重構，把共用邏輯抽出來。但更實際的做法是建立檢查清單：任何 prompt 邏輯的變動，都要確認是否影響到其他生成路徑。聽起來很基本，但就是這種基本的東西最容易漏。
其他值得注意的細節
從第三方服務遷移到官方 API 時，模型名稱、base64 編碼格式、錯誤處理機制都可能不同。Shell 環境中的 bcrypt 雜湊值裡有 $ 符號，沒用引號包起來會被當成變數解析，密碼就對不上了。
這些不是什麼高深技術，就是容易被忽略的實作細節。視覺一致性的問題，最後往往不是出在模型本身，而是流程之間沒對齊。
— 邱柏宇
Same character. First generation: blue coat, standing at the café entrance. Hit regenerate: red clothes, appears at a street corner. Different lighting, different composition, even the face looks off. The model didn’t break—the two workflows just aren’t synced.
Like two chefs using the same recipe, except one has the latest version and the other is still using the draft from three months ago. Same dish ordered, different taste delivered.
Spatial Positioning Is the Real Key
Most people think fixing the seed value and writing “maintain the same character” is enough. What actually gets missed is spatial description. Without positioning phrases like “in the foreground,” “behind the desk,” or “at the center of the room,” the AI just randomly arranges elements.
Experienced engineers synchronize across three layers: scene descriptions in the script, structured data from scene extraction, and the final visual prompts. Miss any layer and your composition falls apart. This isn’t about writing one prompt—it’s about maintaining spatial information throughout the entire data pipeline.
The Single-Side Update Trap
Here’s where it breaks: the team optimizes initial generation logic, adds new consistency checks, refines prompt templates—but the regeneration workflow still runs the old version. Two code paths in different files, different modules, handled by different people. Nobody remembers to sync.
User experience: first generation looks good, regeneration breaks. Character appearance changes, lighting style vanishes, even the spatial relationships you configured get scrambled.
Technical fix is code refactoring—extract shared logic. More practical approach: create a checklist. Any prompt logic change must be verified across all generation paths. Sounds basic, but basic stuff is exactly what gets missed.
Other Details Worth Noting
Migrating from third-party services to official APIs means different model names, base64 encoding formats, error handling mechanisms. Bcrypt hashes in Shell environments contain dollar signs—without proper quoting they get parsed as variables, and your password verification fails.
None of this is advanced technology. Just implementation details easy to overlook. Visual consistency problems usually don’t come from the model itself—they come from misaligned workflows.
— Jett Chiu