Six things: the aspect ratio, the cast, the locations, the look, the negative prompt set, and the delivery resolution. Three of those are genuinely irreversible once a chain starts — aspect ratio and resolution are inherited by Edit, Extend and Motion with the selector hidden, and a cast you've written six episodes around is expensive to recast. Locking them costs nothing now.
The useful distinction isn't between important decisions and unimportant ones. It's between decisions you can revisit and decisions that quietly close behind you.
Why does locking matter more here than on a shoot?
Because the thing that normally enforces consistency is missing.
On a set, continuity is physical. The room is the room, the light is where you left it, the actor is the same person. You don't lock those because they can't drift.
In generation, nothing is held unless you hold it. Each pass is independent and the model has no memory of the previous one, so every fact about your world has to be restated or re-attached — or it gets reinvented.
Locking is the substitute for physical continuity. It's not a discipline for tidy people; it's the mechanism.
On a set, the room can't drift. In generation, nothing is held unless you hold it.
What are the six, and which are irreversible?
Ordered by how expensive they are to change after you've started.
| Lock | Reversible? | Why |
|---|---|---|
| Aspect ratio | **No** | Edit, Extend and Motion all inherit it from the source and hide the selector. It's decided in the first Create generation and can't be revisited downstream |
| Delivery resolution | **No, within a chain** | Extend inherits resolution from the source too. It's also plan-gated, so what you can deliver depends on your tier as well as the model |
| The cast | Expensive | Recasting after episodes are written is a visible break. A saved reference can be regenerated; a cast decision written into six scripts can't |
| The locations | Cheap to lock, moderate to change | Regenerating a location reference is one action. Every prompt that described the place instead is a separate edit |
| The look | Cheap to lock, moderate to change | Same shape as locations. A style reference changes once; a re-described treatment changes everywhere |
| The negative prompt set | Free | Append it unchanged every time. Rewriting it per shot is a source of variation you didn't intend |
Source: Hexcoded Creative Studio documentation and pricing page, checked September 2026, plus established production conventions.
Where this falls short. The two irreversible ones are irreversible within a chain, not forever. You can always start a new Create generation at a different aspect ratio — you just can't reframe the chain you've built. Which for a scene assembled through Edit and Extend amounts to the same thing.
Why is the aspect ratio the one that catches people?
Because it feels like a formatting decision and behaves like a structural one.
Create mode offers seven aspect ratios with 9:16 as the default. Edit, Extend and Motion each inherit it from the source clip and hide the selector entirely — there's nothing to change even if you want to.
So a scene built by generating, then editing, then extending has its framing fixed by the first of those three actions. And if a project needs both a vertical and a landscape cut, that's two chains from two Create generations rather than one chain reframed at the end.
Nobody discovers this in advance. It shows up when someone asks for a 16:9 version of something you built vertically.
Aspect ratio looks like formatting and behaves like structure. Decide it in the first generation.
How do you lock the cast, locations and look?
By saving them, not by writing them down.
Each becomes a reference in your library with an @handle — lowercase, digits, dashes or underscores, unique to your workspace. You call the handle in any prompt, in any tool, instead of describing the thing again.
That distinction matters more than it sounds. A description written into a document and pasted into prompts still varies, because people paraphrase, tidy and improve. A saved reference doesn't vary, because there's nothing to retype.
The reference types cover all three: characters, locations, styles, plus elements for recurring objects and props. Each also takes an optional description field of up to 200 characters, which is where to note what the thing is and what created it.
What about the negative prompt set?
Lock it and never rewrite it.
The standard set for series work covers face swaps, wardrobe changes, broken hands, floating props and camera jumps. Appending it unchanged to every prompt is the whole technique.
The reason not to rewrite it per shot is the same reason not to re-describe a character: variation you didn't intend. A negative set that's slightly different on shot four than shot three is introducing exactly the inconsistency it exists to prevent.
no face swaps, no wardrobe changes, no broken hands, no floating props, no camera jumps
Standard negative set for series work. Append unchanged rather than rewriting per shot.
What shouldn't you lock?
Three things, and locking them early is a common mistake in the other direction.
The model, per shot. One balance covers every model on the roster, so choosing per shot costs a decision rather than a subscription. Committing to one model for a whole project throws that away.
The shot list, in detail. Lock the scene and the beat. Leaving the exact coverage open means you can respond to what the first generations actually produce, which is usually better than what you planned.
The performance. How a line lands is worth discovering rather than specifying. Over-directed prompts tend to produce stiffer results than looser ones.
What's the actual order?
Six steps, and the first two take minutes.
Decide the aspect ratio and the delivery resolution
Both are inherited downstream and both are plan-gated. Two minutes now, or a regeneration later. If you need two aspect ratios, plan for two chains.
Check what your plan actually permits
Resolution ceiling and model access are both tiered. A deliverable you can't produce is worse than one you decided against.
Create and save the cast
Each actor once, with a handle. Test profile and mid-turn before any script depends on the face.
Save the locations and the look
Every recurring place and the visual treatment, each as a reference with a handle. Recurring objects too, as elements.
Fix the negative prompt set
Write it once, append it unchanged. Rewriting it per shot is self-inflicted variation.
Then write the shot list, and leave the coverage loose
Scene and beat locked, exact shots open. The first generations will tell you things the plan couldn't.
- Locking is the substitute for physical continuity. Nothing is held in generation unless you hold it
- Aspect ratio is the one that catches people. Edit, Extend and Motion inherit it and hide the selector
- Two aspect ratios means two chains from two Create generations, not one reframed at the end
- Resolution is inherited in Extend and gated by plan. Decide the deliverable before you start
- Save the cast, locations and look as references with handles. A saved reference can't drift; a pasted description can
- Lock the negative prompt set and append it unchanged. Rewriting it per shot is variation you didn't intend
- Don't lock the model. One balance covers the roster, so choose per shot
- Don't lock the coverage. The first generations will tell you things the plan couldn't
Six things: aspect ratio, delivery resolution, the cast, the locations, the look and the negative prompt set. The first two are inherited downstream and can't be changed within a chain, and the middle three are cheap to lock and expensive to change once footage exists.
Edit, Extend and Motion all inherit it from the source clip and hide the selector entirely. Only Create lets you choose. So framing is fixed by the first generation in a chain, and a project needing two aspect ratios needs two chains.
Save it as a reference with a handle and call the handle in every prompt rather than describing the character again. A saved reference doesn't vary; a description pasted from a document does, because people paraphrase and tidy it.
Yes, and lock it. The standard set for series work covers face swaps, wardrobe changes, broken hands, floating props and camera jumps. Append it unchanged rather than rewriting it per shot, since a set that varies introduces the inconsistency it exists to prevent.
The model, the detailed coverage and the performance. One credit balance covers every model, so choosing per shot costs a decision rather than a subscription. And leaving the coverage loose lets you respond to what the first generations actually produce.
Profile, backlit and mid-turn. Those break first and in that order. Three test generations cost far less than rewriting episodes around a face that only holds front-on.
Lock it once, call it everywhere
Save your cast, locations, styles and props as named references, each with a handle that works in every tool. Aspect ratio and resolution are visible per model before you generate — which is the right time to decide them.
Open Creative StudioMore on workflow, continuity and shot planning in Production.