Object swap replacement — same plate, different object, airtight comparison

What the technique is

One source plate. A locked camera, a held subject, a stable environment. Inside the plate, one object is masked. A cloud edit pass rewrites only the masked region with a new object, holding everything outside the mask pixel-for-pixel. Cut the original to the swapped version — the only thing that has moved is the object inside the mask.

The discipline is the mask. A tight mask keeps the lighting, the ground contact, and the surrounding context unchanged. A loose mask lets the cloud pass drift onto adjacent pixels and the comparison falls apart.

When to use it

Any time a side-by-side comparison would normally need a second shoot, a second model, or a second product on set. The swap eliminates that overhead. Before/after pairs, choice-frame montages, alternate-version reveals.

How Hybrig encodes it

The Object swap replacement workflow template in /studio drops three inputs and a compositor on the canvas: the source plate, the swap mask, and a prompt that describes the new object and the hold constraints (same lighting, same shadow contact, no other changes). The Remotion compositor stitches the original and the swapped frame into a two-cut comparison.

Object swap is metered cloud work today. One pass per swap, one job at a time (per [[feedback_no_batch_paid_jobs]]). This is cloud polish, not a farm engine. Use it for the one or two beats per spot where the comparison IS the story — do not run it on every still in the timeline.

The render-process workflow

Five steps run in order. The before plate and the after plate both flow into the assembly stage so the swap transition can interpolate frame-accurately between them.

Step 1 — Source plate (before)

Node: image-upload for a real photo, or flux-lora-still for a generated source. In: a still (or short video clip via video-upload for a held shot) where the to-be-swapped object is in place. Out: the before plate — the version the audience sees first. Why: the swap only reads as a swap if the audience first sees the original. The before plate is the baseline that makes the change legible.

Step 2 — Object mask

Node: not yet a dedicated palette node — see open questions. Today the object silhouette is keyed by hand with a margin of a few pixels so the cloud edit has room to render shadow and ground-contact correctly. In: the before plate plus the object silhouette. Out: an alpha mask describing which pixels the replacement pass is allowed to rewrite. Everything outside the mask is held identical between before and after plates. Why: the single-variable-change read — the entire emotional payoff of the technique — depends on the audience confirming that nothing outside the swapped object changed. The mask is what enforces that.

Step 3 — Object-replacement cloud edit

Node: not yet a dedicated palette node — see open questions. Today the replacement pass is a manual cloud handoff. In: the before plate plus the object mask plus a prompt describing the replacement object (colors, make, model, branding constraints if any). Out: the after plate — identical to the before plate outside the mask, with the replacement object painted inside the mask. Why: one cloud edit per spot. Single-variable swaps are by definition once-per-beat. Run as a single job, never batched, per [[feedback_no_batch_paid_jobs]] — metered cloud compute gets billed by the second.

Step 4 — Transition assembly

Node: remotion-timeline. In: the before plate, the after plate, and a transition parameter (single hard cut, 12-frame cross-dissolve, frame-swap on a music sting). Out: a clip where the before plate holds for the opening beat, the transition lands, and the after plate holds for the closing beat. Why: Remotion owns the assembly. The transition choice carries the dramatic register — a hard cut feels like a switch flipping, a slow dissolve feels like a quiet transformation. Both have their place depending on the script.

Step 5 — Encode and emit

Node: video-output. In: the assembled transition clip from step 4. Out: an MP4 on disk tracked in /operations. Why: terminal node.

Studio workflow shortcut

The object swap replacement template is not yet a one-click entry in the /studio palette — the mask + replacement-edit stage is a manual cloud handoff today. Once the mask and object-replacement nodes land (see open questions), the template will live at /studio?template=object-swap-replacement and drop the full chain onto the canvas in one click.

Example use cases

• Fashion before/after. Model holding a pose in front of the same backdrop. Swap one garment for another. The lighting and the body silhouette stay identical — only the clothing changes.
• Car restoration content. Same driveway, same angle, same time of day. The original car gets swapped for the restored version. The driveway, the light, the surroundings prove the comparison is real.
• Room makeovers. Same interior plate. Swap one piece of furniture — sofa, rug, art — for an alternate. The lighting and the rest of the room hold so the audience reads each option as the same space, not a different room.
• Service-business exclusivity. Same driveway, same time of day. Cut from one contractor’s truck on the pad to another contractor’s truck on the same pad. The plate is the territory; the swap is the brand argument.