Portal Cuts: Every Transition Opens Through Something Real

Primary effect: Bring your own effect – Shape-Matched Portal Transitions (custom shaders + alpha-matte shapes)

Five cuts in this train journey open through something that's actually in the shot: a train door, a rushing locomotive, a tunnel mouth, the arches of the Nine Arches Bridge, and the side of a moving train. The next clip plays inside that shape, then the camera pushes straight through into the new scene.

Built in invideo Editor using invideo's MCP connection with Claude. Claude read my timeline, captured frames, measured each shape and wrote every transition as a custom GLSL shader with editable controls, directly on my invideo timeline. No rotoscoping, no tracking, no other editor.

PROCESS NOTE

Starting footage: 7 vertical clips of train journeys (door view of the ocean, coast road from the window, beach railway, tunnel, Nine Arches Bridge, palm-side train, tea estate) plus a Pixabay music track, uploaded to invideo Editor.

What I asked the agent: I connected invideo's MCP server to Claude and directed it cut by cut: "turn the inside of this door into a portal", "use the real shape of the tunnel hole, not a rectangle", "open all the arch gaps under the bridge", "make the train body the portal, not the sky", "add the same effect to the locomotive". For each one it captured timeline frames, measured the shape and wrote a custom shader transition on the cut: the next clip appears inside the shape, plays, then the camera pushes through. Moving shapes (the approaching locomotive, the drone drift on the bridge) are keyframed, not tracked.

What I refined: I removed the warm glow on the tunnel, rejected versions that didn't look right (a sky cut-out and a floor-drop portal) and had them rebuilt, re-ordered the edit to open on the door shot, swapped in a new clip, and adjusted edge softness, push-through timing and scale using the controls the agent created. After exporting the final MP4 from invideo, I upscaled it with Topaz Astra 2.

LINKS

invideo timeline: https://invideo.io/share/Portal-Cuts-invideo-a2gooqayNEE Instagram post: https://www.instagram.com/reel/DeThWD-SydB/?exln=cDlvNzBucmpvaWps

@invideo.io #invideocontrachallenge #invideoeditor

invideo Editor is free to try.