Realtime Previs Toolkit — Aditya Manikashetti

The toolkit grew out of frustration with existing previs software that required a dedicated workstation and a specialist operator. The goal was a tool that a director or DP could run on a tablet on set, with no installation and no licensing cost. It runs entirely in the browser using WebGL and a lightweight scene graph written in TypeScript. Camera data feeds in over WebSocket from a tracker mounted on the physical lens.

The scene library covers the most common production scenarios: interior rooms, exteriors with a configurable sun position, and a neutral grey void for abstract blocking work. Geometry is low-poly by design. The point is not photorealistic preview but spatial understanding — knowing where the camera is relative to the actor and what the frame will contain at a given focal length.

Overhead schematic view of a room with camera and actor markers — Plan view — camera blocking interface

First-person camera preview with focal length controls visible — Camera POV — 35mm equivalent, 1.78:1

The WebSocket layer connects to a small Rust daemon that reads serial data from the tracker and broadcasts it over a local network. Latency from physical lens movement to viewport update is under 30ms on a standard office Wi-Fi connection. The tracker protocol is documented in the repository under /docs/tracker-protocol.md.