macOS · Custom Metal engine · 4K/60 export · Notarized DMG · Invite-only alpha · fob.sh/dolly
Dolly
A cinematic render studio for product shots, built on a search-and-rescue engine.
Dolly is a native macOS render studio for cinematic product shots and device mockups. Drag media onto a procedurally generated 3D iPhone, compose the shot with a free-fly camera and studio lighting, pick a scene — Rainy Night, Lakeside Dusk, Northern Lights — keyframe a camera move, and export publication-ready 4K video or a full App Store screenshot batch. Everything renders in real time on the user's own Mac. The visuals on this site were rendered in it.
- Swift
- Metal shading language
- Custom render pipeline (no SceneKit/Unity)
- AppKit + SwiftUI
- AVAssetWriter (H.264/ProRes)
- Swift Package Manager
- Developer ID + notarization
- License activation
Origin
How it started
The first App Store screenshot submission for PayCheck Budget was a disaster — wrong pixel sizes, rejected uploads, hours gone. Every product since paid the same tax: screenshots into device frames into color grading into exports, across four different tools. Dolly collapses that workflow into one app. The unfair advantage was already on disk: RANKAN's search-and-rescue work had produced a custom Metal engine for rendering 100M+ LiDAR points at 60fps. Pointing that engine at product marketing instead of point clouds took 34 hours from first commit to a notarized v0.3.0.
Features
What it does
Procedural 3D device studio
An iPhone body generated in code — rounded edges, lens stack, buttons, antenna lines — in 18 finishes from Silver to Titanium plus a custom color wheel. Studio image-based lighting with a user-editable rig: key light azimuth, height, power, and color, plus ambient and rim. Floors in polished studio, traveling water waves, or dune sand.
Eight cinematic scenes
Studio, Rainy Night, Campfire, Lakeside Dusk, Winter, Desert Dawn, Deep Space, and Northern Lights — each a full atmosphere: volumetric fog, billboarded rain streaks with wet-floor darkening, ember and snow particles, starfields and aurora. Neon practical lights with mirrored floor reflections for the synthwave look.
Keyframed camera moves
A 6-DoF free-fly camera with quaternion math, orbit, pan, and floor clamping. Save poses with ⌘K, then play eased spline paths that auto-frame so the device never crops. Five move templates ship in the box: Orbit 360, Push In, Rise & Reveal, Hero Arc, and a scale-preserving Dolly Zoom.
Drop video, not just stills
Screen recordings loop directly on the 3D device's screen with smart fit modes and auto-rotate for landscape content. A cinema mode throws the demo onto a curved jumbotron stage with theater dressing — per-keyframe field of view makes real dolly-zoom moves possible.
One-click App Store batch export
The feature the whole product started from: exact-size presets for every screenshot dimension Apple accepts, exported in one batch with per-aspect auto-reframe. Plus 4K/60 H.264 video (⌘R), 4x PNG stills (⌘E), and transparent PNGs (⇧⌘E) that skip post-effects and render overlays at 4x MSAA.
Real post pipeline
Depth of field driven by circle-of-confusion from the resolved depth buffer, bloom from a half-res bright pass with separable blur, SSAO, temporal motion blur in video exports — 4 subframes at a 0.6× shutter, with particle streaking. Draggable multi-text overlays composite after DOF so titles stay sharp.
Headless scripting
Environment-variable scripting drives scene, device, media, text, and camera move for unattended renders — the product's own marketing showreel is produced by Dolly running headless. The tool ships its own ads.
Under the hood
Engineering
A rescue engine repurposed
The renderer began as RANKAN's LiDAR point-cloud engine — built to draw 100M+ points at 60fps for search-and-rescue scanning. Dolly extracted that engine (27 source files, triple-buffered, with device-capability detection) and pointed it at product cinematography. Separate render paths for A16-class iPhones and M-series Macs survive from the original engine, so the pipeline scales to the GPU it finds.
Fully custom Metal, no engine dependency
No SceneKit, no RealityKit, no Unity. The pipeline is hand-built: 4x MSAA color and depth, resolve to texture, half-res bright pass, separable blur, then a DOF-plus-bloom composite using circle-of-confusion from resolved depth. Anisotropic filtering with LOD bias kills moire on the device screen texture; film-grain dither prevents gradient banding in the sky pass. 18,000 lines of Swift and Metal shading language.
Three releases in 34 hours
First commit June 9, 2026. v0.1.0, v0.2.0, and v0.3.0 all shipped by the night of June 10 — 47 commits, a Developer ID-signed, hardened-runtime, notarized and stapled DMG, license activation with offline grace, and a tester program recruited the same night. The velocity is the point: an engine that already existed plus AI-assisted assembly let a one-person studio ship a real graphics product in a weekend's worth of hours.
What's possible
The studio that shoots the rest of the portfolio
Dolly is infrastructure for everything else Nathan ships: every future app gets cinematic App Store screenshots, launch videos, and press assets rendered locally in minutes instead of contracted out. Roadmap work includes live window capture via ScreenCaptureKit, custom USDZ device models, and PBR materials — but the alpha already pays rent: this portfolio's hero footage came out of it.