Cristian Díaz - elkraneo Blog

Shader

LYGIA Metal Viewer

A native viewer for the Metal port of LYGIA

Illustration of a rectangle wrapped by a three-dimensional ribbon giving the sensation of melting in reference to the dilation process for outline drawing

RealityKit

RealityKit Outline Selection

ℹ️Update (October 2026): This is now a Swift package Beyond the RealityView effect described here, it adds: * ARView support back to iOS 15 (UIKit/AppKit) via install(on:), prompted by Richard Hasson's email * outlines that follow moving entities (transforms refresh every frame, not just at selection) * multi-

Reality Composer Pro

Deconstructing Reality Composer Pro (Inspector Components ...continued)

This latest wave of fixture work extended the reverse-engineering effort across Reality Composer Pro’s built-in components. Now it's documented and implemented more fixture-backed components across Deconstructed and Uncannyuse, including Environment Lighting Configuration, Grounding Shadow, Image Based Light, Image Based Light Receiver, Virtual Environment Probe,

An open sphere in an abstract graphic represents a dome with a stage, a cube acting as the main character, and several more cubes backstage

Reality Composer Pro

Deconstructing Reality Composer Pro (Inspector Components)

The previous inspector series parts explored attributes that map cleanly to USD: transforms, material bindings, and variant sets. Components are different. One might expect that RCP's component inspector would just show RealityKit components attached to entities—the same components you'd add in code at runtime. But

Illustration of a plane with colorful stalactites and stalagmites representing the diversity that can exist in hidden places

Reality Composer Pro

Deconstructing Reality Composer Pro (Inspector Bindings, References and Variants)

The next level of functionality in the RCP inspector offers deeper control over model linking, looks, and variations Bindings In OpenUSD, the terminology "Binding" comes from the UsdShadeMaterialBindingAPI. Unlike traditional formats where a material is simply a property of a mesh, USD treats materials as independent prims that

Reality Composer Pro

Deconstructing Reality Composer Pro: Logbook

A continually growing list of interesting things found during exploration that have not yet been featured in the "Deconstructing Reality Composer Pro" series entries. Mapping from Prims to Entities RCP maintains a bidirectional mapping between RealityKit entities and USD prim paths. While public RealityKit doesn't easily

Illustration of 3x3 boxes in perspective, similar to the boxes on the transform inspector in RCP.

Reality Composer Pro

Deconstructing Reality Composer Pro (Inspector Basics)

Dual-mode Inspector: scene layer shows global stage metadata (upAxis, metersPerUnit), while prim inspection displays transform, materials, and references. UI presents cm/degrees; USD persists meters/quaternions with rotationEulerHint for round-trip editing.

Reality Composer Pro

Deconstructing Reality Composer Pro (Scene Navigator)

To implement the Scene navigator, we will need to handle .usd manipulation, and the best approach I have found is to use Apple's SwiftUsd project. Although it is a bit behind the standard and has some quirks with C++ interops, it remains powerful and convenient, and by including

Illustration of a blob melting in the center of a grill, representing a three-dimensional viewpoint.

Reality Composer Pro

Deconstructing Reality Composer Pro (Viewport)

Viewport is deep (modes, debug views, presets/history). We are going to implement just a working viewer + camera for this pass; chasing full parity will balloon scope. The main viewport is built with RealityKit, and we'll add a layer for gestures, a grid, and a simple Arcball implementation

Reality Composer Pro

Deconstructing Reality Composer Pro (Project Browser)

Part of what makes Reality Composer Pro a composer is asset management. Importing, soft validation, organizing, and iterating on the project structure are essential features to have in creative pipelines. The project browser in RCP is similar to Finder's grid view and, because of that, filled with UX

Reality Composer Pro

Deconstructing Reality Composer Pro (Document Type)

An exploration of the .realitycomposerpro document type. This post breaks down its structure as an SPM-backed package, the nested bundle system for assets, and how this layout could enable Xcode and `realitytool` processing.

Illustration with 3D perspective of a phase-layered stack of cubes ending in a dark plate with fewer elements and distribution. Tool abstraction metaphor from this article.

Reality Composer Pro

Deconstructing Reality Composer Pro (Intro)

Reality Composer Pro prioritizes the transition of elements over direct emphasis on creation and debugging tasks. It's a portal where you transport raw, wild formats to more manageable, controlled, static-defined files that can be represented on RealityKit.

Illustration of abstract figures (white cones) concentrating and melting with a central cube (purple)

RealityKit

Compiling .reality: The Technical Reality

Xcode runs a verified two-pass process to compile .reality files: first generating USD schemas from your Swift components, then compiling them into optimized bundles.

Developers should not have access to eye tracking information

...and there are strong reasons against it. The conversation could be philosophical, but it highlights the conflicting opinions on whether commercial interests should take precedence over human well-being. Also, the few potential exceptions could be handled in controlled environments using entitlements or research. What Does Your Gaze Reveal About

Art

The Aesthetics of Immersion

Synthetic environments and traditional landscape paintings

Screenshots from both apps running in Tahoe show the initial list of contents.

WWDC

WWDC25 updates to Transwwdcripts & Resourwwdces

Just updated the data source to include WWDC25 contents and recompiled for Tahoe because it is nicer... Download Transwwdcripts v1.2Download Resourwwdces v1.1TranswwdcriptsIn the spirit of ASCIIwwdc, understanding that transcripts have significant benefits for accessibility and research, creates a situation in which making text versions of talks available becomes