ITAI 1370 — AI History, Theory & Platforms

End-of-Year Portfolio — Cesar Zaldivar | May 2026

Module 4 — Week 4

Assignment A04: What is Raytracing?

Assignment TypeAssignment — Technical Analysis
TopicRaytracing rendering technique and real-world applications

Summary

Raytracing is a rendering technique used to generate an image by tracing the path of light as pixels in an image plane and simulating the effects of its encounters with virtual objects. Unlike traditional rendering (rasterization), which projects 3D polygons onto a 2D screen, raytracing mimics the way light works in the real world — but in reverse: it “shoots” rays of light from the camera into the scene (NVIDIA Developer, n.d.).

How It Works

StepDescription
1. Primary RaysA ray is sent from the viewpoint through each pixel on the screen
2. IntersectionThe computer calculates where that ray hits an object in the 3D environment
3. Secondary RaysReflections, refractions, and shadows are calculated by bouncing more rays toward light sources
Raytracing diagram showing primary and secondary rays Classic raytracing light path diagram

Real-World Examples

Example Application Why Raytracing Matters
Cyberpunk 2077 Real-time Lighting Path Tracing creates incredibly realistic neon reflections on wet city streets
Toy Story 4 Offline Rendering Pixar used complex raytracing for intricate reflections in the antique store scenes
IKEA Catalog Interior Design Over 75% of catalog images are 3D renders using raytracing, not real photographs
Minecraft RTX Education / Tech Demo Shows the stark difference between flat lighting and realistic light bouncing

Puzzle P04: QR Codes, Barcodes, and Augmented Reality

Assignment TypePuzzle — Research & Web Development
TopicQR Code history, comparison with barcodes, and AR applications
Live Websitemodule04-zaldivarcesar-itai1370.netlify.app

Summary

A QR code is a two-dimensional matrix barcode that stores information both horizontally and vertically. The QR code system was developed in the 1990s by engineers at DENSO WAVE (affiliated with Toyota), led by Masahiro Hara, to address the growing limitations of traditional barcodes in automotive manufacturing. Traditional barcodes could store only about 20 alphanumeric characters, which was insufficient for complex multi-site production tracking.

QR Code vs Barcode side-by-side comparison QR code example

QR Codes vs. Barcodes

Feature Barcode (1D) QR Code (2D)
Data Capacity Low (~20–25 characters) High (thousands of characters)
Dimensions Horizontal only Horizontal and Vertical
Error Correction None — unreadable if damaged High — readable even if 30% is damaged
AR Utility Limited Excellent — spatial anchoring for AR overlays

What I Learned

Raytracing fundamentally changed how we create photorealistic digital images, and GPU advances have now made real-time raytracing accessible in consumer video games. The IKEA example was especially eye-opening — most people assume catalog images are photographs, but the majority are computer-generated renders.

Building a website to present the QR code research was one of the most hands-on experiences of the semester. I learned that QR codes are far more sophisticated than they appear, with built-in error correction and spatial orientation features that make them ideal for augmented reality anchoring. You can visit my live site at module04-zaldivarcesar-itai1370.netlify.app.

Citations

NVIDIA Developer. “Ray Tracing.” NVIDIA, n.d., https://developer.nvidia.com/discover/ray-tracing.

DENSO WAVE. “QR Code Development Story.” DENSO WAVE Technologies, n.d.