NormalMap AI

Free Normal Map Generator & seamless, tileable PBR texture.

May 12, 2026 Building a Free Browser-Based PBR Texture Generator (No Plugins, No Uploads)

I built NormalMap AI — a free, browser-based tool that generates complete PBR texture sets (Normal, Roughness, AO, Metallic, Height, ORM) from any uploaded image. Here's what I learned building it.

The Problem

Game devs and 3D artists have always needed PBR texture maps. The traditional tools:

- Photoshop 3D filter: removed in newer versions, never great

- Substance Painter: $49.99/month per seat — a lot for hobbyists or small studios

- Free desktop tools: slow, require installs, inconsistent results

My goal: make the full PBR workflow free, instant, and browser-native.

Technical Approach

Core pipeline: WebGL compute shaders for all map generation.

- Normal map: Sobel operator on height-converted luminance, GPU-computed

- Roughness: variance + high-frequency detection across local neighborhoods

- AO: SSAO-style hemisphere sampling in screen space

- Height: multi-scale luminance integration with gamma correction

- Metallic: saturation + specular estimation from luminance

Real-time 3D preview uses Three.js + custom HDRI loader, running at 60fps.

The Seamless Texture Maker

This was the hard part. Auto seam repair uses a 3-algorithm cascade:

1. Optimal offset search: finds the best tile offset to minimize edge discontinuity

2. Min-cut seam repair: graph-cut algorithm to find the minimum-cost seam path

3. Structural patch repair + low-frequency balance: handle remaining artifacts

Plus clone and healing brushes for manual touch-up, and a delight pass to remove uneven lighting before tiling.

AI Integration

Added AI texture generation from text prompts (FLUX + other models via Runware). Users can generate a source texture from a prompt, which automatically feeds the PBR pipeline. Credit-based pricing: 5 free credits/day, paid plans from $19.90/month.

Results

- The free tier covers 90% of use cases for hobbyists and indie devs

- AI generation is where the revenue comes from

- Biggest surprise: transparent PNG maker (black + white matte removal for VFX) became a top use case I didn't anticipate

Tech Stack

- Frontend: Astro + TypeScript

- Rendering: WebGL / Three.js

- Auth + DB: Supabase

- Payments: Creem

- AI providers: Runware + Kie

Questions for IH:

1. How do you price free-tier limits to convert without annoying power users?