# Shape, Then Texture

**Track:** 3D — beginner → intermediate — Generative AI 3D — proposed
**Framework / surface:** ij8 Studio (dual-pass pipeline)
**Level:** Beginner
**Prerequisites:** From Flat Art to 3D

**In one line:** Intuition for the shape-pass then texture-pass (PBR) pipeline.

## Theory, aesthetics & inspiration

Generation separates two questions that older pipelines tangled together: what shape is this, and what is its surface made of. A first pass produces only geometry — a raw, untextured mesh resolved from the silhouette and implied volume, the way a sculptor blocks out mass before any finish. A second pass paints that fixed surface with physically based maps: base color, roughness, metallic, and normal, the channels codified by Brent Burley's 2012 Disney "principled" BRDF. Decoupling form from appearance lets each stage specialize, and mirrors studio practice — model first, look-development second. The Hunyuan3D lineage builds shape with a diffusion transformer, then synthesizes texture across the finished geometry.