💎 Geometry Painter — the pieces

Ten small pages, each one pulling a single mechanism out of the main app and looping it on its own. They exist so the moving parts can be watched instead of described: picking, resampling, culling, growth, and the four shaders that make the modes look alive. Most of them drive the production code directly.

01 · PAINTING

Surface picking & the tangent frame

One raycast becomes a point, a normal and the little basis every mode builds in. BVH on and off.

02 · PAINTING

Painting on a canvas that moves

World space versus anchor space, on two spheres that won't stop turning.

03 · PAINTING

From pointer events to a centreline

Why raw pointer samples can't space anything, and what the modes get instead.

04 · ARCHITECTURE

Generate at the maximum, cull with the slider

The real crystal mode, with a rebuild counter that never moves.

05 · ARCHITECTURE

The growth front

Birth distance, growth window and the 5% overshoot that sells the pop.

06 · SHADERS

A ribbon with no width

Every crack vertex sits on the centreline. The width is a uniform.

07 · SHADERS

Building the heat ramp

Four terms multiplied into one float, then pushed through a blackbody ramp.

08 · SHADERS

Fold-locked brightness

Share the wave phase with the fragment stage and a plane becomes fabric.

09 · SHADERS

One heartbeat, many colonies

A wave that lives in world space, so separate strokes still breathe together.

10 · LOOK

The environment is the lighting

Six emissive quads and no lights. Switch one off, lose a highlight.