QuadFlow Preview — Gumroad Product Listing

Product Name

QuadFlow Preview — See the Ideal Quad Layout Before You Cut

Price

$19

Thumbnail

nostromo-deep/topology/topo-quad-flow.svg on #070809 background. "QUADFLOW" in abyss teal (#2A6B6B).

Short Description (Gumroad summary field, 160 chars)

Ghost overlay showing conformal isolines on your mesh surface. The mathematically optimal edge loops, visualized before you cut a single edge. Toggle with G.

Full Description

See the invisible geometry

Every smooth surface has an inherent quad structure hiding inside it — determined by its conformal parameterization. QuadFlow makes that structure visible.

Press G to toggle the overlay. Blue isolines appear on your mesh surface showing where the mathematically optimal edge loops would go. Where lines bunch together, curvature is high and the mesh needs more detail. Where they spread apart, the surface is flat and fewer loops are needed. The density slider controls how many isolines appear (8-20 typically). The color gradient encodes local distortion — cool blue where the chart is ideal, warm toward red where the conformal map is stretching.

What this is actually showing you

The lines aren't random. They're not a heuristic. They are the direct geometric consequence of the Cauchy-Riemann equations applied to your specific surface.

Here's the theorem: for any smooth surface with a conformal parameterization f: M → ℂ, the preimages of horizontal and vertical lines under f are orthogonal everywhere on M. That's the defining property of conformality — angles are preserved. When you draw a regular grid in UV space and map it back to 3D, the grid lines you see ARE the ideal quad edge loops. QuadFlow computes the conformal map via Boundary-First Flattening and visualizes those grid lines in the viewport at 10Hz during editing.

Use cases

Manual retopology guide: Before starting retopology on a sculpt or scan, toggle QuadFlow. The isolines show exactly where edge loops should go. Follow them, and your retopology matches the natural curvature of the surface.

Boolean cleanup planning: After a boolean operation, toggle QuadFlow on the result. The isolines reveal which regions are topologically healthy (isolines smooth and evenly spaced) and which need cleanup (isolines diverging, collapsing, or showing distortion colors).

Subdivision surface validation: Your edge flow should align with the isolines if the mesh is ready for subdivision. Mismatch means surface artifacts under displacement. Use QuadFlow to catch them before rendering.

Teaching tool: Show students the direct relationship between curvature and quad density. The isolines move as they edit, providing real-time feedback on how their modeling decisions affect the underlying geometric structure.

Kitbash part validation: Before committing a kitbash part to the main mesh, preview its QuadFlow on the target surface to verify the integration won't create isoline discontinuities.

The performance story

Conformal isoline computation was historically offline work — dozens of seconds per mesh. QuadFlow runs at 10Hz on meshes up to 10,000 vertices, interactively, during editing.

The trick is the BFF cache (bff_cache.py): the cotangent Laplacian is computed once and reused across frames unless topology changes. The Cholesky factorization is stored and reused across u/v solves. Only vertex position changes trigger recomputation, and those recompute in ~50ms on 5K verts. The overlay itself draws at 60fps because it's just line geometry.

The combined result: overlay toggle (G key) is instant, slider adjustment updates in one frame, vertex edits show updated isolines within 100ms.

Features

G key toggle: Maya-style instant overlay on/off
Density slider: 2-40 isolines per direction (default 8)
Color gradient: Blue (low distortion) → red (high distortion)
Direction filter: U-only, V-only, or both
Per-island: Works with ConformalUV's AutoIsland segmentation, or whole-mesh for open surfaces
GPU line rendering: Negligible viewport impact

Requirements

Blender 4.0+
scipy (bundled or auto-installed)
zforge-core (bundled)

Integration with other ZForge tools

QuadFlow integrates with ConformalUV (shares the same BFF cache — toggling between UV view and 3D isoline view is instant) and HolyGrail Auto-Retopo (the isolines become the actual edge loops in the extracted mesh). Owning the ZForge Suite means one BFF computation serves all three tools.

Changelog

v0.1.0 — Initial release

Conformal isoline overlay with 10Hz throttled refresh
BFF cache with hash-based topology staleness detection
Density + direction controls
GPU line rendering with distortion color gradient

File

quadflow-v0.1.0.zip (~80 KB)

QUADFLOW

What ships