InsertPrim — Gumroad Product Listing

Product Name

InsertPrim — One-Click Primitive Fusion for Blender

Price

$19 (Early Access) → $29 (Standard)

Thumbnail

nostromo-deep/mesh_ops/mesh-qmesh.svg on #070809 background. "INSERTPRIM" in smolder red (#8B3A3A).

Short Description (Gumroad summary field, 160 chars)

Select face → insert cylinder/cube/sphere → auto-fuse with clean topology. No manual boolean cleanup. Biarc seam resolution ships zero triangles at the boundary.

Full Description

The problem

Every hard-surface modeler knows this sequence: inset face, extrude, boolean, cleanup topology, merge verts, fix triangles, fix n-gons. Eight to twelve operations to insert one cylinder into a flat panel. And when the boundary vertex count doesn't match (12 cylinder segments meeting a 16-vert hole), standard "merge by distance" creates triangles at every mismatch.

That's the topology tax. Every modeler pays it, every day.

The solution

Select a face. Pick a primitive. Click. Done.

InsertPrim does the full pipeline in one operation:

Extracts face normal via numpy cross product
Generates the primitive, rotated to match the face orientation (Rodrigues formula — exact, no gimbal)
Finds the intersection boundary between the primitive and the host mesh
Removes interior faces that fall inside the primitive's projection
The critical innovation: resamples both boundaries to a common vertex count using biarc curve fitting, then pairs 1:1. Zero triangles at the seam.
Welds matched vertex pairs using the Hungarian optimal assignment
Validates the result through the composite safety gate (topology + conformal)
Cleans up any remaining tris/n-gons via quad flow optimization
Records the operation in construction history (undo + AI pattern learning)

What makes this different

No other tool does arc-length biarc resampling for seam resolution. Everyone else merges by distance and accepts the triangles. InsertPrim is the first tool that produces quad-clean results regardless of vertex count mismatch.

No other tool runs a composite safety gate before committing. Every InsertPrim operation is verified against four topology checks and a conformal distortion threshold. If it would create a non-manifold edge or a curvature spike, it refuses the operation and tells you why.

No other tool records construction history at this granularity. Every operation captures: selected face, primitive type, parameters (radius/depth/segments), affected vertices, quality score before and after. Undo is exact. AI pattern learning sees "this modeler uses 12-segment cylinders at 0.5 radius on flat panels" and suggests it as the default next time.

Features

Primitives: Cylinder, Cube, Sphere, Cone, Tube (hollow cylinder)
Auto-alignment: Rodrigues rotation — exact alignment to any face normal
Biarc seam resolution: 1:1 vertex pairing regardless of count mismatch
Composite safety gate: Validates every operation before commit
Construction history: Full undo + parameter recording
Custom presets: Save your favorite primitive configurations
Keyboard shortcut: Ctrl+Shift+I (configurable)
N-panel: Parameters, presets, last-operation readout

Under the hood

Built on zforge-core — the open-source geometry intelligence library behind all ZForge products. Pure NumPy (no CUDA, no compiled extensions, no external binaries). The math is the same math used in academic geometry processing research: Boundary-First Flattening for conformal verification, Hungarian algorithm for optimal assignment, biarc chain fitting for G1-continuous resampling.

Workflow example


Standard Blender (8 operations, ~90 seconds):
  1. Select face → Inset (I key)
  2. Adjust inset size
  3. Extrude (E key)
  4. Adjust extrusion
  5. Select intersecting faces
  6. Delete
  7. Merge by distance
  8. Fix triangles manually

With InsertPrim (1 operation, ~3 seconds):
  1. Select face → Ctrl+Shift+I → Cylinder → Done

Requirements

Blender 4.0+
Python 3.10+ (ships with Blender)
scipy (auto-installed on first use, or install manually with the bundled installer)
zforge-core (bundled)

Installation

Download insertprim-v0.1.0.zip
Blender → Edit → Preferences → Add-ons → Install from File
Select the zip, enable the addon
3D Viewport → Press N → InsertPrim tab appears

Or use the automated installer: python install_zforge.py --products insertprim

Changelog

v0.1.0 — Initial release

5 primitive types with parametric controls
Biarc seam resolution (the headline feature)
Composite safety gate integration
Construction history recording
BB5 Maya-style integration

File

insertprim-v0.1.0.zip (~60 KB, Blender addon)

Call-to-action

Get InsertPrim — the tool every hard-surface modeler needs daily.

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Part of the ZForge ecosystem:

TopoGuard (free) — Real-time topology safety
SpectralMesh (free) — Objective mesh quality scoring
ConformalUV ($29) — Conformal UV unwrapping with UDIM
QuadFlow ($19) — Retopology guide overlay
KitBash Snap ($29) — Drag-and-fuse assembly
HolyGrail ($149) — Automated quad retopology
ZForge Suite ($99) — Bundle of all 10 tools

INSERTPRIM

What ships