Non-manifold objects generated from union

[platypii]

Expected Behavior

Output a manifold STL file

Actual Behavior

The generated STL file reports errors in various 3d programs. I imported to blender to inspect the non-manifold vertices. It looks like the issue is splitting faces at different sets of edge vertices:

Steps to Reproduce the Problem

1. Generate STL from:

const { cube, cylinder } = require('@jscad/modeling').primitives
const { union } = require('@jscad/modeling').booleans

function main() {
  return union(
    cube({size: 6}),
    cylinder({radius: 10, segments: 5})
  )
}
module.exports = { main }

Specifications

• Version: 2.2.0
• Platform: Linux 62
• Environment: Node.js 14.3.0

[z3dev]

Thanks for the example.

This is a know issue. Also see #696 Things have improved but not perfect.

[z3dev]

I enjoy these kinds of issues as every application has a different take on what manifold means. Here's what MeshLab says about those 'non-manifold vertices'.