Lots of new Curv activity

[Doug Moen]

Since Curv 0.5 was released on Sept 29, there has been a lot of activity.

When exporting a mesh file (STL, etc), you can choose between two mesh generators.

The original mesh generator is still the default (-Omgen=#smooth).

The new mesh generator is based on libfive (-Omgen=#sharp). It has the benefit of detecting and preserving sharp edges and corners. Shapes like cube, cylinder and cone are rendered perfectly. However, this generator introduces unacceptable artifacts into some shapes, so you will still need to use the #smooth generator for some models. Thanks to Matt Keeter for writing libfive and giving me tips on how to integrate it. See <https://github.com/curv3d/curv/blob/master/docs/Mesh_Export.rst>

Lee Fallat (@lf94 on github) has joined the development team. Lee has made numerous contributions.

• A tool for importing SVG files (github.com/curv3d/svg2curv). Work in progress. You can use this to render text in Curv.
  
• A web GUI for Curv. Live at <curv.leefallat.ca>. Work in progess. Source at <github.com/curv3d/curv-playground>.
  
• He convinced <cadhub.xyz> to integrate Curv into their product, so there is now a second Curv web GUI on the CadHub web site, different from Lee's. Also a work in progress.
  
• Created an active and lively Curv chat room, now on Matrix, at <https://app.element.io/#/room/!BbbouYwtinZcRySkDA:matrix.org>
  
• If you prefer to use Discord, the Matrix chat room is bridged to the Discord server operated by CadHub.xyz. Go to the bottom of their home page to find the Discord invite. The bridge is bidirectional, and @ references work across the bridge.

We also investigated integrating Curv with 3D printer slicers at a deeper level. The only artifact of this work is a tool to export SVX (voxel) files -- this is a standard created by Shapeways to solve some of the problems of 3D printing using mesh files. But there's very little infrastructure out there that supports SVX, so consider this another work in progress.