I got tired of FilletEdge mangling three-way corners, so I built a fillet toolkit around a different idea: on box solids, the mathematically correct fillet is closed-form — planar faces, true quarter-cylinder edges, and true sphere-octant corners (the offset-surface / Gauss-map decomposition). No corner patches, no fitting. Run What on the result and you’ll see actual spheres and cylinders, tangent-continuous at any radius up to half the shortest edge.
For everything else it runs the kernel filleter but validates the result (closed, valid, with tolerance retries) instead of handing you a silently broken polysurface, heals union seams first (MergeCoplanarFaces + edge remap — seam-split collinear edges are behind a lot of mystery failures), and previews live in the viewport with a radius slider. Erode/dilate full-body rounding and SubD chamfer-cage rounding are included as separate commands.
Rhino 8, Windows + Mac, installs via Package Manager:
https://www.food4rhino.com/en/app/tiger-fillet
Feedback and broken-fillet test files very welcome — the goal is to grow the exact engine to arbitrary planar-faced solids.
TigerFillet+.zip (10.7 KB)
