A new proposal for the “Quad remesh” tool
A major problem of the ! _QuadRemesh tool is that it shrinks the output SubD quite a lot, thus it no longer follows the intended shape and size. The reason is that it aims to snap the control points of the output SubD to the input geometry, which causes the shrinkage after the smoothing operation.
My proposal is to add an option to follow the input geometry by snapping the mid point of the SubD edges instead. However, one important exception should be made for the areas where the angle between the input faces is below a set value (default should be something like 50 degrees). That will allow replicating of shapes like water drop properly, ignoring the sharp corner at the top.
The 50-degrees angle threshold should prevent unnecessary bulging of objects that have a 45-degree chamfer (like most mechanical part designs). Of course, the user must be able to set any custom angle threshold in case that the default 50 degrees are not enough.
Test 3dm file used in this example:
NURBS to SubD Bobi.3dm (264.1 KB)
Manually optimized SubD to follow the target NURBS shape as close as possible. Note that the control polygon around the black dots 1, 2, 3 and 4 is outside the input geometry, with the middle of the control polygon being very close to the latter. The only exception is the bottom where the control polygons around black point #5 are shrunk inside, because the intent it to replicate a melted shape, thus the sharp corner of the input NURBS model is ignored.
In comparison, the current implementation of the “Interpolate SubD” option produces heavily distorted output shape, because it misses the ability to ignore sharp corners based on a user-set threshold.
“Quad remesh” with a rough polygonal preview before converting to SubD:
“Quad remesh” shrinks the SubD and can’t follow the original design intent:
The “Interpolate SubD” option produces unnecessary bulging and random distortion:
The side view of the same SubD reveals the true damage caused by the distortion:
