Turns a Topology Result into a smooth Solid (the rho2sdf method, arXiv:2512.06976): exact distances to the density iso-surface, Gaussian smoothing, then a level shift that restores the optimizer's material volume.
The Topology Optimization block to read.
Off (default): the iso level is found automatically so the surface encloses the optimizer's material volume (Σρ·Vₑ). On: Threshold sets it.
Density iso level, 0–1, used while Use threshold is on.
Saved iteration to use; 0 means the last.
Only matters with the fine grid. shape_preserving (default, a FieldCAD addition): each refined value stays within its 8 coarse neighbours, so edges round off instead of spiking outward. paper: the original method, which overshoots at creases.
On (default): loose fragments smaller than Artifact ratio are dropped.
fine (default): the smoothed field is evaluated on a grid twice as dense, for a display-quality surface. same: the optimizer's own grid, as in the original method.
Width σ of the Gaussian smoothing kernel, in grid cells (1 is the original method; wider is a FieldCAD extension). Wider removes more ripple (about 8–25 % less at 2) and the enclosed volume stays exact, but a member thinner than about σ/0.7 cells disappears, and past about 1.5 the part stops sitting flush on the design box, leaving a longer cut rim.
0 (default): plain Gaussian filtering of the exact distances. Above 0: a ridge-regularized fit instead, (A + λI)w = φ with λ = r/(1−r)·ΣK. Near 1 it smooths like one full filter pass; near 0 it reproduces every distance and keeps the grid's detail. On the cantilever test (kernel width 1.5) ripple is lowest at 1 and 26 % higher near 0, and the surface moves at most 0.61 cells across the range; no setting drops a member. The fit matches the optimizer's material volume exactly (the filter is off by about 0.8 %), but it does not compensate where the kernel is cut off at the grid edge, so it is not the default.
Extra smoothing passes of mean-curvature flow on the surface, 0–10 (0 = off; a FieldCAD addition). The enclosed volume is kept. Ripple is lowest around 10 passes and grows again beyond that, hence the cap. The surface does move: about 0.2–0.3 cells on average, up to 2–3 cells. Everything downstream (analysis, booleans, export) sees the faired shape.
Smallest fragment kept, as a share of the largest piece's size.
Values the block gives besides its output. The editor lists them under Properties, and an input can read one by reference.
The axis-aligned extent of the Solid.
The Solid's signed distance, as a field.
The Solid turned inside out: what was inside is now outside.