v0.19.0 — Fourier optics: phase retrieval + spatial filtering

v0.19.0 — Fourier optics: phase retrieval + spatial filtering

A Fourier-optics pair built on the verified Fraunhofer FFT — one designs a Fourier-plane phase mask, the other applies one. The geometric trace is byte-identical to v0.18.0 (regression 375/375).

gerchberg_saxton — phase retrieval / CGH design

The iterative Fourier-transform algorithm: find a source-plane phase whose far-field |FFT| matches a target pattern, alternating amplitude constraints in the source and far-field planes. The far-field error is monotone non-increasing (the GS convergence guarantee), and the recovered phase mask is a computer-generated hologram for beam shaping. Canonical targets {ring, double, tophat, spot}. Validated: monotone error; a feasible target recovered to correlation 0.99; a double-spot CGH target at correlation 0.94.

spatial_filter — 4f Fourier-plane filtering (the Abbe-Porter experiment)

Coherent optical image processing: FFT an object, mask the Fourier plane, IFFT back. kind ∈ {lowpass (smooths — a square grating becomes sinusoidal), highpass (edge enhancement — removes the DC background), phase_contrast (Zernike — a quarter-turn dot on the zero order makes a pure-phase object visible in intensity)}. Validated: highpass removes the DC (mean → 0); a lowpass passing only the zero order erases the grating (uniform output); a pure-phase object (intensity std = 0) becomes visible under phase contrast (std 0.078).

Validation now 179 oracle checks. Both off-trace; the live ray-trace is byte-identical.

Install / update

Existing users on the native update channel get this as a one-click update. New install: download the zip below → Blender Preferences ▸ Add-ons ▸ Install from Disk…

Full notes: CHANGELOG.md.