Preferences > Graphics > Viewport gets a Field of view row under Perspective view: the UI kit's
slider in degrees, 15 to 90, dragged or typed and kept to whole degrees, enabled only while
Perspective view is on. The preference is perspective_fov, in radians (default 0.6, about 34°,
so the default view draws exactly as before), and Restore Defaults puts it back.
One place decides the angle the view is drawn with: SolveApp::view_fov(), the preference with
Perspective view on and 0 with it off or while a sketch is open. A saved value outside 15°-90°
reads as the default. projection and fit_bounds read it (fit_bounds' second hard-coded copy of
the 0.6, tan(0.3), now goes through Camera::half_height), and so does the headless fit.
perspective_view() stays, as view_fov() > 0, so #4291 needs no change.
When the angle changes from one perspective angle to another, the camera's distance scales by
tan(old/2) / tan(new/2), with a running view animation's ends, so the target keeps its size and
the slider changes the depth, not the zoom. prefs::follow_view_fov does it once per frame and
after ui.prefs, Cancel and Restore Defaults; a parallel view keeps the last perspective angle,
and while Render is open the camera is Render's own, so the change waits for the design view.
The Render workspace's Perspective check box turns perspective on at the preference's angle,
not π/4; a saved render setup keeps its own. ui.prefs takes perspective_fov and refuses values
outside the range; ui.camera reports the angle the window draws with, and checks a replayed
camera against it, so its reply still replays. Field of view is in en, ar, de, he, ja, ko, vi and zh;
the ui.prefs settings list in docs/control-protocol.md and the guide's tour describe it.
Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>
CamWight
a985b8ee17