Extrude & Bevel, Inflate and Rotate built their solid from the outline by
nesting alone: a contour inside an odd number of others was a hole. Under the
nonzero rule a contour inside another that runs the same way encloses filled
art, so the effect cut a hole the object doesn't have. The fill rule now
reaches the outline builder, which leaves out contours with filled art on
both sides before pairing outlines and holes.
The public 3D and Materials panel options give Perspective as 0° to 160°
("how close or far the object appears"); it was a 0–100 % strength, for
Revolve, Extrude & Bevel, Inflate and Rotate alike.
- The eye stands where a sphere about the object's centre, √3 times its
half size (the box around it fits inside), fills that angle of the
view: 0° is none, wider brings the eye nearer, and at 160° it is just
outside the sphere, never inside the object. The documentation doesn't
say how the angle places the eye; docs/three-d.md says this is our
reading.
- `perspectiveAngle` (degrees) replaces `perspective` (%). A strength from
an earlier file or script is read as the angle that shows exactly the
same view: sin(angle / 2) = √3 × strength / 4, 100 % about 51.3°. An
angle given too wins. effect.setParams turns a stored strength into the
angle before applying new values. The parameter description names
`perspective` as the earlier form, so effect.apply and effect.setParams
still take it under the key check of #1592. Old and new code draw the four effects identically at 0, 25,
60 and 100 % (bounds equal to 1e-9).
- The dialogs' Perspective fields run 0–160°.
# Conflicts:
# docs/target-app-parity.md
The public 3D and Materials panel options list Depth, Twist, Taper and Cap
for every 3D type; Inflate had only Depth.
- Twist (0° to 360°) and Taper (1–100 %) turn and scale the back about the
shape's centre, as Extrude & Bevel's do: a puffed back is turned and
lowered in proportion, and the sides follow in slices.
- Cap: Solid closes the back; Hollow leaves it off, so the inflated front is
a shell open behind. The documentation doesn't say what Cap means for
Inflate; this reading is stated in docs/three-d.md.
- The dialog's Object tab shows them in the documented order (Depth, Twist,
Taper, Cap), then Volume and Both sides.
At 0 % volume a twisted, tapered Inflate has the extrusion's outline from
every side (tested).
A twisted, tapered, hollow Inflate draws on the canvas exactly as it
exports, and expands to faces with their own ids (tested). ROADMAP and the
parity pages list the new options; the 3D score stays at ~25 %.
A twist bends the strip between two slices into a saddle; its normal came
from one corner's triangle, which leaned so far back that from about 60° of
twist every wall was taken for facing away and dropped, leaving the front
cap alone. Each strip now takes the whole quad's average normal (Newell's),
as Inflate's facets do. A test checks the faces kept against each strip's
average normal oriented away from the axis, for twists up to 300° and four
views.
The public 3D and Materials panel options give Twist as up to 360°; it took
-360° to 360°. Values beyond either end now hold at that end (the effect is
a day old, so only fresh files carry a negative twist).
A point outside the grid can be nearer an edge further along the grid's side than one
straight ahead of it; the search stopped a ring early there. The bucket lookup is one
function.
Extrude & Bevel, Inflate and Rotate sampled every curve at sixteen points and
refused a shape past 1,024 points, about 64 curves: outlined words reached
that quickly, and Rotate refused them although it only turns the outline.
- Each curve takes as many straight pieces as keep it within 1/2000 of the
shape's size (at least 0.05 pt), by Wang's bound: 1 to 32.
- Extrude & Bevel and Inflate take up to 2,048 points, Rotate 65,536.
- Inflate's distance and crossing tests use a bucketed edge index, and
cells no edge crosses skip clipping: about 80 ms at 2,000 points (it was
over 600 ms with the old search; 95 ms at the old 1,024-point limit).
Revolve's own sampling is unchanged.
The three 3D types besides Revolve, as live effects in the three-d crate,
drawn as shaded vector faces by the canvas, SVG/PDF export and Expand
Appearance alike, from the public 3D and Materials documentation:
- Extrude & Bevel: depth (0-2000 pt), twist, taper, solid or hollow caps,
and bevels in six original cross-sections (classic, rounded, cove, step,
ogee) with width, height, repeat, spacing, inside and both sides.
- Inflate: the shape as a membrane under pressure (a Poisson solve held at
zero along the outline and holes), so it rises vertically from the edge
and rounds without creases; volume, depth and both sides. Steep cells
near the outline are refined without cracks.
- Rotate: every fill and stroke turned in 3D and shaded as one plane.
All three share Revolve's view and lighting parameters, the rotation and
light gizmos (turning about the art's centre) and a dialog with Object,
Rotation and Lighting tabs, with Position presets (Front ... Isometric
Bottom, our own values). An object takes one 3D effect. Inflate cuts the
grid cells that straddle a hole's edge with pathops, hence the new
pathops -> three-d layer order.
Docs: docs/three-d.md, mcp.md, and the 3D rows of the parity docs.
bflatastic