diff --git a/ROADMAP.md b/ROADMAP.md
index f5daa2d3..0dcba203 100644
--- a/ROADMAP.md
+++ b/ROADMAP.md
@@ -131,6 +131,7 @@ app's JSON control channel (`deckcraft --control PORT`).
| Date | What landed |
|---|---|
+| 2026-10-21 | 3-D contours, extrusion depths and bevels keep their size in points inside a group whose child coordinates scale its shapes: a 1 pt contour on a small extruded cube in a legacy group drew hundreds of points wide, a band across the slide |
| 2026-10-18 | Native chart sidecar bytes move from JSON arrays into referenced ZIP entries, with shared media byte/item limits and bounded reads; older inline sidecars still load. Synthetic format regressions cover large workbooks and malformed members |
| 2026-10-17 | Opening a file caps absurd effect sizes (glow, soft edges, shadows, reflections, on shapes, text and table text) at what Format Shape allows: a glow of 10^18 pt in a .pptx made rendering ask for 34 GB and abort |
| 2026-10-17 | Opening a .deckcraft file whose shapes repeat an id gives the repeats fresh ids (groups, layouts and masters too), so the deck validates and edits by id find one shape |
@@ -245,6 +246,7 @@ app's JSON control channel (`deckcraft --control PORT`).
| 2026-10-15 | trivial | Progress log: PPTX trigger click-step round trip. Feature scores and milestone names unchanged |
| 2026-10-16 | trivial | Progress log: PNG export with a transparent background (#784) |
| 2026-10-16 | trivial | Progress log: a `.ppsx` from the system starts the slide show (#862) |
+| 2026-10-21 | trivial | Progress log: 3-D sizes in scaled groups stay in points |
| 2026-10-14 | trivial | remote MCP checks reply IDs, envelopes and bounded newline framing (#718) |
| 2026-10-14 | minor | Gray list markers on empty paragraphs while editing; caret keeps the list indent before typing |
| 2026-10-14 | minor | Community PR wave folded: headline breadth 84% over 191 features (P0 92%, P1 82%, P2 55%) and the feature-area breadths from `cargo xtask parity`; one row per area; Upcoming item 2 merged; per-PR count notes dropped from the progress log. Ready stays ~55%, stage alpha |
diff --git a/crates/render/src/lib.rs b/crates/render/src/lib.rs
index cf124a9f..f88d492a 100644
--- a/crates/render/src/lib.rs
+++ b/crates/render/src/lib.rs
@@ -833,6 +833,15 @@ impl Renderer {
if depth > 0 && view.determinant().abs() > 1e-12 && view.is_finite() { (view, view.inverse() * m) } else { (m, Affine::IDENTITY) }
}
+ /// Shape-space units per point: a group's child coordinates can scale a shape's box (a legacy
+ /// 1360-unit child space makes one unit hundreds of EMUs), but 3-D sizes kept in points
+ /// (contour width, extrusion depth, bevel) stay points, as PowerPoint draws them. 1 outside a
+ /// group.
+ fn per_point(&self, m: Affine, depth: usize) -> f64 {
+ let k = scale_of(self.line_space(m, depth).1);
+ if k.is_finite() && k > 1e-12 { 1.0 / k } else { 1.0 }
+ }
+
/// The size and transform a shape's text is set in: inside a group whose child coordinates
/// scale the shape, the shape's size in slide points and `m` with that scale taken out, so
/// insets and font sizes stay in points; otherwise `w`, `h` and `m` themselves.
@@ -1060,7 +1069,8 @@ impl Renderer {
};
let pre = m * turn.inverse();
let lit = light::Lighting::from_raw(raw);
- extrude::draw(ctx, &outline, w, h, &cam, ex.depth, pre, turn, extrude::side_color(rctx, &ex, face), &lit);
+ let d = ex.depth * self.per_point(m, depth);
+ extrude::draw(ctx, &outline, w, h, &cam, d, pre, turn, extrude::side_color(rctx, &ex, face), &lit);
}
// A 3-D contour: a band around the outline, behind the face (and in front of any sides).
if let Some(raw) = effects.as_ref().and_then(|e| e.raw3d.as_deref())
@@ -1071,7 +1081,7 @@ impl Renderer {
_ => None,
};
let col = c.color.as_ref().map(|k| rctx.color(k, face)).or(face).unwrap_or(Rgba::rgb(0xff, 0xff, 0xff));
- extrude::draw_contour(ctx, &outline, m, c.width, col, &light::Lighting::from_raw(raw));
+ extrude::draw_contour(ctx, &outline, m, c.width * self.per_point(m, depth), col, &light::Lighting::from_raw(raw));
}
// Fill.
match &s.kind {
@@ -1166,6 +1176,8 @@ impl Renderer {
};
// A 3-D bevel: the face and a band inside the outline lit as surfaces.
if let Some(bv) = effects.as_ref().and_then(|e| e.raw3d.as_deref()).and_then(bevel::from_raw) {
+ let k = self.per_point(m, depth);
+ let bv = bevel::Bevel { w: bv.w * k, h: bv.h * k, ..bv };
let solid = match &fill {
Some(Fill::Solid { color: c }) => Some(rctx.color(c, fill_ph)),
_ => None,
diff --git a/crates/render/src/tests.rs b/crates/render/src/tests.rs
index 4ee1c889..d7122f05 100644
--- a/crates/render/src/tests.rs
+++ b/crates/render/src/tests.rs
@@ -2265,6 +2265,51 @@ fn extrusions_show_their_sides_under_a_turned_camera() {
assert_eq!(ink(&flat, 0, 960), 0);
}
+#[test]
+fn group_child_scale_does_not_scale_3d_depth_contours_or_bevels() {
+ // A legacy group child space (here 100 points per unit) scales the shapes' boxes, but
+ // extrusion depths, contour widths and bevels are points: a 1 pt contour on a small extruded
+ // cube in such a group was drawn hundreds of points wide, a band across the whole slide.
+ let mut deck = extruded_deck();
+ let bevelled = Shape {
+ id: ShapeId(704),
+ xfrm: Some(Xfrm::new(40.0, 340.0, 170.0, 130.0)),
+ geom: Geom::preset("rect"),
+ style: Some(ShapeStyle::accent(deckcraft_color::SchemeSlot::Accent1)),
+ effects: Some(deckcraft_model::Effects {
+ raw3d: Some(r#""#.into()),
+ ..Default::default()
+ }),
+ ..Default::default()
+ };
+ std::sync::Arc::make_mut(&mut deck.slides[0]).shapes.push(bevelled);
+ let shapes = deck.slides[0].shapes.clone();
+ let grouped = |k: f64| {
+ let children = shapes
+ .iter()
+ .map(|s| {
+ let x = s.xfrm.unwrap_or_default();
+ Shape { xfrm: Some(Xfrm::new(x.x / k, x.y / k, x.w / k, x.h / k)), ..s.clone() }
+ })
+ .collect();
+ let group = Shape {
+ id: ShapeId(10),
+ xfrm: Some(Xfrm::new(0.0, 0.0, 960.0, 540.0)),
+ kind: ShapeKind::Group { children, child: Xfrm::new(0.0, 0.0, 960.0 / k, 540.0 / k) },
+ ..Default::default()
+ };
+ render_slide(&deck_with(vec![group]), 0, &RenderOpts { scale: 1.0, ..Default::default() })
+ };
+ let reference = grouped(1.0);
+ let ink = |img: &Image| img.pixels.as_chunks::<4>().0.iter().filter(|p| **p != [255, 255, 255, 255]).count();
+ let drawn = ink(&reference);
+ assert!(drawn > 20_000, "the reference draws the shapes: {drawn}");
+ let scaled = grouped(100.0);
+ let (n, d) = (ink(&scaled), differing(&reference, &scaled));
+ assert!(n.abs_diff(drawn) * 20 < drawn, "{n} inked pixels against {drawn}");
+ assert!(d * 20 < drawn, "{d} differing values against {drawn} inked pixels");
+}
+
#[test]
fn table_rows_below_the_slide_are_not_laid_out_and_the_slide_looks_the_same() {
// A fuzzed deck's 200 x 200 table of long text took 70 s to draw, most of it off the slide.