From 3be111af437d599fd691392a05a745b668b9de4d Mon Sep 17 00:00:00 2001
From: Stewart Allen <stewart.allen@gmail.com>
Date: Tue, 19 May 2026 19:42:55 -0400
Subject: [PATCH] add volume rendering and use that for sla by default now

---
 src/kiri/app/layers.js          | 36 +++++++++++++++++++++++
 src/kiri/mode/sla/work/slice.js | 51 ++++++++++++++++++++++++++-------
 2 files changed, 77 insertions(+), 10 deletions(-)

diff --git a/src/kiri/app/layers.js b/src/kiri/app/layers.js
index efbaf061..7111984c 100644
--- a/src/kiri/app/layers.js
+++ b/src/kiri/app/layers.js
@@ -212,6 +212,42 @@ export class Layers {
         }
     }
 
+    /**
+     * Add closed polygons as filled Z volumes.
+     * By default, the polygon Z is treated as the volume center. Pass
+     * { base:true } to treat polygon Z as the bottom face instead.
+     * @param {Polygon|Array<Polygon>} polys - Closed polygon(s), with inners preserved as voids
+     * @param {object} [options] - Options: {height, z, base, outline}
+     * @returns {Layers} This instance for chaining
+     */
+    addZVolume(polys, options) {
+        const opts = options || {};
+        const height = opts.height || 1;
+        const faces = this.current.faces;
+        polys = Array.isArray(polys) ? polys.clone(true) : [ polys.clone(true) ];
+
+        for (let poly of polys) {
+            if (poly.open || poly.length < 3) {
+                continue;
+            }
+
+            let z = opts.z !== undefined ? opts.z : poly.getZ(),
+                zoff = opts.base ? z : z - height / 2,
+                volume = poly.setZ(0).extrude(height, { zadd: zoff });
+
+            faces.appendAll(volume);
+
+            if (opts.outline) {
+                this.addPolys([
+                    poly.clone(true).setZ(zoff),
+                    poly.clone(true).setZ(zoff + height)
+                ]);
+            }
+        }
+
+        return this;
+    }
+
     /**
      * Add 2D polyline paths with width (usually FDM extrusion paths).
      * Creates flat ribbons with vertex normals for lighting.
diff --git a/src/kiri/mode/sla/work/slice.js b/src/kiri/mode/sla/work/slice.js
index 3f9b865a..76dd43fd 100644
--- a/src/kiri/mode/sla/work/slice.js
+++ b/src/kiri/mode/sla/work/slice.js
@@ -245,36 +245,67 @@ export function sla_slice(settings, widget, onupdate, ondone) {
     });
 };
 
+const SLA_RENDER_THICK = true;
+
 function doRender(widget) {
     widget.slices.forEach(slice => {
-        const render = slice.output(), lopacity = 0.6, line = 0x010101;
+        const render = slice.output(),
+            height = slice.height || 0.05,
+            lopacity = SLA_RENDER_THICK ? 1 : 0.6,
+            line = 0x010101;
 
         if (slice.unioned) {
             slice.unioned.forEach(poly => {
                 poly = poly.clone(true);//.move(widget.track.pos);
-                render
-                    .setLayer("layers", { line, face: 0x0099cc, lopacity })
-                    .addAreas([poly], { outline: true });
+                renderSlicePoly(render, "layers", poly, {
+                    line,
+                    face: 0x0099cc,
+                    lopacity,
+                    height
+                });
             });
         } else if (slice.tops) {
             slice.tops.forEach(top => {
                 let poly = top.poly;//.clone(true).move(widget.track.pos);
-                render
-                    .setLayer("layers", { line, face: 0xfcba03, lopacity })
-                    .addAreas([poly], { outline: true });
+                renderSlicePoly(render, "layers", poly, {
+                    line,
+                    face: 0xfcba03,
+                    lopacity,
+                    height
+                });
             });
         }
 
         if (slice.supports) {
             slice.supports.forEach(poly => {
-                render
-                    .setLayer("support", { line, face: 0xfcba03, lopacity })
-                    .addAreas([poly], { outline: true });
+                renderSlicePoly(render, "support", poly, {
+                    line,
+                    face: 0xfcba03,
+                    lopacity,
+                    height
+                });
             });
         }
     });
 }
 
+function renderSlicePoly(render, layer, poly, options) {
+    let { line, face, lopacity, height } = options;
+
+    render.setLayer(layer, {
+        line,
+        face,
+        lopacity,
+        opacity: SLA_RENDER_THICK ? 1 : undefined
+    });
+
+    if (SLA_RENDER_THICK) {
+        render.addZVolume([poly], { height, outline: false });
+    } else {
+        render.addAreas([poly], { outline: true });
+    }
+}
+
 function computeSupports(widget, process, progress) {
     let slices = widget.slices,
         baseIndex = widget.lastraft ? widget.lastraft.index : 0,