feat(render): apply foot-flat in the viewer frame loop and on load

Author: a-baran-orhan

packages/posecode-render/src/index.ts

@@ -27,7 +27,7 @@ import {
   type ClipSource,
 } from "./clips.js";
 import { depenetrate } from "./depenetrate.js";
-import { alignFloorPalms } from "./contacts.js";
+import { alignFloorPalms, levelPlantedFeet } from "./contacts.js";
 
 const DEG = Math.PI / 180;
 
@@ -544,6 +544,10 @@ export function createViewer(
       // floor/landmark targets resolve against.
       applyReaches(info.reaches);
       alignFloorPalms(mannequin, info.reaches, info.pins);
+      // Plantigrade correction: keep planted soles flat to the floor so grounded
+      // lower-body poses (squat, lunge, deadlift) don't balance on the toes.
+      // Runs before the floor clamp so the leveled sole is what rests on y=0.
+      levelPlantedFeet(mannequin, info.groundLock);
       // Safety net: nothing above ever intentionally pushes part of the body
       // below the floor, so clamp the root up whenever the lowest point dips
       // below y=0, a no-op whenever the pose is legitimately grounded or
@@ -641,6 +645,7 @@ export function createViewer(
       mannequin.root.updateMatrixWorld(true);
       depenetrate(mannequin);
       groundFigureOf(mannequin);
+      levelPlantedFeet(mannequin, ir.phases[0]?.groundLock ?? []);
       captureGroundTargets();
       baseRootPos.copy(mannequin.root.position);
       baseRootQuat.copy(mannequin.root.quaternion);

packages/posecode-render/test/render.test.ts

@@ -6,6 +6,7 @@ import { solveCCD } from "../src/ik.js";
 import { poseFor } from "../src/poses.js";
 import { buildProps } from "../src/props.js";
 import { applyGroundLock, groundFigure } from "../src/groundlock.js";
+import { levelPlantedFeet } from "../src/contacts.js";
 import { parse, eulerRomFor } from "posecode-parser";
 
 const DEG = Math.PI / 180;
@@ -751,3 +752,38 @@ describe("spline interpolation (L2)", () => {
     expect(v).toBeLessThan(0.2);
   });
 });
+
+describe("foot-flat correction (L3.1)", () => {
+  it("rests a squatting foot flatter on the floor (not on the toes)", () => {
+    const src = [
+      'posecode exercise "sq"',
+      "  rig humanoid",
+      "  pose start = standing",
+      '  step "Descend" 1s settle:',
+      "    hips: flex 80",
+      "    knees: flex 95",
+      "    pelvis: hinge 25",
+      "    ground-lock: feet",
+    ].join("\n");
+    const { ir } = parse(src);
+    const tl = buildTimeline(ir!);
+    const m = buildMannequin();
+    tl.sample(1, m.bones);
+    m.root.updateMatrixWorld(true);
+    groundFigure(m);
+    applyGroundLock(m, ["feet"]);
+    const soleDot = () => {
+      const ankle = m.bones.get("ankle_left")!;
+      return new THREE.Vector3(0, -1, 0)
+        .applyQuaternion(ankle.getWorldQuaternion(new THREE.Quaternion()))
+        .normalize()
+        .dot(new THREE.Vector3(0, -1, 0));
+    };
+    const before = soleDot();
+    levelPlantedFeet(m, ["feet"]);
+    m.root.updateMatrixWorld(true);
+    // Leveling makes the sole markedly flatter than raw ground-lock leaves it.
+    expect(soleDot()).toBeGreaterThan(before);
+    expect(soleDot()).toBeGreaterThan(0.9);
+  });
+});