From cd259c2db38115c7db92947de7e318fc0ee157ae Mon Sep 17 00:00:00 2001
From: Ryoichi Ando <ryich.ando@gmail.com>
Date: Fri, 27 Dec 2024 10:54:06 +0900
Subject: [PATCH] cone mesh creation improved

---
 .github/workflows/example_cards.yml           | 15 ++++
 .github/workflows/example_curtain.yml         | 15 ++++
 .github/workflows/example_drape.yml           | 15 ++++
 .github/workflows/example_friction.yml        | 15 ++++
 .github/workflows/example_hang.yml            | 15 ++++
 .github/workflows/example_needle.yml          | 15 ++++
 .github/workflows/example_stack.yml           | 15 ++++
 .github/workflows/example_trampoline.yml      | 15 ++++
 .github/workflows/example_trapped.yml         | 15 ++++
 .../workflows/template/example_template.yml   | 15 ++++
 examples/cards.ipynb                          |  2 +-
 examples/curtain.ipynb                        |  2 +-
 examples/drape.ipynb                          |  4 +-
 examples/friction.ipynb                       |  2 +-
 examples/frontend/_mesh_.py                   | 81 ++++++++++++++++++-
 examples/frontend/_scene_.py                  | 11 ++-
 examples/hang.ipynb                           |  5 +-
 examples/headless.py                          |  2 +-
 examples/needle.ipynb                         | 12 +--
 examples/stack.ipynb                          |  2 +-
 examples/trampoline.ipynb                     |  4 +-
 examples/trapped.ipynb                        |  2 +-
 22 files changed, 258 insertions(+), 21 deletions(-)

diff --git a/.github/workflows/example_cards.yml b/.github/workflows/example_cards.yml
index 765fe2a..043a8bd 100644
--- a/.github/workflows/example_cards.yml
+++ b/.github/workflows/example_cards.yml
@@ -48,6 +48,21 @@ jobs:
       - name: 5th run
         run: bash $HELPER_PATH run ${EXAMPLE_NAME}.py
 
+      - name: 6th run
+        run: bash $HELPER_PATH run ${EXAMPLE_NAME}.py
+
+      - name: 7th run
+        run: bash $HELPER_PATH run ${EXAMPLE_NAME}.py
+
+      - name: 8th run
+        run: bash $HELPER_PATH run ${EXAMPLE_NAME}.py
+
+      - name: 9th run
+        run: bash $HELPER_PATH run ${EXAMPLE_NAME}.py
+
+      - name: 10th run
+        run: bash $HELPER_PATH run ${EXAMPLE_NAME}.py
+
       - name: shutdown
         if: always()
         run: bash $HELPER_PATH delete
diff --git a/.github/workflows/example_curtain.yml b/.github/workflows/example_curtain.yml
index 0def0b6..219a249 100644
--- a/.github/workflows/example_curtain.yml
+++ b/.github/workflows/example_curtain.yml
@@ -48,6 +48,21 @@ jobs:
       - name: 5th run
         run: bash $HELPER_PATH run ${EXAMPLE_NAME}.py
 
+      - name: 6th run
+        run: bash $HELPER_PATH run ${EXAMPLE_NAME}.py
+
+      - name: 7th run
+        run: bash $HELPER_PATH run ${EXAMPLE_NAME}.py
+
+      - name: 8th run
+        run: bash $HELPER_PATH run ${EXAMPLE_NAME}.py
+
+      - name: 9th run
+        run: bash $HELPER_PATH run ${EXAMPLE_NAME}.py
+
+      - name: 10th run
+        run: bash $HELPER_PATH run ${EXAMPLE_NAME}.py
+
       - name: shutdown
         if: always()
         run: bash $HELPER_PATH delete
diff --git a/.github/workflows/example_drape.yml b/.github/workflows/example_drape.yml
index 92f88ff..fbf0fff 100644
--- a/.github/workflows/example_drape.yml
+++ b/.github/workflows/example_drape.yml
@@ -48,6 +48,21 @@ jobs:
       - name: 5th run
         run: bash $HELPER_PATH run ${EXAMPLE_NAME}.py
 
+      - name: 6th run
+        run: bash $HELPER_PATH run ${EXAMPLE_NAME}.py
+
+      - name: 7th run
+        run: bash $HELPER_PATH run ${EXAMPLE_NAME}.py
+
+      - name: 8th run
+        run: bash $HELPER_PATH run ${EXAMPLE_NAME}.py
+
+      - name: 9th run
+        run: bash $HELPER_PATH run ${EXAMPLE_NAME}.py
+
+      - name: 10th run
+        run: bash $HELPER_PATH run ${EXAMPLE_NAME}.py
+
       - name: shutdown
         if: always()
         run: bash $HELPER_PATH delete
diff --git a/.github/workflows/example_friction.yml b/.github/workflows/example_friction.yml
index f80eed0..6ca870c 100644
--- a/.github/workflows/example_friction.yml
+++ b/.github/workflows/example_friction.yml
@@ -48,6 +48,21 @@ jobs:
       - name: 5th run
         run: bash $HELPER_PATH run ${EXAMPLE_NAME}.py
 
+      - name: 6th run
+        run: bash $HELPER_PATH run ${EXAMPLE_NAME}.py
+
+      - name: 7th run
+        run: bash $HELPER_PATH run ${EXAMPLE_NAME}.py
+
+      - name: 8th run
+        run: bash $HELPER_PATH run ${EXAMPLE_NAME}.py
+
+      - name: 9th run
+        run: bash $HELPER_PATH run ${EXAMPLE_NAME}.py
+
+      - name: 10th run
+        run: bash $HELPER_PATH run ${EXAMPLE_NAME}.py
+
       - name: shutdown
         if: always()
         run: bash $HELPER_PATH delete
diff --git a/.github/workflows/example_hang.yml b/.github/workflows/example_hang.yml
index 626d1d2..391a27f 100644
--- a/.github/workflows/example_hang.yml
+++ b/.github/workflows/example_hang.yml
@@ -48,6 +48,21 @@ jobs:
       - name: 5th run
         run: bash $HELPER_PATH run ${EXAMPLE_NAME}.py
 
+      - name: 6th run
+        run: bash $HELPER_PATH run ${EXAMPLE_NAME}.py
+
+      - name: 7th run
+        run: bash $HELPER_PATH run ${EXAMPLE_NAME}.py
+
+      - name: 8th run
+        run: bash $HELPER_PATH run ${EXAMPLE_NAME}.py
+
+      - name: 9th run
+        run: bash $HELPER_PATH run ${EXAMPLE_NAME}.py
+
+      - name: 10th run
+        run: bash $HELPER_PATH run ${EXAMPLE_NAME}.py
+
       - name: shutdown
         if: always()
         run: bash $HELPER_PATH delete
diff --git a/.github/workflows/example_needle.yml b/.github/workflows/example_needle.yml
index bc83936..94e1661 100644
--- a/.github/workflows/example_needle.yml
+++ b/.github/workflows/example_needle.yml
@@ -48,6 +48,21 @@ jobs:
       - name: 5th run
         run: bash $HELPER_PATH run ${EXAMPLE_NAME}.py
 
+      - name: 6th run
+        run: bash $HELPER_PATH run ${EXAMPLE_NAME}.py
+
+      - name: 7th run
+        run: bash $HELPER_PATH run ${EXAMPLE_NAME}.py
+
+      - name: 8th run
+        run: bash $HELPER_PATH run ${EXAMPLE_NAME}.py
+
+      - name: 9th run
+        run: bash $HELPER_PATH run ${EXAMPLE_NAME}.py
+
+      - name: 10th run
+        run: bash $HELPER_PATH run ${EXAMPLE_NAME}.py
+
       - name: shutdown
         if: always()
         run: bash $HELPER_PATH delete
diff --git a/.github/workflows/example_stack.yml b/.github/workflows/example_stack.yml
index 2431a18..e747896 100644
--- a/.github/workflows/example_stack.yml
+++ b/.github/workflows/example_stack.yml
@@ -48,6 +48,21 @@ jobs:
       - name: 5th run
         run: bash $HELPER_PATH run ${EXAMPLE_NAME}.py
 
+      - name: 6th run
+        run: bash $HELPER_PATH run ${EXAMPLE_NAME}.py
+
+      - name: 7th run
+        run: bash $HELPER_PATH run ${EXAMPLE_NAME}.py
+
+      - name: 8th run
+        run: bash $HELPER_PATH run ${EXAMPLE_NAME}.py
+
+      - name: 9th run
+        run: bash $HELPER_PATH run ${EXAMPLE_NAME}.py
+
+      - name: 10th run
+        run: bash $HELPER_PATH run ${EXAMPLE_NAME}.py
+
       - name: shutdown
         if: always()
         run: bash $HELPER_PATH delete
diff --git a/.github/workflows/example_trampoline.yml b/.github/workflows/example_trampoline.yml
index 069ffcf..3e8cca0 100644
--- a/.github/workflows/example_trampoline.yml
+++ b/.github/workflows/example_trampoline.yml
@@ -48,6 +48,21 @@ jobs:
       - name: 5th run
         run: bash $HELPER_PATH run ${EXAMPLE_NAME}.py
 
+      - name: 6th run
+        run: bash $HELPER_PATH run ${EXAMPLE_NAME}.py
+
+      - name: 7th run
+        run: bash $HELPER_PATH run ${EXAMPLE_NAME}.py
+
+      - name: 8th run
+        run: bash $HELPER_PATH run ${EXAMPLE_NAME}.py
+
+      - name: 9th run
+        run: bash $HELPER_PATH run ${EXAMPLE_NAME}.py
+
+      - name: 10th run
+        run: bash $HELPER_PATH run ${EXAMPLE_NAME}.py
+
       - name: shutdown
         if: always()
         run: bash $HELPER_PATH delete
diff --git a/.github/workflows/example_trapped.yml b/.github/workflows/example_trapped.yml
index 0a059d3..23f81ae 100644
--- a/.github/workflows/example_trapped.yml
+++ b/.github/workflows/example_trapped.yml
@@ -48,6 +48,21 @@ jobs:
       - name: 5th run
         run: bash $HELPER_PATH run ${EXAMPLE_NAME}.py
 
+      - name: 6th run
+        run: bash $HELPER_PATH run ${EXAMPLE_NAME}.py
+
+      - name: 7th run
+        run: bash $HELPER_PATH run ${EXAMPLE_NAME}.py
+
+      - name: 8th run
+        run: bash $HELPER_PATH run ${EXAMPLE_NAME}.py
+
+      - name: 9th run
+        run: bash $HELPER_PATH run ${EXAMPLE_NAME}.py
+
+      - name: 10th run
+        run: bash $HELPER_PATH run ${EXAMPLE_NAME}.py
+
       - name: shutdown
         if: always()
         run: bash $HELPER_PATH delete
diff --git a/.github/workflows/template/example_template.yml b/.github/workflows/template/example_template.yml
index e9e0c56..6633183 100644
--- a/.github/workflows/template/example_template.yml
+++ b/.github/workflows/template/example_template.yml
@@ -48,6 +48,21 @@ jobs:
       - name: 5th run
         run: bash $HELPER_PATH run ${EXAMPLE_NAME}.py
 
+      - name: 6th run
+        run: bash $HELPER_PATH run ${EXAMPLE_NAME}.py
+
+      - name: 7th run
+        run: bash $HELPER_PATH run ${EXAMPLE_NAME}.py
+
+      - name: 8th run
+        run: bash $HELPER_PATH run ${EXAMPLE_NAME}.py
+
+      - name: 9th run
+        run: bash $HELPER_PATH run ${EXAMPLE_NAME}.py
+
+      - name: 10th run
+        run: bash $HELPER_PATH run ${EXAMPLE_NAME}.py
+
       - name: shutdown
         if: always()
         run: bash $HELPER_PATH delete
diff --git a/examples/cards.ipynb b/examples/cards.ipynb
index 9df3289..21e9363 100644
--- a/examples/cards.ipynb
+++ b/examples/cards.ipynb
@@ -47,7 +47,7 @@
     "for i in reversed(range(n_stack)):\n",
     "    _x, _y = make_row(i+1, _x, _y)\n",
     "\n",
-    "scene.add(\"sphere\").at(-2,1,0).velocity(2.3,0,0)\n",
+    "scene.add(\"sphere\").at(-2,1,0).jitter().velocity(2.3,0,0)\n",
     "scene.add_invisible_wall([0,0,0],[0,1,0])\n",
     "\n",
     "fixed = scene.build().report()\n",
diff --git a/examples/curtain.ipynb b/examples/curtain.ipynb
index cb40c44..b5deaea 100644
--- a/examples/curtain.ipynb
+++ b/examples/curtain.ipynb
@@ -26,7 +26,7 @@
     "    obj.direction([0,1,0],[0,0,1])\n",
     "    obj.pin(obj.grab([0, 1, 0]))\n",
     "\n",
-    "scene.add(\"sphere\").at(-1, 0, 0).pin().move_by([8,0,0],5)\n",
+    "scene.add(\"sphere\").at(-1, 0, 0).jitter().pin().move_by([8,0,0],5)\n",
     "\n",
     "fixed = scene.build().report()\n",
     "fixed.preview();"
diff --git a/examples/drape.ipynb b/examples/drape.ipynb
index dc8a407..5a45fd2 100644
--- a/examples/drape.ipynb
+++ b/examples/drape.ipynb
@@ -45,8 +45,8 @@
     "    # set fiber directions required for Baraff-Witkin\n",
     "    obj.direction([1, 0, 0], [0, 0, 1])\n",
     "\n",
-    "# add a sphere mesh at a lower position and set it static collider\n",
-    "scene.add(\"sphere\").at(0, -0.5 - gap, 0).pin()\n",
+    "# add a sphere mesh at a lower position with jitter and set it static collider\n",
+    "scene.add(\"sphere\").at(0, -0.5 - gap, 0).jitter().pin()\n",
     "\n",
     "# compile the scene and report stats\n",
     "fixed = scene.build().report()\n",
diff --git a/examples/friction.ipynb b/examples/friction.ipynb
index 5d7c857..10a7b30 100644
--- a/examples/friction.ipynb
+++ b/examples/friction.ipynb
@@ -20,7 +20,7 @@
     "\n",
     "scene = app.scene.create(\"friction\")\n",
     "armadillo = scene.add(\"armadillo\")\n",
-    "armadillo.rotate(180,\"y\").rotate(-90,\"x\").rotate(-30,\"z\").at(-5,3,-0.25)\n",
+    "armadillo.rotate(180,\"y\").rotate(-90,\"x\").rotate(-30,\"z\").at(-5,3,-0.25).jitter()\n",
     "\n",
     "deg = 180*np.arctan(0.5)/np.pi\n",
     "scene.add(\"slope\").rotate(-deg,\"z\").pin()\n",
diff --git a/examples/frontend/_mesh_.py b/examples/frontend/_mesh_.py
index 2f1aaaa..9ac8cf2 100644
--- a/examples/frontend/_mesh_.py
+++ b/examples/frontend/_mesh_.py
@@ -103,10 +103,85 @@ def cylinder(self, r: float = 1, height: float = 2, n: int = 32) -> "TriMesh":
 
         return self._from_o3d(o3d.geometry.TriangleMesh.create_cylinder(r, height, n))
 
-    def cone(self, r: float = 1, height: float = 2, n: int = 32) -> "TriMesh":
-        import open3d as o3d
+    def cone(
+        self,
+        Nr: int = 16,
+        Ny: int = 16,
+        Nb: int = 4,
+        radius: float = 0.5,
+        height: float = 2,
+    ) -> "TriMesh":
+        V = [[0, 0, height], [0, 0, 0]]
+        T = []
+        ind_btm_center = 0
+        ind_tip = 1
+        offset = []
+        offset_btm = len(V)
+
+        for k in reversed(range(Ny)):
+            if k > 0:
+                r = k / (Ny - 1)
+                r = r * r
+                offset.append(len(V))
+                for i in range(Nr):
+                    t = 2 * np.pi * i / Nr
+                    x, y = radius * r * np.cos(t), radius * r * np.sin(t)
+                    V.append([x, y, height * r])
+
+        for j in offset[0:-1]:
+            for i in range(Nr):
+                ind00, ind10 = i, (i + 1) % Nr
+                ind01, ind11 = ind00 + Nr, ind10 + Nr
+                if i % 2 == 0:
+                    T.append([ind00 + j, ind01 + j, ind10 + j])
+                    T.append([ind10 + j, ind01 + j, ind11 + j])
+                else:
+                    T.append([ind00 + j, ind11 + j, ind10 + j])
+                    T.append([ind00 + j, ind01 + j, ind11 + j])
+
+        j = offset[-1]
+        for i in range(Nr):
+            ind0, ind1 = i, (i + 1) % Nr
+            T.append([ind0 + j, ind_tip, ind1 + j])
+
+        offset = []
+        for k in reversed(range(Nb)):
+            if k > 0:
+                r = k / Nb
+                offset.append(len(V))
+                for i in range(Nr):
+                    t = 2 * np.pi * i / Nr
+                    x, y = radius * r * np.cos(t), radius * r * np.sin(t)
+                    V.append([x, y, height])
+
+        for j in offset[0:-1]:
+            for i in range(Nr):
+                ind00, ind10 = i, (i + 1) % Nr
+                ind01, ind11 = ind00 + Nr, ind10 + Nr
+                if i % 2 == 0:
+                    T.append([ind00 + j, ind10 + j, ind01 + j])
+                    T.append([ind10 + j, ind11 + j, ind01 + j])
+                else:
+                    T.append([ind00 + j, ind10 + j, ind11 + j])
+                    T.append([ind00 + j, ind11 + j, ind01 + j])
+
+        j = offset[-1]
+        for i in range(Nr):
+            ind0, ind1 = i, (i + 1) % Nr
+            T.append([ind0 + j, ind1 + j, ind_btm_center])
+
+        j0, j1 = offset_btm, offset[0]
+        for i in range(Nr):
+            ind00, ind10 = i + j0, (i + 1) % Nr + j0
+            ind01, ind11 = i + j1, (i + 1) % Nr + j1
+            if i % 2 == 0:
+                T.append([ind00, ind10, ind01])
+                T.append([ind10, ind11, ind01])
+            else:
+                T.append([ind00, ind10, ind11])
+                T.append([ind00, ind11, ind01])
 
-        return self._from_o3d(o3d.geometry.TriangleMesh.create_cone(r, height, n))
+        return TriMesh.create(np.array(V), np.array(T), self._cache_dir)
 
     def torus(self, r: float = 1, R: float = 0.25, n: int = 32) -> "TriMesh":
         import open3d as o3d
diff --git a/examples/frontend/_scene_.py b/examples/frontend/_scene_.py
index 8742646..da90425 100644
--- a/examples/frontend/_scene_.py
+++ b/examples/frontend/_scene_.py
@@ -794,7 +794,7 @@ def __init__(self, asset: AssetManager, name: str):
 
     def clear(self):
         self._param = {}
-        self._at = [0, 0, 0]
+        self._at = [0.0, 0.0, 0.0]
         self._scale = 1.0
         self._rotation = np.eye(3)
         self._color = []
@@ -896,6 +896,15 @@ def at(self, x: float, y: float, z: float) -> "Object":
         self._at = [x, y, z]
         return self
 
+    def jitter(self, r: float = 1e-2) -> "Object":
+        dx = np.random.random()
+        dy = np.random.random()
+        dz = np.random.random()
+        self._at[0] += r * dx
+        self._at[1] += r * dy
+        self._at[2] += r * dz
+        return self
+
     def atop(self, object: "Object", margin: float = 0.0) -> "Object":
         a_bbox, a_center = self.bbox()
         b_bbox, b_center = object.bbox()
diff --git a/examples/hang.ipynb b/examples/hang.ipynb
index 5dc8325..75261f5 100644
--- a/examples/hang.ipynb
+++ b/examples/hang.ipynb
@@ -30,10 +30,13 @@
    "metadata": {},
    "outputs": [],
    "source": [
+    "import random\n",
+    "jitter_time = 0.1 + 0.5 * random.random()\n",
+    "\n",
     "param = app.session.param().set(\"dt\",0.001)\n",
     "param.set(\"strain-limit-eps\", 0.005).set(\"strain-limit-tau\", 0.005)\n",
     "param.set(\"frames\",200)\n",
-    "param.dyn(\"gravity\").time(1).hold().time(1.1).change(9.8).time(2.0).change(-9.8);"
+    "param.dyn(\"gravity\").time(1).hold().time(1+jitter_time).change(9.8).time(2.0).change(-9.8);"
    ]
   },
   {
diff --git a/examples/headless.py b/examples/headless.py
index 4b66e89..4f21477 100644
--- a/examples/headless.py
+++ b/examples/headless.py
@@ -17,7 +17,7 @@
     obj.direction([0, 1, 0], [0, 0, 1])
     obj.pin(obj.grab([0, 1, 0]))
 
-scene.add("sphere").at(-1, 0, 0).pin().move_by([8, 0, 0], 5)
+scene.add("sphere").at(-1, 0, 0).jitter().pin().move_by([8, 0, 0], 5)
 fixed = scene.build()
 
 param = app.session.param()
diff --git a/examples/needle.ipynb b/examples/needle.ipynb
index 06420a7..d8622ba 100644
--- a/examples/needle.ipynb
+++ b/examples/needle.ipynb
@@ -14,22 +14,22 @@
     "V, F = app.mesh.square(res=129)\n",
     "app.asset.add.tri(\"sheet\", V, F)\n",
     "\n",
-    "V, F = app.mesh.cone(height=5,n=5).subdivide(n=5)\n",
+    "V, F = app.mesh.cone(height=5,Nr=24,Ny=24,Nb=8,radius=1)\n",
     "app.asset.add.tri(\"cone\", V, F)\n",
     "\n",
     "V, F, T = app.mesh.icosphere(r=0.25, subdiv_count=4).tetrahedralize()\n",
     "app.asset.add.tet(\"sphere\", V, F, T)\n",
     "\n",
-    "scene = app.scene.create(\"smash-vel-5\")\n",
-    "scene.add(\"cone\").scale(0.2).rotate(-90,\"x\").at(0,-1.25,0).pin()\n",
-    "scene.add(\"sphere\").at(0,1,0).pull_pin().hold(1.0).unpin()\n",
+    "scene = app.scene.create(\"needle-sphere\")\n",
+    "scene.add(\"cone\").scale(0.2).rotate(90,\"x\").at(0,-0.25,0).jitter().pin()\n",
+    "scene.add(\"sphere\").at(0,1,0).jitter().pull_pin().hold(1.0).unpin()\n",
     "\n",
     "n, space = 5, 0.05\n",
     "for i in range(n):\n",
     "    y = (i + 1) * space\n",
     "    deg = i * 90 / n\n",
     "    obj = scene.add(\"sheet\").direction([1,0,0],[0,1,0])\n",
-    "    obj.at(0, y, 0).rotate(90,\"x\").rotate(deg,\"y\")\n",
+    "    obj.at(0, y, 0).jitter().rotate(90,\"x\").rotate(deg,\"y\")\n",
     "\n",
     "fixed = scene.build().report()\n",
     "fixed.preview();"
@@ -44,7 +44,7 @@
    "source": [
     "session = app.session.create(\"sphere-needle\").init(fixed)\n",
     "param = app.session.param()\n",
-    "param.set(\"frames\", 100);\n",
+    "param.set(\"frames\", 180);\n",
     "param.set(\"area-density\", 1e3).set(\"volume-density\", 1e5);\n",
     "\n",
     "session.start(param).preview();\n",
diff --git a/examples/stack.ipynb b/examples/stack.ipynb
index abb0516..121bfa0 100644
--- a/examples/stack.ipynb
+++ b/examples/stack.ipynb
@@ -25,7 +25,7 @@
     "    y = (i + 1) * space\n",
     "    deg = i * 90 / n\n",
     "    obj = scene.add(\"sheet\").direction([1,0,0],[0,0,1])\n",
-    "    obj.at(0, y, 0).rotate(deg,\"y\")\n",
+    "    obj.at(0, y, 0).jitter().rotate(deg,\"y\")\n",
     "\n",
     "scene.add(\"sphere\").at(0,1,0).velocity(0,-5,0)\n",
     "\n",
diff --git a/examples/trampoline.ipynb b/examples/trampoline.ipynb
index 276aab9..35c03e4 100644
--- a/examples/trampoline.ipynb
+++ b/examples/trampoline.ipynb
@@ -23,7 +23,7 @@
     "sheet.pin(sheet.grab([-1,0,0])+sheet.grab([1,0,0]))\n",
     "\n",
     "armadillo = scene.add(\"armadillo\").scale(0.75).rotate(180,\"y\")\n",
-    "armadillo.at(0,1,0).velocity(0,-5,0)\n",
+    "armadillo.at(0,1,0).jitter().velocity(0,-5,0)\n",
     "\n",
     "gap = 0.025\n",
     "scene.add_invisible_wall([1+gap,0,0],[-1,0,0])\n",
@@ -47,7 +47,7 @@
     "param.set(\"area-density\", 1e3).set(\"volume-density\", 6e3);\n",
     "param.set(\"area-young-mod\", 10000.0);\n",
     "param.set(\"bend\", 1.0);\n",
-    "param.set(\"frames\", 200);\n",
+    "param.set(\"frames\", 120);\n",
     "\n",
     "session = app.session.create(\"drop-trampoline\").init(fixed)\n",
     "session.start(param).preview();\n",
diff --git a/examples/trapped.ipynb b/examples/trapped.ipynb
index fa54032..b29c8e4 100644
--- a/examples/trapped.ipynb
+++ b/examples/trapped.ipynb
@@ -17,7 +17,7 @@
     "scene = app.scene.create(\"sphere-trap\")\n",
     "\n",
     "scene.add_invisible_sphere([0,0,0],0.7).invert().radius(0.15,3).radius(100,4)\n",
-    "scene.add(\"armadillo\").rotate(180,\"y\")\n",
+    "scene.add(\"armadillo\").jitter().rotate(180,\"y\")\n",
     "\n",
     "fixed = scene.build().report()\n",
     "fixed.preview();"