frontend api square mesh creation update

README.md

@@ -54,8 +54,8 @@ from frontend import App
 # make an app with the label "drape"
 app = App("drape", renew=True)
 
-# create a square mesh resolution 128
-V, F = app.mesh.square(res=128)
+# create a square mesh resolution 128 spanning the xz plane
+V, F = app.mesh.square(res=128, ex=[1,0,0], ey=[0,0,1])
 
 # add to the asset and name it "sheet"
 app.asset.add.tri("sheet", V, F)
@@ -77,11 +77,11 @@ for i in range(5):
     # add a sheet to the scene
     obj = scene.add("sheet")
 
-    # pick two vertices max towards directions [1,-1,0] and [-1,-1,0]
-    corner = obj.grab([1, -1, 0]) + obj.grab([-1, -1, 0])
+    # pick two vertices max towards directions [1,0,-1] and [-1,0,-1]
+    corner = obj.grab([1, 0, -1]) + obj.grab([-1, 0, -1])
 
-    # place it with a vertical offset, rotate it and pin the corners
-    obj.at(0, gap * i, 0).rotate(90, "x").pin(corner)
+    # place it with a vertical offset and pin the corners
+    obj.at(0, gap * i, 0).pin(corner)
 
     # set fiber directions required for the Baraff-Witkin model
     obj.direction([1, 0, 0], [0, 0, 1])

examples/curtain.ipynb

@@ -11,7 +11,7 @@
     "\n",
     "app = App(\"curtain\", renew=True)\n",
     "\n",
-    "V, F = app.mesh.square(res=64)\n",
+    "V, F = app.mesh.square(res=64,ex=[0,0,1],ey=[0,1,0])\n",
     "app.asset.add.tri(\"sheet\", V, F)\n",
     "\n",
     "V, F = app.mesh.icosphere(r=0.5, subdiv_count=4)\n",
@@ -22,7 +22,7 @@
     "space = 0.25\n",
     "for i in range(15):\n",
     "    obj = scene.add(\"sheet\")\n",
-    "    obj.at(i * space, 0, 0).rotate(90, \"y\")\n",
+    "    obj.at(i * space, 0, 0)\n",
     "    obj.direction([0,1,0],[0,0,1])\n",
     "    obj.pin(obj.grab([0, 1, 0]))\n",
     "\n",

examples/drape.ipynb

@@ -13,8 +13,8 @@
     "# make an app with the label \"drape\"\n",
     "app = App(\"drape\", renew=True)\n",
     "\n",
-    "# create a square mesh resolution 128\n",
-    "V, F = app.mesh.square(res=128)\n",
+    "# create a square mesh resolution 128 spanning the xz plane\n",
+    "V, F = app.mesh.square(res=128, ex=[1,0,0], ey=[0,0,1])\n",
     "\n",
     "# add to the asset and name it \"sheet\"\n",
     "app.asset.add.tri(\"sheet\", V, F)\n",
@@ -37,10 +37,10 @@
     "    obj = scene.add(\"sheet\")\n",
     "\n",
     "    # pick two corners\n",
-    "    corner = obj.grab([1, -1, 0]) + obj.grab([-1, -1, 0])\n",
+    "    corner = obj.grab([1, 0, -1]) + obj.grab([-1, 0, -1])\n",
     "\n",
-    "    # place it with an vertical offset, rorate it and pin the corners\n",
-    "    obj.at(0, gap * i, 0).rotate(90, \"x\").pin(corner)\n",
+    "    # place it with an vertical offset and pin the corners\n",
+    "    obj.at(0, gap * i, 0).pin(corner)\n",
     "\n",
     "    # set fiber directions required for Baraff-Witkin\n",
     "    obj.direction([1, 0, 0], [0, 0, 1])\n",

examples/frontend/_mesh_.py

@@ -26,7 +26,12 @@ def box(self, width: float = 1, height: float = 1, depth: float = 1) -> "TriMesh
         )
 
     def rectangle(
-        self, res_x: int = 32, width: float = 2, height: float = 1
+        self,
+        res_x: int = 32,
+        width: float = 2,
+        height: float = 1,
+        ex: list[float] = [1, 0, 0],
+        ey: list[float] = [0, 1, 0],
     ) -> "TriMesh":
         ratio = height / width
         res_y = int(res_x * ratio)
@@ -38,6 +43,10 @@ def rectangle(
         X_flat, Y_flat = X.flatten(), Y.flatten()
         Z_flat = np.full_like(X_flat, 0)
         vert = np.vstack((X_flat, Y_flat, Z_flat)).T
+        _ex, _ey = np.array(ex), np.array(ey)
+        for i, v in enumerate(vert):
+            x, y, _ = v
+            vert[i] = _ex * x + _ey * y
         n_faces = 2 * (res_x - 1) * (res_y - 1)
         tri = np.zeros((n_faces, 3), dtype=np.int32)
         tri_idx = 0
@@ -56,8 +65,14 @@ def rectangle(
                 tri_idx += 2
         return TriMesh.create(vert, tri, self._cache_dir)
 
-    def square(self, res: int = 32, size: float = 2) -> "TriMesh":
-        return self.rectangle(res, size, size)
+    def square(
+        self,
+        res: int = 32,
+        size: float = 2,
+        ex: list[float] = [1, 0, 0],
+        ey: list[float] = [0, 1, 0],
+    ) -> "TriMesh":
+        return self.rectangle(res, size, size, ex, ey)
 
     def circle(self, n: int = 32, r: float = 1, ntri: int = 1024) -> "TriMesh":
         pts = []

examples/hang.ipynb

@@ -11,7 +11,7 @@
     "\n",
     "app = App(\"hang\", renew=True)\n",
     "\n",
-    "V, F = app.mesh.square(res=128)\n",
+    "V, F = app.mesh.square(res=128,ex=[1,0,0],ey=[0,1,0])\n",
     "app.asset.add.tri(\"sheet\", V, F)\n",
     "\n",
     "scene = app.scene.create(\"hang-sheet\")\n",

examples/headless.py

@@ -3,7 +3,7 @@
 
 app = App("headless").clear()
 
-V, F = app.mesh.square(res=64)
+V, F = app.mesh.square(res=64,ex=[0,0,1],ey=[0,1,0])
 app.asset.add.tri("sheet", V, F)
 
 V, F = app.mesh.icosphere(r=0.5, subdiv_count=4)
@@ -14,7 +14,7 @@
 space = 0.25
 for i in range(5):
     obj = scene.add("sheet")
-    obj.at(i * space, 0, 0).rotate(90, "y")
+    obj.at(i * space, 0, 0)
     obj.direction([0, 1, 0], [0, 0, 1])
     obj.pin(obj.grab([0, 1, 0]))
 

examples/stack.ipynb

@@ -11,7 +11,7 @@
     "\n",
     "app = App(\"stack\", renew=True)\n",
     "\n",
-    "V, F = app.mesh.square(res=128)\n",
+    "V, F = app.mesh.square(res=128,ex=[1,0,0],ey=[0,0,1])\n",
     "app.asset.add.tri(\"sheet\", V, F)\n",
     "\n",
     "V, F, T = app.mesh.icosphere(r=0.25, subdiv_count=4).tetrahedralize()\n",
@@ -24,8 +24,8 @@
     "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 = scene.add(\"sheet\").direction([1,0,0],[0,0,1])\n",
+    "    obj.at(0, y, 0).rotate(deg,\"y\")\n",
     "\n",
     "scene.add(\"sphere\").at(0,1,0).velocity(0,-5,0)\n",
     "\n",

examples/trampoline.ipynb

@@ -11,15 +11,15 @@
     "\n",
     "app = App(\"trampoline\", renew=True)\n",
     "\n",
-    "V, F = app.mesh.square(res=128)\n",
+    "V, F = app.mesh.square(res=128,ex=[1,0,0],ey=[0,0,1])\n",
     "app.asset.add.tri(\"sheet\", V, F)\n",
     "\n",
     "V, F, T = app.mesh.preset(\"armadillo\").decimate(30000).tetrahedralize().normalize()\n",
     "app.asset.add.tet(\"armadillo\", V, F, T)\n",
     "\n",
     "scene = app.scene.create(\"drop-vel-5\")\n",
     "\n",
-    "sheet = scene.add(\"sheet\").direction([1,0,0],[0,1,0]).rotate(90,\"x\")\n",
+    "sheet = scene.add(\"sheet\").direction([1,0,0],[0,0,1])\n",
     "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",