[FEATURE] Enabling rendering plane geometry one-sided.

genesis/engine/scene.py

@@ -308,7 +308,9 @@ def add_entity(
                 gs.raise_exception(f"Unsupported material for morph: {material} and {morph}.")
 
         if surface.double_sided is None:
-            if isinstance(material, gs.materials.PBD.Cloth):
+            if hasattr(morph, "double_sided"):
+                surface.double_sided = morph.double_sided
+            elif isinstance(material, gs.materials.PBD.Cloth):
                 surface.double_sided = True
             else:
                 surface.double_sided = False

genesis/options/morphs.py

@@ -331,10 +331,14 @@ class Plane(Primitive):
         Whether the entity needs to be visualized. Set it to False if you need a invisible object only for collision purposes. Defaults to True. `visualization` and `collision` cannot both be False. **This is only used for RigidEntity.**
     collision : bool, optional
         Whether the entity needs to be considered for collision checking. Defaults to True. `visualization` and `collision` cannot both be False. **This is only used for RigidEntity.**
+    one_sided : bool, optional
+        Whether the entity needs to be rendered as a one-sided or two-sided plane.
     """
 
     fixed: bool = True
     normal: tuple = (0, 0, 1)
+    one_sided: bool = False
+    double_sided: bool | None = None
 
     def __init__(self, **data):
         super().__init__(**data)
@@ -348,6 +352,8 @@ def __init__(self, **data):
         if self.requires_jac_and_IK:
             gs.raise_exception("`requires_jac_and_IK` must be False for `Plane`.")
 
+        self.double_sided = not self.one_sided
+
         self.normal = tuple(np.array(self.normal) / np.linalg.norm(self.normal))
 
 

genesis/utils/mesh.py

@@ -792,26 +792,54 @@ def create_cylinder(radius, height, sections=None, color=(1.0, 1.0, 1.0, 1.0)):
     return mesh
 
 
-def create_plane(size=1e3, color=None, normal=(0, 0, 1)):
+def create_plane(size=1e3, color=None, normal=(0, 0, 1), one_sided: bool = False):
     thickness = 1e-2  # for safety
-    mesh = trimesh.creation.box(extents=[size, size, thickness])
+    if one_sided:
+        half = size * 0.5
+        verts = np.array(
+            [
+                [-half, -half, 0.0],
+                [half, -half, 0.0],
+                [half, half, 0.0],
+                [-half, -half, 0.0],
+                [half, half, 0.0],
+                [-half, half, 0.0],
+            ],
+            dtype=np.float32,
+        )
+        faces = np.arange(6, dtype=np.int32).reshape(-1, 3)
+        uv = np.array(
+            [
+                [0, 0],
+                [size, 0],
+                [size, size],
+                [0, 0],
+                [size, size],
+                [0, size],
+            ],
+            dtype=np.float32,
+        )
+        mesh = trimesh.Trimesh(verts, faces, process=False)
+    else:
+        mesh = trimesh.creation.box(extents=[size, size, thickness])
+        uv = np.array(
+            [
+                [0, 0],
+                [0, 0],
+                [0, size],
+                [0, size],
+                [size, 0],
+                [size, 0],
+                [size, size],
+                [size, size],
+            ],
+            dtype=np.float32,
+        )
     mesh.vertices[:, 2] -= thickness / 2
     mesh.vertices = gu.transform_by_R(mesh.vertices, gu.z_to_R(normal))
     if color is None:  # use checkerboard texture
         mesh.visual = trimesh.visual.TextureVisuals(
-            uv=np.array(
-                [
-                    [0, 0],
-                    [0, 0],
-                    [0, size],
-                    [0, size],
-                    [size, 0],
-                    [size, 0],
-                    [size, size],
-                    [size, size],
-                ],
-                dtype=np.float32,
-            ),
+            uv=uv,
             material=trimesh.visual.material.SimpleMaterial(
                 image=Image.open(os.path.join(get_assets_dir(), "textures/checker.png")),
             ),

genesis/vis/rasterizer_context.py

@@ -290,6 +290,11 @@ def on_rigid(self):
                         mesh = geom.get_sdf_trimesh()
                     else:
                         mesh = geom.get_trimesh()
+                    if isinstance(rigid_entity.morph, gs.morphs.Plane) and not rigid_entity.morph.double_sided:
+                        mesh = mu.create_plane(one_sided=not rigid_entity.morph.double_sided)
+                    else:
+                        mesh = geom.get_trimesh()
+
                     geom_T = geoms_T[geom.idx][self.rendered_envs_idx]
                     self.rigid_nodes[geom.uid] = self.add_node(
                         pyrender.Mesh.from_trimesh(