Distinguish user-specified material from default.

genesis/engine/entities/base_entity.py

@@ -19,6 +19,96 @@ def __init__(
         material,
         surface,
     ):
+        if isinstance(material, gs.materials.Rigid):
+            # small sdf res is sufficient for primitives regardless of size
+            if isinstance(morph, gs.morphs.Primitive):
+                material._sdf_max_res = 32
+
+        # some morph should not smooth surface normal
+        if isinstance(morph, (gs.morphs.Box, gs.morphs.Cylinder, gs.morphs.Terrain)):
+            surface.smooth = False
+
+        if isinstance(morph, (gs.morphs.URDF, gs.morphs.MJCF, gs.morphs.Terrain)):
+            if not isinstance(material, (gs.materials.Rigid, gs.materials.Avatar, gs.materials.Hybrid)):
+                gs.raise_exception(f"Unsupported material for morph: {material} and {morph}.")
+
+        if surface.double_sided is None:
+            surface.double_sided = isinstance(material, gs.materials.PBD.Cloth)
+
+        # validate and populate default surface.vis_mode considering morph type
+        if isinstance(material, (gs.materials.Rigid, gs.materials.Avatar, gs.materials.Tool)):
+            if surface.vis_mode is None:
+                surface.vis_mode = "visual"
+
+            if surface.vis_mode not in ("visual", "collision", "sdf"):
+                gs.raise_exception(
+                    f"Invalid `surface.vis_mode` for material {material}: '{surface.vis_mode}'. Only supporting "
+                    "'visual', 'collision' and 'sdf'."
+                )
+        elif isinstance(
+            material,
+            (
+                gs.materials.PBD.Liquid,
+                gs.materials.PBD.Particle,
+                gs.materials.MPM.Liquid,
+                gs.materials.MPM.Sand,
+                gs.materials.MPM.Snow,
+                gs.materials.SPH.Liquid,
+            ),
+        ):
+            if surface.vis_mode is None:
+                surface.vis_mode = "particle"
+
+            if surface.vis_mode not in ("particle", "recon"):
+                gs.raise_exception(
+                    f"Invalid `surface.vis_mode` for material {material}: '{surface.vis_mode}'. Only supporting "
+                    "'particle' and 'recon'."
+                )
+        elif isinstance(material, (gs.materials.SF.Smoke)):
+            if surface.vis_mode is None:
+                surface.vis_mode = "particle"
+
+            if surface.vis_mode not in ("particle",):
+                gs.raise_exception(
+                    f"Invalid `surface.vis_mode` for material {material}: '{surface.vis_mode}'. Only supporting "
+                    "'particle'."
+                )
+        elif isinstance(material, (gs.materials.PBD.Base, gs.materials.MPM.Base, gs.materials.SPH.Base)):
+            if surface.vis_mode is None:
+                surface.vis_mode = "visual"
+
+            if surface.vis_mode not in ("visual", "particle", "recon"):
+                gs.raise_exception(
+                    f"Invalid `surface.vis_mode` for material {material}: '{surface.vis_mode}'. Only supporting "
+                    "'visual', 'particle' and 'recon'."
+                )
+        elif isinstance(material, (gs.materials.FEM.Base)):
+            if surface.vis_mode is None:
+                surface.vis_mode = "visual"
+
+            if surface.vis_mode not in ("visual",):
+                gs.raise_exception(
+                    f"Invalid `surface.vis_mode` for material {material}: '{surface.vis_mode}'. Only supporting "
+                    "'visual'."
+                )
+        elif isinstance(material, (gs.materials.Hybrid)):  # determine the visual of the outer soft part
+            if surface.vis_mode is None:
+                surface.vis_mode = "particle"
+
+            if surface.vis_mode not in ["particle", "visual"]:
+                gs.raise_exception(
+                    f"Invalid `surface.vis_mode` for material {material}: '{surface.vis_mode}'. Only supporting "
+                    "'particle' and 'visual'."
+                )
+        else:
+            gs.raise_exception(f"Material not supported.: {material}")
+
+        # Set material-dependent default options
+        if isinstance(morph, gs.morphs.FileMorph):
+            # Rigid entities will convexify geom by default
+            if morph.convexify is None:
+                morph.convexify = isinstance(material, (gs.materials.Rigid, gs.materials.Avatar))
+
         self._uid = gs.UID()
         self._idx = idx
         self._scene = scene

genesis/engine/entities/rigid_entity/rigid_entity.py

@@ -1,6 +1,7 @@
 from copy import copy
 from itertools import chain
 from typing import Literal
+from typing import TYPE_CHECKING
 
 import numpy as np
 import taichi as ti
@@ -25,6 +26,10 @@
 from .rigid_joint import RigidJoint
 from .rigid_link import RigidLink
 
+if TYPE_CHECKING:
+    from genesis.engine.solvers.base_solver import Solver
+    from genesis.engine.scene import Scene
+
 
 @ti.data_oriented
 class RigidEntity(Entity):
@@ -57,6 +62,9 @@ def __init__(
         equality_start=0,
         visualize_contact=False,
     ):
+        if material is None:
+            material = gs.materials.Rigid()
+
         super().__init__(idx, scene, morph, solver, material, surface)
 
         self._idx_in_solver = idx_in_solver
@@ -83,36 +91,29 @@ def __init__(
 
         self._is_built = False
 
-        self._load_model()
+        self._load_model(morph, material, self.surface)
 
-    def _load_model(self):
+    def _load_model(self, morph, material, surface):
         self._links = gs.List()
         self._joints = gs.List()
         self._equalities = gs.List()
 
-        if isinstance(self._morph, gs.morphs.Mesh):
-            self._load_mesh(self._morph, self._surface)
-        elif isinstance(self._morph, (gs.morphs.MJCF, gs.morphs.URDF, gs.morphs.Drone)):
-            self._load_scene(self._morph, self._surface)
-        elif isinstance(self._morph, gs.morphs.Primitive):
-            self._load_primitive(self._morph, self._surface)
-        elif isinstance(self._morph, gs.morphs.Terrain):
-            self._load_terrain(self._morph, self._surface)
+        if isinstance(morph, gs.morphs.Mesh):
+            self._load_mesh(morph, material, surface)
+        elif isinstance(morph, (gs.morphs.MJCF, gs.morphs.URDF, gs.morphs.Drone)):
+            self._load_scene(morph, material, surface)
+        elif isinstance(morph, gs.morphs.Primitive):
+            self._load_primitive(morph, material, surface)
+        elif isinstance(morph, gs.morphs.Terrain):
+            self._load_terrain(morph, material, surface)
         else:
-            gs.raise_exception(f"Unsupported morph: {self._morph}.")
+            gs.raise_exception(f"Unsupported morph: {morph}.")
 
-        self._requires_jac_and_IK = self._morph.requires_jac_and_IK
+        self._requires_jac_and_IK = morph.requires_jac_and_IK
 
         self._update_child_idxs()
 
-    def _update_child_idxs(self):
-        for link in self._links:
-            if link.parent_idx != -1:
-                parent_link = self._links[link.parent_idx_local]
-                if link.idx not in parent_link.child_idxs:
-                    parent_link.child_idxs.append(link.idx)
-
-    def _load_primitive(self, morph, surface):
+    def _load_primitive(self, morph, material, surface):
         if morph.fixed:
             joint_type = gs.JOINT_TYPE.FIXED
             n_qs = 0
@@ -180,7 +181,7 @@ def _load_primitive(self, morph, surface):
         link, (joint,) = self._add_by_info(
             l_info=dict(
                 is_robot=False,
-                name=f"{link_name_prefix}_baselink",
+                name=f"{link_name_prefix}_base",
                 pos=np.array(morph.pos),
                 quat=np.array(morph.quat),
                 inertial_pos=gu.zero_pos(),
@@ -189,7 +190,7 @@ def _load_primitive(self, morph, surface):
             ),
             j_infos=[
                 dict(
-                    name=f"{link_name_prefix}_baselink_joint",
+                    name=f"{link_name_prefix}_root_joint",
                     n_qs=n_qs,
                     n_dofs=n_dofs,
                     type=joint_type,
@@ -198,10 +199,10 @@ def _load_primitive(self, morph, surface):
             ],
             g_infos=g_infos,
             morph=morph,
-            surface=surface,
+            material=material,
         )
 
-    def _load_mesh(self, morph, surface):
+    def _load_mesh(self, morph, material, surface):
         if morph.fixed:
             joint_type = gs.JOINT_TYPE.FIXED
             n_qs = 0
@@ -247,12 +248,13 @@ def _load_mesh(self, morph, surface):
                     )
                 )
 
-        link_name = morph.file.rsplit("/", 1)[-1].replace(".", "_")
+        *_, link_name = morph.file.rsplit("/", 1)
+        link_name.replace(".", "_")
 
         link, (joint,) = self._add_by_info(
             l_info=dict(
                 is_robot=False,
-                name=f"{link_name}_baselink",
+                name=f"{link_name}_base",
                 pos=np.array(morph.pos),
                 quat=np.array(morph.quat),
                 inertial_pos=gu.zero_pos(),
@@ -261,7 +263,7 @@ def _load_mesh(self, morph, surface):
             ),
             j_infos=[
                 dict(
-                    name=f"{link_name}_baselink_joint",
+                    name=f"{link_name}_root_joint",
                     n_qs=n_qs,
                     n_dofs=n_dofs,
                     type=joint_type,
@@ -270,10 +272,10 @@ def _load_mesh(self, morph, surface):
             ],
             g_infos=g_infos,
             morph=morph,
-            surface=surface,
+            material=material,
         )
 
-    def _load_terrain(self, morph, surface):
+    def _load_terrain(self, morph, material, surface):
         vmesh, mesh, self.terrain_hf = tu.parse_terrain(morph, surface)
         self.terrain_scale = np.array((morph.horizontal_scale, morph.vertical_scale), dtype=gs.np_float)
 
@@ -300,7 +302,7 @@ def _load_terrain(self, morph, surface):
         link, (joint,) = self._add_by_info(
             l_info=dict(
                 is_robot=False,
-                name="baselink",
+                name="base",
                 pos=np.array(morph.pos),
                 quat=np.array(morph.quat),
                 inertial_pos=None,
@@ -312,18 +314,18 @@ def _load_terrain(self, morph, surface):
             ),
             j_infos=[
                 dict(
-                    name="joint_baselink",
+                    name="root_joint",
                     n_qs=0,
                     n_dofs=0,
                     type=gs.JOINT_TYPE.FIXED,
                 )
             ],
             g_infos=g_infos,
             morph=morph,
-            surface=surface,
+            material=material,
         )
 
-    def _load_scene(self, morph, surface):
+    def _load_scene(self, morph, material, surface):
         # Mujoco's unified MJCF+URDF parser is not good enough for now to be used for loading both MJCF and URDF files.
         # First, it would happen when loading visual meshes having supported format (i.e. Collada files '.dae').
         # Second, it does not take into account URDF 'mimic' joint constraints. However, it does a better job at
@@ -517,7 +519,7 @@ def _load_scene(self, morph, surface):
             # Exclude joints with 0 dofs to align with Mujoco
             link_j_infos = [j_info for j_info in link_j_infos if j_info["n_dofs"] > 0]
 
-            self._add_by_info(l_info, link_j_infos, link_g_infos, morph, surface)
+            self._add_by_info(l_info, link_j_infos, link_g_infos, morph, material)
 
         # Add equality constraints sequentially
         for eq_info in eqs_info:
@@ -529,6 +531,13 @@ def _load_scene(self, morph, surface):
                 sol_params=eq_info["sol_params"],
             )
 
+    def _update_child_idxs(self):
+        for link in self._links:
+            if link.parent_idx != -1:
+                parent_link = self._links[link.parent_idx_local]
+                if link.idx not in parent_link.child_idxs:
+                    parent_link.child_idxs.append(link.idx)
+
     def _build(self):
         for link in self._links:
             link._build()
@@ -600,7 +609,7 @@ def _init_jac_and_IK(self):
             dtype=gs.ti_float, shape=self._solver._batch_shape((self.n_dofs, self._IK_error_dim))
         )
 
-    def _add_by_info(self, l_info, j_infos, g_infos, morph, surface):
+    def _add_by_info(self, l_info, j_infos, g_infos, morph, material):
         if len(j_infos) > 1 and any(j_info["type"] in (gs.JOINT_TYPE.FREE, gs.JOINT_TYPE.FIXED) for j_info in j_infos):
             raise ValueError(
                 "Compounding joints of types 'FREE' or 'FIXED' with any other joint on the same body not supported"
@@ -760,9 +769,10 @@ def _add_by_info(self, l_info, j_infos, g_infos, morph, surface):
 
         # Add collision geometries
         for g_info in cg_infos:
-            friction = g_info.get("friction", self.material.friction)
-            if friction is None:
-                friction = gu.default_friction()
+            if material is not None:
+                friction = material.friction
+            else:
+                friction = g_info.get("friction", self.material.friction)
             link._add_geom(
                 mesh=g_info["mesh"],
                 init_pos=g_info.get("pos", gu.zero_pos()),

genesis/engine/entities/tool_entity/tool_entity.py

@@ -18,15 +18,7 @@
 @ti.data_oriented
 class ToolEntity(Entity):
     # Mesh-based tool body entity
-    def __init__(
-        self,
-        scene,
-        idx,
-        solver,
-        material,
-        morph,
-        surface,
-    ):
+    def __init__(self, scene, idx, solver, material, morph, surface):
         super().__init__(idx, scene, morph, solver, material, surface)
 
         self._init_pos = np.array(morph.pos, dtype=gs.np_float)

genesis/engine/materials/rigid.py

@@ -20,7 +20,7 @@ class Rigid(Material):
         rho : float, optional
             The density of the material used to compute mass. Default is 200.0.
         friction : float, optional
-            Friction coefficient within the rigid solver. If None, a default of 1.0 may be used or parsed from file.
+            Friction coefficient within the rigid solver. Default is 1.0.
         needs_coup : bool, optional
             Whether the material participates in coupling with other solvers. Default is True.
         coup_friction : float, optional
@@ -42,7 +42,7 @@ class Rigid(Material):
     def __init__(
         self,
         rho=200.0,
-        friction=None,
+        friction=1.0,
         needs_coup=True,
         coup_friction=0.1,
         coup_softness=0.002,
@@ -54,9 +54,8 @@ def __init__(
     ):
         super().__init__()
 
-        if friction is not None:
-            if friction < 1e-2 or friction > 5.0:
-                gs.raise_exception("`friction` must be in the range [1e-2, 5.0] for simulation stability.")
+        if friction < 1e-2 or friction > 5.0:
+            gs.raise_exception("`friction` must be in the range [1e-2, 5.0] for simulation stability.")
 
         if coup_friction < 0:
             gs.raise_exception("`coup_friction` must be non-negative.")
@@ -76,7 +75,7 @@ def __init__(
         if sdf_min_res > sdf_max_res:
             gs.raise_exception("`sdf_min_res` must be smaller than or equal to `sdf_max_res`.")
 
-        self._friction = float(friction) if friction is not None else None
+        self._friction = float(friction)
         self._needs_coup = bool(needs_coup)
         self._coup_friction = float(coup_friction)
         self._coup_softness = float(coup_softness)