from __future__ import annotations import numpy as np import os from .message import success from .robot import Robot, Link, Part, Joint from .config import Config from .geometry import Box, Cylinder, Sphere, Mesh, Shape from .exporter import Exporter from .exporter_utils import xml_escape, rotation_matrix_to_rpy MODEL_CONFIG_XML = """ %s 1.0 %s """ class ExporterSDF(Exporter): def __init__(self, config: Config | None = None): super().__init__() self.config: Config = config self.ext: str = "sdf" self.no_dynamics: bool = False self.additional_xml: str = "" if config is not None: self.no_dynamics = config.no_dynamics additional_xml_file = config.get("additional_xml", None, required=False) if isinstance(additional_xml_file, str): self.add_additional_xml(additional_xml_file) elif isinstance(additional_xml_file, list): for filename in additional_xml_file: self.add_additional_xml(filename) def add_additional_xml(self, xml_file: str): self.additional_xml += f"" with open(self.config.output_directory + "/" + xml_file, "r") as file: self.additional_xml += file.read() def append(self, line: str): self.xml += line def build(self, robot: Robot): self.xml = "" self.append('') self.append("") if self.config: self.append(f"") self.append('') self.append(f'') for base_link in robot.base_links: self.add_link(robot, base_link) if self.additional_xml: self.append(self.additional_xml) self.append("") self.append("") return self.xml def add_inertial( self, mass: float, com: np.ndarray, inertia: np.ndarray, frame: str = "" ): # Unless "no_dynamics" is set, we make sure that mass and inertia # are not zero if not self.no_dynamics: mass = max(1e-9, mass) inertia[0, 0] = max(1e-9, inertia[0, 0]) inertia[1, 1] = max(1e-9, inertia[1, 1]) inertia[2, 2] = max(1e-9, inertia[2, 2]) self.append("") self.append( '%g %g %g 0 0 0' % self.config.round(( com[0], com[1], com[2], )) ) self.append("%g" % self.config.round(mass)) self.append( "%g%g%g%g%g%g" % self.config.round(( inertia[0, 0], inertia[0, 1], inertia[0, 2], inertia[1, 1], inertia[1, 2], inertia[2, 2], )) ) self.append("") def append_material(self, color: np.ndarray): self.append(f"") self.append("%g %g %g %g" % self.config.round((color[0], color[1], color[2], color[3]))) self.append("%g %g %g %g" % self.config.round((color[0], color[1], color[2], color[3]))) self.append("0.1 0.1 0.1 1") self.append("0 0 0 0") self.append("") def add_mesh( self, link: Link, part: Part, node: str, T_world_link: np.ndarray, mesh: Mesh, mesh_n: int, ): """ Add a mesh node (e.g. STL) to the SDF file """ self.append(f'<{node} name="{part.name}_{node}_mesh_{mesh_n}">') T_link_part = np.linalg.inv(T_world_link) @ part.T_world_part self.append(self.pose(T_link_part, relative_to=link.name)) mesh_file = mesh.filename self.append("") self.append( f"model://{self.config.robot_name}/{xml_escape(mesh_file)}" ) self.append("") if node == "visual": self.append_material(mesh.color) # Apply properties based on node type (visual or collision) properties = mesh.visual_properties if node == "visual" else mesh.collision_properties for key, value in properties.items(): self.append(f'<{key}>{xml_escape(str(value))}') self.append(f"") def add_shape( self, link: Link, part: Part, node: str, T_world_link: np.ndarray, shape: Shape, shape_n: int, ): """ Add shapes (box, sphere and cylinder) nodes to the SDF. """ self.append(f'<{node} name="{part.name}_{node}_shapes_{shape_n}">') T_link_shape = ( np.linalg.inv(T_world_link) @ part.T_world_part @ shape.T_part_shape ) self.append(self.pose(T_link_shape, relative_to=link.name)) self.append("") if isinstance(shape, Box): self.append("%g %g %g" % self.config.round(tuple(shape.size))) elif isinstance(shape, Cylinder): self.append( "%g%g" % self.config.round((shape.length, shape.radius)) ) elif isinstance(shape, Sphere): self.append("%g" % self.config.round((shape.radius,))) self.append("") if node == "visual": self.append_material(shape.color) # Apply properties based on node type (visual or collision) properties = shape.visual_properties if node == "visual" else shape.collision_properties for key, value in properties.items(): self.append(f'<{key}>{xml_escape(str(value))}') self.append(f"") def add_geometries(self, link: Link, part: Part, T_world_link: np.ndarray): """ Add a part geometries """ shape_n = 0 for shape in part.shapes: if shape.visual: shape_n += 1 self.add_shape(link, part, "visual", T_world_link, shape, shape_n) if shape.collision: shape_n += 1 self.add_shape(link, part, "collision", T_world_link, shape, shape_n) mesh_n = 0 for mesh in part.meshes: if mesh.visual: mesh_n += 1 self.add_mesh(link, part, "visual", T_world_link, mesh, mesh_n) if mesh.collision: mesh_n += 1 self.add_mesh(link, part, "collision", T_world_link, mesh, mesh_n) def add_joint(self, joint: Joint, T_world_link: np.ndarray): self.append(f"") joint_type = joint.properties.get("type", joint.joint_type) self.append(f'') T_link_joint = np.linalg.inv(T_world_link) @ joint.T_world_joint self.append(self.pose(T_link_joint, relative_to=joint.parent.name)) self.append(f"{joint.parent.name}") self.append(f"{joint.child.name}") self.append("") self.append("%g %g %g" % self.config.round(tuple(joint.axis))) self.append("") if "max_effort" in joint.properties: self.append("%g" % self.config.round(joint.properties["max_effort"])) else: self.append("10") if "max_velocity" in joint.properties: self.append("%g" % self.config.round(joint.properties["max_velocity"])) else: self.append("10") joint_limits = joint.properties.get("limits", joint.limits) if joint_limits is None: if joint_type == "revolute": joint_limits = [-np.pi, np.pi] if joint_type == "prismatic": joint_limits = [-1, 1] self.append(f"{joint_limits[0]}") self.append(f"{joint_limits[1]}") self.append("") if joint.relation is not None: self.append( f'{joint.relation.ratio}' ) self.append("") self.append(f"{joint.properties.get('friction', 0.)}") self.append(f"{joint.properties.get('damping', 0.)}") self.append("") self.append("") self.append("") def add_frame( self, link: Link, frame: str, T_world_link: np.ndarray, T_world_frame: np.ndarray, ): self.append(f"") T_link_frame = np.linalg.inv(T_world_link) @ T_world_frame self.append(f'') self.append(self.pose(T_link_frame, relative_to=link.name)) self.append("") def add_link(self, robot: Robot, link: Link, joint: Joint = None): """ Adds a link recursively to the SDF file """ self.append(f"") self.append(f'') T_world_link = np.eye(4) if joint is not None: T_world_link = joint.T_world_joint # Adding inertial properties mass, com, inertia = link.get_dynamics(T_world_link) self.add_inertial(mass, com, inertia, link.name) relative_to = "" if joint is not None: relative_to = joint.name self.append(self.pose(np.eye(4), relative_to=relative_to)) # Adding geometry objects for part in link.parts: self.append(f"") self.add_geometries(link, part, T_world_link) self.append("") if link.fixed: self.append(f'') self.append(f"world") self.append(f"{link.name}") self.append("") # Adding frames attached to current link for frame, T_world_frame in link.frames.items(): self.add_frame(link, frame, T_world_link, T_world_frame) # Adding joints and children links for joint in robot.get_link_joints(link): self.add_link(robot, joint.child, joint) self.add_joint(joint, T_world_link) def pose(self, matrix: np.ndarray, relative_to: str = ""): """ Transforms a transformation matrix into a SDF pose tag """ relative = "" if relative_to: relative = f' relative_to="{relative_to}"' sdf = "%g %g %g %g %g %g" return sdf % (relative, *self.config.round((*matrix[:3, 3], *rotation_matrix_to_rpy(matrix)))) def write_xml(self, robot: Robot, filename: str) -> str: model_config = MODEL_CONFIG_XML % (robot.name, os.path.basename(filename)) super().write_xml(robot, filename) dirname = os.path.dirname(filename) with open(dirname + "/model.config", "w") as file: file.write(model_config) print(success(f"* Writing model.config"))