# Copyright (c) 2025, NVIDIA CORPORATION. All rights reserved. # # NVIDIA CORPORATION and its licensors retain all intellectual property # and proprietary rights in and to this software, related documentation # and any modifications thereto. Any use, reproduction, disclosure or # distribution of this software and related documentation without an express # license agreement from NVIDIA CORPORATION is strictly prohibited. # ''' Utility functions for visualization using meshcat. Installation: pip install trimesh==4.5.3 objaverse==0.1.7 meshcat==0.0.12 webdataset==0.2.111 NOTE: Start meshcat server (in a different terminal) before running this script: meshcat-server ''' import numpy as np import meshcat import meshcat.geometry as g import meshcat.transformations as mtf import trimesh import trimesh.transformations as tra from typing import List, Optional, Tuple, Union, Any control_points_franka = np.array([ [ 0.05268743, -0.00005996, 0.05900000], [-0.05268743, 0.00005996, 0.05900000], [ 0.05268743, -0.00005996, 0.10527314], [-0.05268743, 0.00005996, 0.10527314] ]) control_points_robotiq2f140 = np.array([ [ 0.06801729, -0, 0.0975], [-0.06801729, 0, 0.0975], [ 0.06801729, -0, 0.1950], [-0.06801729, 0, 0.1950] ]) control_points_suction = np.array([ [ 0, 0, -0.10], [ 0, 0, -0.05], [ 0, 0, 0], ]) control_points_data = { "franka": control_points_franka, "robotiq2f140": control_points_robotiq2f140, "suction": control_points_suction, } def get_gripper_control_points(gripper_name: str = 'franka') -> np.ndarray: """ Get the control points for a specific gripper. Args: gripper_name (str): Name of the gripper ("franka", "robotiq2f140", "suction") Returns: np.ndarray: Array of control points for the specified gripper Raises: NotImplementedError: If the specified gripper is not implemented """ if gripper_name in control_points_data: return control_points_data[gripper_name] else: raise NotImplementedError(f"Gripper {gripper_name} is not implemented.") return control_points def get_gripper_depth(gripper_name: str) -> float: """ Get the depth parameter for a specific gripper type. Args: gripper_name (str): Name of the gripper ("franka", "robotiq2f140", "suction") Returns: float: Depth parameter for the specified gripper Raises: NotImplementedError: If the specified gripper is not implemented """ # TODO: Use register module. Don't have this if-else name lookup pts, d = None, None if gripper_name in ["franka", "robotiq2f140"]: pts = get_gripper_control_points(gripper_name) elif gripper_name == "suction": return 0.069 else: raise NotImplementedError(f"Control points for gripper {gripper_name} not implemented!") d = pts[-1][-1] if pts is not None else d return d def get_gripper_offset(gripper_name: str) -> np.ndarray: """ Get the offset transform for a specific gripper type. Args: gripper_name (str): Name of the gripper Returns: np.ndarray: 4x4 homogeneous transformation matrix representing the gripper offset """ return np.eye(4) def load_visualize_control_points_suction() -> np.ndarray: """ Load visualization control points specific to the suction gripper. Returns: np.ndarray: Array of control points for suction gripper visualization """ h = 0 pts = [ [0.0, 0], ] pts = [generate_circle_points(c, radius=0.005) for c in pts] pts = np.stack(pts) ptsz = h * np.ones([pts.shape[0], pts.shape[1], 1]) pts = np.concatenate([pts, ptsz], axis=2) return pts def generate_circle_points(center: List[float], radius: float = 0.007, N: int = 30) -> np.ndarray: """ Generate points forming a circle in 2D space. Args: center (List[float]): Center coordinates [x, y] of the circle radius (float): Radius of the circle N (int): Number of points to generate around the circle Returns: np.ndarray: Array of shape (N, 2) containing the circle points """ angles = np.linspace(0, 2 * np.pi, N, endpoint=False) x_points = center[0] + radius * np.cos(angles) y_points = center[1] + radius * np.sin(angles) points = np.stack((x_points, y_points), axis=1) return points def get_gripper_visualization_control_points(gripper_name: str = 'franka') -> List[np.ndarray]: """ Get control points for visualizing a specific gripper type. Args: gripper_name (str): Name of the gripper ("franka", "robotiq2f140", "suction") Returns: List[np.ndarray]: List of control point arrays for gripper visualization """ if gripper_name == "suction": control_points = load_visualize_control_points_suction() offset = get_gripper_offset('suction') ctrl_pts = [tra.transform_points(cpt, offset) for cpt in control_points] d = get_gripper_depth(gripper_name) line_pts = np.array([[0,0,0], [0,0,d]]) line_pts = np.expand_dims(line_pts, 0) line_pts = [tra.transform_points(cpt, offset) for cpt in line_pts] line_pts = line_pts[0] ctrl_pts.append(line_pts) return ctrl_pts else: control_points = get_gripper_control_points(gripper_name) mid_point = (control_points[0] + control_points[1]) / 2 control_points = [ control_points[-2], control_points[0], mid_point, [0, 0, 0], mid_point, control_points[1], control_points[-1] ] return [control_points, ] def get_color_from_score(labels: Union[float, np.ndarray], use_255_scale: bool = False) -> np.ndarray: """ Convert score labels to RGB colors for visualization. Args: labels (Union[float, np.ndarray]): Score values between 0 and 1 use_255_scale (bool): If True, output colors in [0-255] range, else [0-1] Returns: np.ndarray: RGB colors corresponding to the input scores """ scale = 255.0 if use_255_scale else 1.0 if type(labels) in [np.float32, float]: return scale * np.array([1 - labels, labels, 0]) else: scale = 255.0 if use_255_scale else 1.0 score = scale * np.stack( [np.ones(labels.shape[0]) - labels, labels, np.zeros(labels.shape[0])], axis=1, ) return score.astype(np.int) def trimesh_to_meshcat_geometry(mesh: trimesh.Trimesh) -> g.TriangularMeshGeometry: """ Convert a trimesh mesh to meshcat geometry format. Args: mesh (trimesh.Trimesh): Input mesh in trimesh format Returns: g.TriangularMeshGeometry: Mesh in meshcat geometry format """ return meshcat.geometry.TriangularMeshGeometry(mesh.vertices, mesh.faces) def visualize_mesh( vis: meshcat.Visualizer, name: str, mesh: trimesh.Trimesh, color: Optional[List[int]] = None, transform: Optional[np.ndarray] = None ) -> None: """ Visualize a mesh in meshcat with optional color and transform. Args: vis (meshcat.Visualizer): Meshcat visualizer instance name (str): Name/path for the mesh in the visualizer scene mesh (trimesh.Trimesh): Mesh to visualize color (Optional[List[int]]): RGB color values [0-255]. Random if None transform (Optional[np.ndarray]): 4x4 homogeneous transform matrix """ if vis is None: return if color is None: color = np.random.randint(low=0, high=256, size=3) mesh_vis = trimesh_to_meshcat_geometry(mesh) color_hex = rgb2hex(tuple(color)) material = meshcat.geometry.MeshPhongMaterial(color=color_hex) vis[name].set_object(mesh_vis, material) if transform is not None: vis[name].set_transform(transform) def rgb2hex(rgb: Tuple[int, int, int]) -> str: """ Convert RGB color values to hexadecimal string. Args: rgb (Tuple[int, int, int]): RGB color values (0-255) Returns: str: Hexadecimal color string (format: "0xRRGGBB") """ return "0x%02x%02x%02x" % (rgb) def create_visualizer(clear: bool = True) -> meshcat.Visualizer: """ Create a meshcat visualizer instance. Args: clear (bool): If True, clear the visualizer scene upon creation first Returns: meshcat.Visualizer: Initialized meshcat visualizer """ print( "Waiting for meshcat server... have you started a server? Run `meshcat-server` to start a server" ) vis = meshcat.Visualizer(zmq_url="tcp://127.0.0.1:6000") if clear: vis.delete() return vis def visualize_pointcloud( vis: meshcat.Visualizer, name: str, pc: np.ndarray, color: Optional[Union[List[int], np.ndarray]] = None, transform: Optional[np.ndarray] = None, **kwargs: Any ) -> None: """ Args: vis: meshcat visualizer object name: str pc: Nx3 or HxWx3 color: (optional) same shape as pc[0 - 255] scale or just rgb tuple transform: (optional) 4x4 homogeneous transform """ if vis is None: return if pc.ndim == 3: pc = pc.reshape(-1, pc.shape[-1]) if color is not None: if isinstance(color, list): color = np.array(color) color = np.array(color) # Resize the color np array if needed. if color.ndim == 3: color = color.reshape(-1, color.shape[-1]) if color.ndim == 1: color = np.ones_like(pc) * np.array(color) # Divide it by 255 to make sure the range is between 0 and 1, color = color.astype(np.float32) / 255 else: color = np.ones_like(pc) vis[name].set_object( meshcat.geometry.PointCloud(position=pc.T, color=color.T, **kwargs) ) if transform is not None: vis[name].set_transform(transform) def load_visualization_gripper_points(gripper_name: str = "franka") -> List[np.ndarray]: """ Load control points for gripper visualization. Args: gripper_name (str): Name of the gripper to visualize Returns: List[np.ndarray]: List of control point arrays, each of shape [4, N] where N is the number of points for that segment """ ctrl_points = [] for ctrl_pts in get_gripper_visualization_control_points(gripper_name): ctrl_pts = np.array(ctrl_pts, dtype=np.float32) ctrl_pts = np.hstack([ctrl_pts, np.ones([len(ctrl_pts),1])]) ctrl_pts = ctrl_pts.T ctrl_points.append(ctrl_pts) return ctrl_points def visualize_grasp( vis: meshcat.Visualizer, name: str, transform: np.ndarray, color: List[int] = [255, 0, 0], gripper_name: str = "franka", **kwargs: Any ) -> None: """ Visualize a gripper grasp pose in meshcat. Args: vis (meshcat.Visualizer): Meshcat visualizer instance name (str): Name/path for the grasp in the visualizer scene transform (np.ndarray): 4x4 homogeneous transform matrix for the grasp pose color (List[int]): RGB color values [0-255] for the grasp visualization gripper_name (str): Name of the gripper to visualize **kwargs: Additional arguments passed to MeshBasicMaterial """ if vis is None: return grasp_vertices = load_visualization_gripper_points(gripper_name) for i, grasp_vertex in enumerate(grasp_vertices): vis[name + f"/{i}"].set_object( g.Line( g.PointsGeometry(grasp_vertex), g.MeshBasicMaterial(color=rgb2hex(tuple(color)), **kwargs), ) ) vis[name].set_transform(transform.astype(np.float64))