panda3d_viewer

A simple 3D geometry viewer based on Panda3D game engine.

Install

Using pip

pip install panda3d_viewer

From source code

git clone https://github.com/ikalevatykh/panda3d_viewer.git
cd panda3d_viewer
python setup.py install

Examples

A simple scene in a GUI window

from panda3d_viewer import Viewer, ViewerConfig

config = ViewerConfig()
config.set_window_size(320, 240)
config.enable_antialiasing(True, multisamples=4)

with Viewer(window_type='onscreen', window_title='example', config=config) as viewer:

    viewer.append_group('root')
    viewer.append_box('root', 'box_node', size=(1, 1, 1))
    viewer.append_sphere('root', 'sphere_node', radius=0.5)

    viewer.set_material('root', 'box_node', color_rgba=(0.7, 0.1, 0.1, 1))
    viewer.set_material('root', 'sphere_node', color_rgba=(0.1, 0.7, 0.1, 1))

    viewer.move_nodes('root', {
        'box_node': ((0, 0, 0.5), (1, 0, 0, 0)),
        'sphere_node': ((0, 0, 1.5), (1, 0, 0, 0))})

    viewer.reset_camera(pos=(4, 4, 2), look_at=(0, 0, 1))
    viewer.save_screenshot(filename='box_and_sphere.png')

Render an animation offscreen

from math import cos, sin, pi
import imageio # install imageio: pip install imageio

from panda3d_viewer import Viewer, ViewerConfig

config = ViewerConfig()
config.set_window_size(320, 240)
config.enable_antialiasing(True, multisamples=4)
config.enable_shadow(True)
config.show_axes(False)
config.show_grid(False)
config.show_floor(True)

viewer = Viewer(window_type='offscreen', config=config)

viewer.append_group('root')
viewer.append_sphere('root', 'sphere_node', radius=0.5)
viewer.set_material('root', 'sphere_node', color_rgba=(0.1, 0.7, 0.1, 1))

with imageio.get_writer('sphere_anim.gif', mode='I') as writer:
    for i in range(50):
        angle = 2 * pi * i / 50
        x = 4 * cos(angle)
        y = 4 * sin(angle)
        z = 0.5 + 0.5 * abs(sin(angle))

        viewer.move_nodes('root', {'sphere_node': ((0, 0, z), (1, 0, 0, 0))})
        viewer.reset_camera(pos=(x, y, 2), look_at=(0, 0, 1))

        image_rgb = viewer.get_screenshot(requested_format='RGB')
        writer.append_data(image_rgb)

Render a point cloud

import numpy as np
import time

from panda3d_viewer import Viewer, ViewerConfig

with Viewer(show_grid=False) as viewer:
    viewer.reset_camera((10, 10, 15), look_at=(0, 0, 0))
    viewer.append_group('root')
    viewer.append_cloud('root', 'cloud', thickness=4)

    while True:
        vertices = np.random.randn(300000, 3).astype(np.float32)
        colors = np.ones((300000, 4), np.float32)
        colors[:, :3] = np.clip(np.abs(vertices), 0, 3) / 3
        viewer.set_cloud_data('root', 'cloud', vertices, colors)
        time.sleep(0.03)

Robotic examples

Using with Pinocchio

Pinocchio is a library for rigid multi-body dynamics computation. To see how to use this package with Pinocchio see example 1, example 2.

Visualize the point cloud from a RealSense camera

import numpy as np
import pyrealsense2 as rs
from panda3d_viewer import Viewer, ViewerConfig

config = rs.config()
config.enable_stream(rs.stream.depth, 640, 480, rs.format.z16, 30)
config.enable_stream(rs.stream.color, 640, 480, rs.format.bgr8, 30)

pipeline = rs.pipeline()
pipeline.start(config)
pc = rs.pointcloud()

camera_frame = (0, 0, 0.2), (0.7071, -0.7071, 0, 0)

with Viewer(window_title='RealSense') as viewer:
    viewer.append_group('root', scale=2)
    viewer.append_cloud('root', 'camera', thickness=4, frame=camera_frame)

    while True:
        frames = pipeline.wait_for_frames()
        color = frames.get_color_frame()
        depth = frames.get_depth_frame()
        if color and depth:
            pc.map_to(color)
            points = pc.calculate(depth)
            vertices = np.asarray(points.get_vertices())
            texture_coords = np.asanyarray(points.get_texture_coordinates())
            texture_image = np.asanyarray(color.get_data())

            viewer.set_cloud_data(
                'root', 'camera',
                vertices=vertices,
                texture_coords=texture_coords,
                texture_image=texture_image)

API

Viewer

This package contains Viewer, a thin wrapper on top of Panda3D ShowBase, an application framework responsible for opening a graphical display, setting up input devices and creating the scene graph.

Viewer constructor takes window_type parameter wich should be one of 'onscreen', 'offscreen'. When selected 'onscreen' the viewer open a GUI window. When selected 'offscreen' the viewer render to an offscreen buffer.

Optional config parameter allows manage the viewer appearance. Configuration provided by ViewerConfig class, which contains methods:

• set_window_size set window size (default: 800x600)
• set_window_fixed disable window resizing (default: on)
• enable_antialiasing turn antialiasing on or off and specify number of MSAA multisamples: 2,4,8,16 (default: off)
• enable_lights turn lighting on or off (default: on)
• enable_shadow turn shadows rendering on or off (default: off)
• enable_hdr turn HDR effect on or off (default: off)
• enable_fog turn fog rendering on or off (default: off)
• show_axes turn the axes rendering on or off (default: on)
• show_grid turn the grid rendering on or off (default: on)
• show_floor turn the floor plane rendering on or off (default: off)

To stop the viewer use stop method. Use join method to wait until a user close the window.

Managing 3D scene

All scene geometries organized in named groups. Each group contains arbitrary number of nodes. To manage the groups use append_group and remove_group. To hide or show all geometries inside a group use show_group.

To append a mesh node to a group use append_mesh, to append a primitive geometry node use append_capsule, append_cylinder, append_box, append_plane, append_sphere. To modify material of a node use set_material.

To specify nodes position in the space use move_nodes function. It takes a dictionary with node_name - position, quaternion pairs, so you can specify the position of all/any nodes in a group simultaneously.

Render to file or memory buffer

To capture an image and save it on the disk use save_screenshot. Specify path to the image file with extention in a filename parameter. If the filename is ommited it will be generated automatically based on the current date time.

To capture an image to a memory buffer use get_screenshot. Specify the color channels order in requested_format parameter. Default format is BGRA, allow any combinations of R,G,B,A channels. The function returns an image as a numpy array.

Scene appearance

To move the camera use reset_camera method which takes the desired camera position and target point.

Viewer provide several methods to manage visual appearance:

• set_background_color change background color
• enable_lights turn lighting on or off
• enable_shadow turn shadows rendering on or off
• enable_hdr turn HDR effect on or off
• enable_fog turn fog rendering on or off
• show_axes turn the axes rendering on or off
• show_grid turn the grid rendering on or off
• show_floor turn the floor plane rendering on or off

Window control

Keyboard shortcuts:

• Show help: F1, h
• Quit window: Escape, q
• Screenshot: Space
• Toggle axes: a
• Toggle HDR: d
• Toggle grid: g
• Toggle fps meter: f
• Toggle lighting: l
• Toggle fog: o
• Toggle plane: p
• Reset camera: r
• Toggle shadows: s
• Toggle texture: t
• Toggle wireframe: w

Mouse control:

• Move: LMB
• Scale: RMB, Ctrl+LMB
• Rotate: LMB+RMB, Alt+LMB
• Tilt: Alt+Ctrl+LMB

License

panda3d_viewer is licensed under the MIT License - see the LICENSE file for details