I'm using the amazing open3d Python libary to visualize some point Cloud. I already know the normal vectors of these points that I attribute directly as follows:
pcd = o3d.geometry.PointCloud()
pcd.points = o3d.utility.Vector3dVector(points)
pcd.normals = o3d.utility.Vector3dVector(normals)
I am also setting a visualizer in which I insert these points as follows:
app = gui.Application.instance
app.initialize()
vis = o3d.visualization.O3DVisualizer("Open3D - 3D Text", 1024, 768)
vis.show_settings = True
vis.add_geometry("my points", pcd)
with o3d.utility.VerbosityContextManager(o3d.utility.VerbosityLevel.Debug) as cm:
'''visualize'''
vis.reset_camera_to_default()
app.add_window(vis)
app.run()
Up to now, all of this has run as intended, however I am not able to set the visualizer in such a way that enables me to visualize the normal vectors. Apparently o3d.visualization.Visualizer() has this method get_render_option() that is said to "retrieve a RenderOption" object, and in this RenderOption object there is a point_show_normal property but I couldn't make my code (more complicated than the minimal example above) work with o3d.visualization.Visualizer(): I don't see how to use this o3d.visualization.Visualizer().get_render_option().point_show_normal.
Is there any way to show the normal vectors with with open3d.visualization.O3DVisualizer?
2 Answers
you need add two lines to your code, get the render and set point_show_normal to True:
opt = vis.get_render_option()
opt.point_show_normal = True
You can see in the documentation open3D tutorials and python examples
I hope it helps
I didn't find a solution so far, so I resorted to look at my normal vectors in another window, produced using the mayavi library rather than the open3D library. To do so, I used this simple code snippet:
from mayavi.mlab import *
P = [my list of 3D points]
N = [my list of normal vectors]
x = P[:, 0]
y = P[:, 1]
z = P[:, 2]
points3d(x, y, z, color=(0, 1, 0), scale_factor=0.5)
u = N[:, 0]
v = N[:, 1]
w = N[:, 2]
quiver3d(x, y, z, u, v, w)
show()
And it worked as intended. Ideally I would like to have the normal vectors displayed with the rest of the figure, but this responded to my immediate needs.
I consider this as a workaround rather than the definitive solution, so I put it here as an answer if someone else having the problem finds it useful. But my question still isn't solved.
