Hi Plotlyers,

I am trying to export normals to vertexes of a 3d mesh created in opend3d in a format suitable to Mesh3d (i,j,k vectors).

I have a working mesh computer with the Poisson method from which I extract the vertexes coordinates and the normals to the vertexes

```
poisson_mesh, densities = o3d.geometry.TriangleMesh.create_from_point_cloud_poisson(pcd, depth=9, width=0, scale=4, linear_fit=False)
xgo=np.asarray(poisson_mesh.vertices).T[0]
ygo=np.asarray(poisson_mesh.vertices).T[1]
zgo=np.asarray(poisson_mesh.vertices).T[2]
tigo=np.asarray(poisson_mesh.vertex_normals).T[0]
tjgo=np.asarray(poisson_mesh.vertex_normals).T[1]
tkgo=np.asarray(poisson_mesh.vertex_normals).T[2]
```

upon plotting these into plotly there is just an empty plot:

```
fig4 = go.Figure(go.Mesh3d(x=xgo, y=ygo, z=zgo,
i=tigo, j=tjgo, k=tkgo,
intensity=dgo,
colorscale="Viridis",
colorbar_len=0.75,
flatshading=True,
lighting=dict(ambient=0.5,
diffuse=1,
fresnel=4,
specular=0.5,
roughness=0.05,
facenormalsepsilon=0,
vertexnormalsepsilon=0),
lightposition=dict(x=100,
y=100,
z=1000)))
fig4.update_layout(width=800, height=800)
fig4.show()
```

just the coordinates and perhaps the parameter alphahull=3.5 (without i,j,k) are giving the desired plot.

The shape of each x, y and z is n, as well as the shape of i, j and k, and according to the docs thatâ€™s ok. How can I check the condition `{i[m], j[m], k[m]}`

together represent face m (triangle m) in the mesh, where `i[m] = n`

points to the triplet `{x[n], y[n], z[n]}`

? Is this a convention across different libraries?

I tried to pass all the o3d through `trimesh`

:

```
tri_mesh_pois = trimesh.Trimesh(np.asarray(poisson_mesh.vertices), np.asarray(poisson_mesh.triangles),vertex_normals=np.asarray(poisson_mesh.vertex_normals))
ti=tri_mesh_pois.vertex_normals.T[0]
tj=tri_mesh_pois.vertex_normals.T[1]
tk=tri_mesh_pois.vertex_normals.T[2]
```

the shape is the same, the numbers are different (I think they have been automatically normalised), but using these new normals doesnÂ´t solve the problem: still no plot.

Any suggestion?