Flip Z axis for mesh plotting

[thoth291]

First of all - this is BRILLIANT project! Thank you so much for making it to work.

I do scientific visualization all the time - and tools like this really enablers for pushing science forward! Thank you!  

• K3D version: 2.16
• Python version: 3.10.12
• Operating System: CentOS Linux release 7.7.1908
• vtk-osmesa

Description

I'm plotting a custom mesh which is being generated by another engine. Everything plots well, except that my Z axis is going in opposite direction to what I want. It goes up - I need it to go down (visually) while my Z values go up.

What I get:

What I want:

What I Did

Essentially this code - except that I had my own data with verts and inds.

import k3d
import numpy as np

data = np.load('streamlines_data.npz')
plot = k3d.plot()
plot += k3d.mesh(data['vertices'], data['indices'],
                 opacity=0.25, wireframe=False, color=0x0002)
plot.display()

In other visualization tools I can simply set something like flip_z or z_flip - but can't figure out how to set it here.

Am I missing something obvious, or this is not possible to script in the code?

Would appreciate for your help! Thanks in Advance!

[etienne87]

just revert the data['vertices'] Z axis in python:

data['vertices'][:,z_axis] = max_z - data['vertices'][:,z_axis]
data['vertices'] = data['vertices'][::-1]   # needed otherwise k3d cancels effect of first line

[artur-trzesiok]

I agree with @etienne87 . I dive into topic in three.js but I found this: https://discourse.threejs.org/t/convert-from-one-coordinate-system-to-another/13240/42

Looks like there is no direct support in threejs to do that

[artur-trzesiok]

So at this moment I dont see any short way how to implement it to be consistent in all type of objects. As only threejs will add support for that we can re-open a issue