How to set and rotate an assembly around a local axis of my choosing

[BXL801]

Hi,

I'm loving vedo and am starting to go a little deeper. Currently i have an assembly with a pointcloud and a wirefram that connects the points.
When I use RotateZ X or Y it rotates as if the axis is aligned to the screen. I wish to set a different axis orientation i derrived from calculating the yaw pitch and roll. Could you tell me how I should approach this?

Thanks in advance,

Rob

[marcomusy]

Hi
You can directly rotate the assembly with

from vedo import *

pts = np.random.rand(20, 3) * 10
pc = Points(pts).c('blue').alpha(0.5).ps(8)

line = Line(pts).c('red')

asse1 = Assembly([pc, line, pc.labels("id")])
asse2 = asse1.clone().rotate_x(90).shift([12,0,0])

show(asse1, asse2, axes=1).close()

or, you mean you need to compute the 3 angles based on yaw pitch and roll?

[BXL801]

Dear Marco,

Thank you for your prompt response and the example.
To clarify my question: I have calculated yaw, pitch, and roll angles (or a corresponding rotation matrix) that describe the current orientation of my point cloud relative to a canonical frontal pose.
I would like the assembly's local axes to be aligned with this calculated pose, so that calls to assembly.RotateX(angle) (pitch), RotateY(angle) (yaw), and RotateZ(angle) (roll) rotate the entire assembly (point cloud + wireframe) relative to the object's own orientation—similar to local rotation in 3D modeling software—rather than the global or screen-aligned axes.
Currently, RotateX/Y/Z appear to use global axes, causing unintended gimbal effects when applying sequential rotations in arbitrary order.
Is there a recommended way to set or reorient the local rotation axes of an Assembly (or its children) to a custom orientation derived from yaw/pitch/roll?

Thank you for your assistance.

Best regards,

Rob

[marcomusy]

Hi Rob
what about something like this?

from vedo import *

pts = np.random.rand(20, 3) * 10
pc = Points(pts).c('blue').alpha(0.5).ps(8)

line = Line(pts).c('red')

asse1 = Assembly([pc, line, pc.labels("id")])
axes = Axes(asse1)

plt = Plotter()
plt.add(asse1, axes)

plt.camera.Roll(10)
plt.camera.Yaw(20)
plt.camera.Pitch(30)
plt.renderer.ResetCamera()
plt.camera.Zoom(0.8)

plt.render().interactive().close()