Ruler and scaling

[jules-l-jimmy]

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• I added a very descriptive title here.
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Sample Code What is the problem, question, or error?

Write a short description telling me what you are doing, what you expect to happen, and what is currently happening.

x_ratio = 0.03
offset = 0.01

p = pv.Plotter(off_screen=True,notebook=False)
pointa = [0.0, 0.0, 0.0]
pointb = [15.0, 0.0, 0.0]
pointc = [15.0, 0.1, 0.0]
rec = pv.Rectangle([pointa, pointb, pointc])
p.add_mesh(rec)
p.add_ruler(
    pointa=[rec.bounds[0]*x_ratio - offset, rec.bounds[3], 0.0],
    pointb=[rec.bounds[0]*x_ratio - offset, rec.bounds[4], 0.0],
    flip_range=True,
    title="Y",
)
p.add_ruler(
    pointa=[rec.bounds[0]*x_ratio, rec.bounds[4] - offset, 0.0],
    pointb=[rec.bounds[1]*x_ratio, rec.bounds[4] - offset, 0.0],
    title=f"X (*{x_ratio})"
)
p.set_scale(xscale=x_ratio)
p.view_xy()
p.show(screenshot="example.png")

Description

Hi,

I have a mesh with a strong aspect ratio. x = [0,15], y = [0;0,1]

I can scale down the mesh, DataSet.scale(x_ratio=0.03) or using Plotter.set_scale(xscale=0.03)

However when I add the ruler to the plotter with : plotter.add_ruler, I cannot get the original value on ticks.

Is it possible to get a scaled plotter with the ruler labels values of the original mesh ?

As you can see on this picture, my x ruler goes from 0 to 0.5 instead of 0 to 15.

System Information

--------------------------------------------------------------------------------

                  OS : Windows
              CPU(s) : 12
             Machine : AMD64
        Architecture : 64bit
                 RAM : 15.6 GiB
         Environment : Python
          GPU Vendor : Intel
        GPU Renderer : Intel(R) Iris(R) Xe Graphics
         GPU Version : 4.5.0 - Build 31.0.101.4953
    MathText Support : False

  Python 3.10.0 (tags/v3.10.0:b494f59, Oct  4 2021, 19:00:18) [MSC v.1929 64
  bit (AMD64)]

             pyvista : 0.43.5
                 vtk : 9.3.0
               numpy : 1.26.3
          matplotlib : 3.8.2
              scooby : 0.9.2
               pooch : 1.8.0
              pillow : 10.2.0
             imageio : 2.34.0
               PyQt5 : 5.15.10
             IPython : 8.20.0
            colorcet : 3.1.0
             cmocean : 4.0.3
          ipywidgets : 8.1.2
                tqdm : 4.66.1
              meshio : 5.3.5
          jupyterlab : 4.0.11
               trame : 3.6.0
        trame_client : 3.0.2
        trame_server : 3.0.0
           trame_vtk : 2.8.6
       trame_vuetify : 2.4.3
jupyter_server_proxy : 4.1.2
        nest_asyncio : 1.6.0
--------------------------------------------------------------------------------

Screenshots

[darikg]

It looks like add_ruler sets the range of the ruler to the distance between pointa and pointb. Here's a quick kludge that I think does what you're looking for

ruler = p.add_ruler(...)
a, b = ruler.GetRange()  # Either (0, distance) or (distance, 0)
ruler.SetRange(a / x_ratio, b / x_ratio)

[jules-l-jimmy]

Thank you, it works perfectly :)

[MatthewFlamm]

This would be a good addition to add_ruler input args.

[tkoyama010]

Thanks for the discussion. I opened #6096.