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I'm trying to code a function that gets the base dimensions of an object that has multiple modifiers applied.

Sure, I can turn all the modifiers off, get the dimensions and then re-enable everything, but I'm wondering if anyone knows a different solution.

I tried with the bounding box but that is also affected by the modifiers. I also tried using the mesh data object.data.dimensions but meshes don't seem to have the "dimensions" attribute.

Any ideas, elegant or otherwise?

Armored Wolf
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1 Answers1

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Look at the mesh coordinates.

The unmodified dimensions of the mesh can be obtained from the mesh.

import bpy
import numpy as np

ob = bpy.context.object
me = ob.data


coords = np.empty(3 * len(me.vertices))
me.vertices.foreach_get("co", coords)
x, y, z = coords.reshape((-1, 3)).T


mesh_dim = (
        x.max() - x.min(),
        y.max() - y.min(),
        z.max() - z.min()
        )


print(mesh_dim)

Could use this to give a mesh a dimensions property

import bpy
import numpy as np
from bpy.props import FloatVectorProperty

def get_mesh_dims(self):
    coords = np.empty(3 * len(self.vertices))
    self.vertices.foreach_get("co", coords)


x, y, z = coords.reshape((-1, 3)).T

return (
        x.max() - x.min(),
        y.max() - y.min(),
        z.max() - z.min()
        )




bpy.types.Mesh.dimensions = FloatVectorProperty(
        name="Mesh Dimensions",
        get=get_mesh_dims,
        subtype='XYZ',
        unit='LENGTH',
        )

python console code, default cube, arrayed subsurfed spun and hung.

>>> C.object.data.dimensions
Vector((2.0, 2.0, 2.0))
batFINGER
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  • Thanks for taking the time to explain with so much detail. This will help me in so many ways. I didn’t know you could create custom properties like that. Bless you! – Armored Wolf Feb 24 '21 at 08:08
  • NP! Thanks, the feedback is appreciated. Scratch that re texture size, what was I thinking uses normalized size. – batFINGER Feb 24 '21 at 08:19