Difference between Rhino's VolumeCentroid vs Rhinocommon Centroid?

Rhino Developer
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1

When I compute AreaMassProperties on a brep, the Centroid seems to be different from Rhino’s VolumeCentroid command. Can anybody explain to me why that is or what the difference is?

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image1590×1251 54.3 KB

You can try with this C# script in scripteditor:

using System;
using Rhino;
using Rhino.Input.Custom;
using Rhino.Geometry;

var go = new GetObject();

go.Get();

var brep = go.Object(0).Brep();

var amp = AreaMassProperties.Compute(brep);

Rhino.RhinoDoc.ActiveDoc.Objects.AddPoint(amp.Centroid);

Using pythonscriptsyntax’ SurfaceVolumeCentroid seems to give the same result as the Rhino command.

231221 VolumeCentroid.3dm (69.0 KB)

2

For volume centroid, use VolumeMassProperties.

You are calculating the centroid as if your brep was hollow, made out of paper…

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3

Of course. So obvious when you point it out. :man_facepalming:

1 Like