[Bf-committers] Cursor to center of mass

[Sergej Reich]

Actually, subdivide creates n-gons in most cases (unless you use it on edge rings or the whole mesh), so it's likely to be the problem.

Also here is a quick patch that adds a "Cursor to Center of Mass" option:
http://www.pasteall.org/37435/diff

Am Mi, 21. Nov, 2012 um 11:20 ,Jason Wilkins <jason.a.wilkins at gmail.com> schrieb:
Well, the calculation is used first to map the origin of the object 
and this discussion was just how to extend that to moving the cursor. 

As for it being because of n-gons, I do not think my model contained 
n-gons. What I did was call the subdivide operator 4 times on one end 
of the model, which created a bunch of new quads. Do quads count as 
n-gons in this case? 

I'll see if I can duplicate it and provide a .blend that narrows this 
down if there is a problem. 

On Wed, Nov 21, 2012 at 1:08 PM, patrick boelens wrote: 
> 
> Oops, I forgot this was about the cursor snapping and had something else in mind... My apologies. =) 
> 
>> From: p_boelens at msn.com 
>> To: bf-committers at blender.org 
>> Date: Wed, 21 Nov 2012 20:07:04 +0100 
>> Subject: Re: [Bf-committers] Cursor to center of mass 
>> 
>> 
>> I can sort of see the reasoning behind that, but I would also argue accuracy can be very important. Maybe it'd be worth it to make a "high quality" operator bool in the same vein as the "high quality normals" in the Solidify modifier? 
>> 
>> -Patrick 
>> 
>> > Date: Wed, 21 Nov 2012 17:36:19 +0001 
>> > From: sergej.reich at googlemail.com 
>> > To: bf-committers at blender.org 
>> > CC: bf-committers at blender.org 
>> > Subject: Re: [Bf-committers] Cursor to center of mass 
>> > 
>> > Hey Jason, 
>> > 
>> > currently there is a problem with n-gons when chalculating the center of mass. 
>> > The issue is that we don't have a good way of calculating centroids for n-gons and just use the vertex average, so the calculated origin will drift a little when your polygons have many vertices. 
>> > I'd prefer to just tirangulate the model and use the triangle centroids but after a discussion with Campbell we decided it's not worth allocating a bunch of faces just to get a litte more accuracy. 
>> > 
>> > Regards, Sergej. 
>> > 
>> > Am Di, 20. Nov, 2012 um 12:12 ,Jason Wilkins schrieb: 
>> > Brecht, I figured that was what it did after testing it some, but 
>> > since subdividing a face caused the center to move slightly I had my 
>> > doubts. If it was vertexes I expected a really large move (since 
>> > there were 100 times as many vertexes in my subdivided face than the 
>> > rest of the model), but using faces or tets it should not move at all. 
>> > Did I find a bug? 
>> > 
>> > On Mon, Nov 19, 2012 at 5:05 PM, "Martin Bürbaum" 
>> > wrote: 
>> > > Just FYI - I did something similar ("Snap Cursor to Centroid") as a script a while back. 
>> > > 
>> > > http://projects.blender.org/tracker/index.php?func=detail&aid=30299&group_id=153&atid=467 
>> > > 
>> > > Cheers, 
>> > > Martin 
>> > > 
>> > > -------- Original-Nachricht -------- 
>> > >> Datum: Mon, 19 Nov 2012 19:00:23 -0300 
>> > >> Von: Juan Pablo Bouza 
>> > >> An: bf-committers at blender.org 
>> > >> Betreff: [Bf-committers] Cursor to center of mass 
>> > > 
>> > >> 
>> > >> Hi! The addition of the "center of mass" option for object origins is 
>> > >> really cool! 
>> > >> 
>> > >> Now, there are many times in rigging when you need the center of the 
>> > >> object to be at 0 0 0, specially for exporting meshes. So, in these 
>> > >> cases, the "origin to center of mass" option would not be used. 
>> > >> Nevertheless, the center of mass options would be really usefull for 
>> > >> placing objects such as bones... 
>> > >> 
>> > >> So, I propose to add the center of mass option also in the Cursor 
>> > >> snapping menu (shif+S). That would be "cursor to center of mass". 
>> > >> 
>> > >> Cheers! 
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