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Topic: Smooth Groups  (Read 9341 times)

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  • Polygon
February 27, 2014, 02:30:49 pm
Hi IStonia,

If you could find time, would it be possible for:-

A new P_Function:- P_AutoSmooth_{Angle}

A "Smooth All" command for binding to an hotkey/user button.

Both could save time when dealing with smooth groups.

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  • Spline
February 27, 2014, 03:49:08 pm
It was wished before but couldn't one additionally introduce a setting which doesn't assign different smoothing values to entities ever? I never need Low res geometry and simply have no requirement to fake different edge weights through means of shading. Couldn't one opt to turn everything connected with Smoothing Groups off altogether, in all areas of the program or is that function so deeply nested in the code that this is unrealistic?

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  • Polygon
February 27, 2014, 04:51:47 pm
Couldn't one opt to turn everything connected with Smoothing Groups off altogether, in all areas of the program or is that function so deeply nested in the code that this is unrealistic?

From what I see of the behavior in Nvil, is that some geometry is given a smooth group, and other geometry is left unassigned.
I did think about asking if possible for all geometry to be assign to the same (a default) smooth group, but am not sure as to how much work that would entail. So thought to ask for the added commands, so a single hotkey (be it from a composite) could be used for either placing all geometry on an object into a single smooth group(as you are looking for), and/or the ability to quickly remove all smooth_groups and replaced with custom.

« Last Edit: February 27, 2014, 04:56:09 pm by steve »

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  • Spline
February 27, 2014, 05:27:47 pm
Thanks for your answer Steve! I see that your requests are quite pragmatic but and try to deal with what's given. What however, if for certain user-groups a given, automatically assigned property is of no value whatsoever but instead merely is a source of errors? Should one then really pester the user with turning off what he never wanted turned on in the first place?

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  • Polygon
February 28, 2014, 02:36:07 am
think you just thinking of it wrong.

Smoothing groups is really just the method max uses to deal with split normals, internally nvil prolly handles the data more similar to how Maya does, which is by using hard and soft edges.

If you wanted to simply smooth a whole mesh, just select all edges, and run "Soften", it;s in the geometry menu when edges are selected, than you can harden selected edges by going to "Harden Selected" which is in the same menue.

i got these both on marking menus

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  • Triangle
February 28, 2014, 04:33:22 am
FYI, here's a very informative video on smoothing splits and vertex count, and what it means for uv mapping, especially for game assets:
http://youtu.be/ciXTyOOnBZQ

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  • Polygon
February 28, 2014, 07:56:00 am
think you just thinking of it wrong.

Smoothing groups is really just the method max uses to deal with split normals, internally nvil prolly handles the data more similar to how Maya does, which is by using hard and soft edges.
You should read the help file and check how Nvil actually works with smooth groups.
From the help file:-
Quote
Smooth Groups
"Polygons can be grouped into smooth groups by either assigning smooth group flags on polygons or by vertex/edge based smooth group control operations which is smooth group flag independent.

This tool uses smooth group flag method."

So no, it is not like Maya.
If I remember correctly, Maya does not work with smooth groups, so those will be ignored on import.

Quote
If you wanted to simply smooth a whole mesh, just select all edges, and run "Soften", it;s in the geometry menu when edges are selected, than you can harden selected edges by going to "Harden Selected" which is in the same menue.
You will not remove smooth groups.

Create a box primitive, select all edges and "Soften" edges. In polygon mode, open "Smooth Groups" and check. You will see the smooth groups are still there.
From my own point of view, having both Smooth groups and Hard_edges leads to much confusion as to the actual implementation. If it really needs to have both smooth groups and Hard_edges, then it should deal with them better, and not be automatically adding smooth groups or hard_edges at any time at all, and let the user add those when actually wanted/needed.

I have just been looking at Nvil export- .dae
That appears to be either corrupting the exported smooth groups, or corrupting the smooth groups on import. (save box as .dae with export smooth groups enabled, import that file back into Nvil, and smooth groups corrupted/incorrect)




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  • Spline
February 28, 2014, 08:03:14 am
Thanks Passerby and Vaquero. I'm not saying that having the option to assign individual shading properties for edges and vertices sucks. What I dislike is that Nvil works under the assumption that hard/smooth edges/smoothing groops concept is useful for all its users, at least in one context or another. Therefore an Nvil user inevitably needs to start keeping in mind that the program does something to the geometry on needs to deal with, latest before exporting to other apps: Otherwise one might see the phenomen that Nvil geo subdivides without smoothing elsewhere.

Again: I don't need manipulation of smoothing angles ever, what this handplane video shows has no relevance for my work. I use Nvil for conceptual modelling in Product Design, there's no point in dealing with Low Poly assets and classical polygon modelling (without SubD) here.
Therefore I rather compare to Silo - here one got left alone altogether with this smoothing trickery. But again: I of course don't ask to remove these features which are so useful for you guys, I only wished for a program preference which gives users the choice to turn the use of these industry specific shading helpers off entirely.

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  • Polygon
February 28, 2014, 08:05:19 am
Should one then really pester the user with turning off what he never wanted turned on in the first place?

No.
I do not want or use smooth_groups or hard_edges, and in Nvil they are a complete pain to have to keep removing what Nvil keeps automatically adding.
Another user posted 2 or 3 times about Nvil keep creating hard_edges and wanted it to stop, but nothing was done(at least nothing noticeable). I have not seen that user on forum since then.

« Last Edit: February 28, 2014, 08:11:14 am by steve »

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  • Spline
February 28, 2014, 09:23:32 am
Should one then really pester the user with turning off what he never wanted turned on in the first place?

No.
I do not want or use smooth_groups or hard_edges, and in Nvil they are a complete pain to have to keep removing what Nvil keeps automatically adding.
Another user posted 2 or 3 times about Nvil keep creating hard_edges and wanted it to stop, but nothing was done(at least nothing noticeable). I have not seen that user on forum since then.

Here, here.  Similar to Polyxo, I work in product design, and my work is for rapid prototype.  So smooth groups and any other visual window dressing for low res models is more hindrance than help to me, because the *actual underlying geometry*, whether that means split normals or what-have-you, is going to become visible and facetted on the printed model unless I increase the actual geometry, usually through subdivision.  To that end - I rarely have need or reason to maintain low poly counts at all (aside from viewport performance).  So it's important for me to always be able to see the geometry in its most literal way, warts and all.  Presently, I do find it a pain to constantly remove auto-assigned smoothing groups, plus I don't always know what adds them and what doesn't.  I understand why smoothing groups are important to some users, but I personally wish I could globally toggle them off and add them manually if I feel like it.  Same with hard edges.

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  • Polygon
February 28, 2014, 11:20:36 am
I think smoothing groups should be dumped and removed completely, than have hard edges become the only system for managing spilt normals. Than in the application preferences there should be a setting to set at what angle a edge automatically becomes hard.

So in the case of people that don't want spilt normals set it to 180.

Also iirc when you subdivided it uses avaraged normals anyways, so normal splits won't effect your subdivided result.

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  • Spline
February 28, 2014, 11:52:24 am
Also iirc when you subdivided it uses avaraged normals anyways, so normal splits won't effect your subdivided result.
This may be true for subdividing inside Nvil. But if you export a low res cage out to subdivide it inside other applications one may run into problems - see here

I wonder how Maya handles this mattter. It has no smoothing groups but how does it deal with hard/soft edges? Are these automatically added by Maya? I seriously doubt this. What I would expect is vanilla smoothing for every item added to the scene. People with low res, game specific interests can then take manual steps to introduce additional, non standard shading properties. If the user does nothing, common smoothing attributes are used for everything.

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  • Polygon
February 28, 2014, 01:04:56 pm
polyxo your mis understanding a key concept, smoothing groups are simply a way of managing vertex normal splits, a method for the most part is only used by 3ds max and a few others, maya uses edges that are tagged soft or hard.

Also if the right options are set maya also just uses averaged normals not split normals when meshs are subdivided.

Than Maya has a global var for normal angle where you can set a angle between 1 and 180 degrees for what gets automatically set to hard. If you explicity set something soft or hard it isnt effected by this angle.

But say i don't want there to ever be split normals in maya, i would simply just set this to 180 degrees, and never tag anything as hard.

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  • Spline
February 28, 2014, 01:29:36 pm
I'm perfectly sure that I miss a lot of the details of what one can do with Normal-editing on low res geometry :) That said - you basically agreed that Maya doesn't mess with your mesh-smoothing until the user explicitly assigns overrides of global properties. And that's what I think made sense in Nvil too.

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  • Polygon
February 28, 2014, 01:43:34 pm
ya the preferences just need a user setable angle for what gets turned into a hard edge.