3D semantics

[pitibonom]

Hi all

Old blender user, i’m quite new here
I recently switched from 2.79 to 2.9 and noticed some 3D view inconsistencies.

The 1st one is very simple and is about the 3D view option: ‘flat’

The word is confusing as it don’t show the 3D view in flat shading but in unlit color shading.

I’ll come back later with the 3D view modes inconsistencies ( seen by some ppl as a lip ahead ).

Happy blending !

EDIT: i don’t know if there are blender devs here but i got to mention that i’m a former dev ( 35 years in 3D asm, C,C++,C# ) and that it will/would be a pleasure to exchange with them about this great tool called blender

[JuanGea]

This is full of all the Dev team

I don’t understand what you mean, for me “flat” it’s what is represented in the viewport, keep in mind that the option it’s under the “lighting” section, unlit shading without any kind of shadows or mesh volume “feeling” is what I would expect here:

Of course you can enable the viewport shadows to have some kind of volume feeling:

Or configure it to have a more “cel shading” feeling:

But I think that the term flat is accurate here

What do you have in mind for “flat”?

[Debuk]

Flat shading a common term and that’s what he’s referring to.

Shading | Flat shading

And yes whats called flat here is not classic flat shading.

@pitibonom: What you are referring to is placed in the context menu under Shade smooth and Shade Flat

[JuanGea]

Yep, but as I said, this is under the lighting section, so it’s inside the shading options, “flat lighting”, not flat shading

BTW I’m all in about having a “flat shading” option for the whole viewport, not just the per-object/mesh property

[Debuk]

Yeah i know that you did, but thats what he meant. Thats all.

[pitibonom]

Then this is definetely the place i like to be

Hmmmm maybe i’m mistaken by my lighting methods jargon and i’m not sure they are the ones used in 3D art. But i guess 3D devs know about it as it’s used in the main systems 3D APIs ( OpenGl, Mesa, DX etc… )

Please lemme just introduce you with what i mean. The best way to do it is simply a WP link: Shading - Wikipedia

Here are shown the 3 most fundamental ( and btw the fastest ones ) methods of displaying faces of an object in a colored method.
As you can see the flat method simply draw each face with the same color. Each face is different from others simply because the color is calculated in function of a light source position and the applied to the face beeing drawn.
This is far from accurate but quite convenient when you want very fast rendering of million faces.

In your pics,:

• The 1st one is what i would call ‘unlit colored’ instead of flat. IMHO this mode is quite useless as your eye has no information about volumes beeing seen.
• The 2nd pic is as i can imagine some Gouraud or Phong shading. Each pixel light is calculated by interpolating normals over the face surface.
• The 3rp pic is what i would call Toon shading but i know this one very few as i didn’t use it often. It’s some triggered Phong shading.

EDIT: aww ppl posted before me. I got to read

[pitibonom]

Wow okay

It appears that i’m mistaken with my old uses
It’s because it is in the shading option menu
I didn’t even know flat lighting existed and now i wonder what is the use of it
But that is another topic…

Aside this, i feel this shading menu inconsistent towards the object properties>viewport display and different from what was in 2.79.

For faster drawing ( and loading ) i used the display as>textured only for the objects of interrest. Since 2.8, the objects in viewport are all texture, no matter the display as option is.
This works if you choose wireframe, but sold and texture do the same visual result.

[Debuk]

Flat Lighting is not really a good choice as a term
(as you asked it can be eg handy to give every separate object a different color)
And yes in fact unlit is the much more common term for that. I think it was rather a pragmatic decision.

@pitibonom

Here are shown the 3 most fundamental ( and btw the fastest ones ) methods of displaying faces of an object in a colored method.

You are referring to classic lighting /reflectance models. And yes there are much more for that like cook torrance, oren nayar and alike.

But whats put in that Lighting section are rather some useful basic options for scene “lighting” while modeling, like matcaps or premade light setups.

[JuanGea]

@pitibonom

I didn’t even know flat lighting existed and now i wonder what is the use of it

Just as a quick example, a lot of animes are done in 3D (some with Blender, some with other packages), and they use some kind of flat lighting (cell shading).

Here you have a good example, a lighting test from an artist:

ruki (rukikuri)

Flat shading without shadows is also very useful for when you have to dig into a super big scene with a lot of objects and you want to find some specific object, keep in mind that you can mix it with textures or random color, very useful.
Also it’s useful to paint textures without having to deal with the lighting effects, not shadows, or self shadowing or darkening, etc… it’s a useful mode.

Unlit could also be used, but I think since it’s inside lighting, unlit can be understood a non-lit at all or absence of light, unlit, as we can understand it, refers to the shader itself and not to the actual scene lighting, so I still think Flat is a good choice for the lighting section

[pitibonom]

Oh then call it Anime

Okay you got the argument and it makes sence though it can be confusing for some ppl like me for whom ‘flat’ is something else.

I think this quite simple shading menu is far more complex than the one in 2.79 and i just got to get used to it
And also find my proper setup for my workflow.
I got many questions about it but i first have to RTFM and dig in it on some more general forums than bugging devs about it here

Have a very nice end of day and…

Happy blending !

[JuanGea]

@pitibonom

Oh then call it Anime

Nope, that’s just one example of it’s usage, but it’s used in many other areas, like engineering or other types of animation

@pitibonom

I think this quite simple shading menu is far more complex than the one in 2.79 and i just got to get used to it

Yes, the change is quite big, in many areas, specially if you came directly from 2.79 to 2.90, that’s even bigger than from 2.79 to 2.80

Likewise

[Debuk]

The usage of lighting and shading is often sort of unsharp, but in this context lighting typically refers to the lighting model used (or to the light setup of a scene, and both topics are a bit mixed up in this menu)

On the other hand there is the shading and btw. cell shading can be used with different lighting models beneath and the brightness of a pixel is just not the brightness calculated at that point.
Cellshading is not flat lit or unlit, its shaded with quantized values.

Unlit as a common term describes that for the shading no light information is calculated at all and every point in the scene transports the same amount of light in eye direction,

So in short its not lit (unlit) but shaded.

And even if the amount of light could be seen as “flat” its not common to say that.
So I’d vote for the more common term unlit.

Anyways,have a nice evening guys.

[JuanGea]

@Debuk

On the other hand there is the shading and btw. cell shading can be used with different lighting models beneath and the brightness of a pixel is just not the brightness calculated at that point.
Cellshading is not flat lit or unlit, its shaded with quantized values.

Of course, it was just an example

@Debuk

So in short its not lit (unlit) but shaded.

or un-shaded, maybe this term explains a bit more than unlit.

In shading programming and real time engines Unlit refers to a shader that will not be affected by light, but it’s not mandatory for that shader to not have shadows, the shadows could be computed inside the shader, and it’s not mandatory to nto show volume, it’s just that it’s not being affected by light, so I don’t agree with that Unlit is the common term, I see Unlit as the common term for that kind of shaders.

Flat on the other hand shows a flat value all over the place, so there is no change in “value” , no shadows, no highlights, that’s why there is no volume at all, and that’s why “Flat” is also a good term.

However a middle ground could be un-shaded, but that may be a bit weird, because it’s not so common.

Unlit is common in real time engines for the shaders, “Flat” is common from an artistic point of view, I think in the end it’s a matter of opinions more than reasoning.

For example you think that things are e bit mixed in that menu because it’s the “Viewport Shading” shading menu, I think the title is accurate and the options inside are fine also, because they are correctly separated in sections that are self-explanatory, Lighting, Color, Background and Options, and all that refers to how the shading is going to be applied to the viewport.

Keep in mind that the menu is called that way no matter the mode it’s in, so it’s not just for Solid, but also for Material Preview, Renderd, and Wireframe, and each of them shows their own options for how the viewport will be “shaded”.

We could say that a more accurate term would be “Viewport Rendering Options”, but in that case it will be more confusing because the common term “Viewport Rendering” is used to enable the final render engine inside the Viewport as IPR, so personally I think that “Viewport Shading” and “Flat” are both accurate enough.

But as I said, we are talking about something so “fine” that I think it’s a matter of opinion