An In-Depth Guide to the Model Differences (with Pictures!)

[cami]

Update 6/2/16: Talked a bit about iris shapes.

Disclaimer: I know the update patch is coming out soon. I just thought I would jot down my thoughts in one concise place, seeing I have repeated this stuff in other threads. I also wanted to present some new information as well. Hopefully, this'll be something to look back on.

If you don't want to read, or want to have the gallery ready ahead of time, take a look at the image gallery here: RWBY Model Differences[imgur.com]

Contents

• 0. Introduction
  
• 1. Shading/Lighting
  
• 2. Eyes
  
• 3. Textures
  
• 4. Level of Detail
  
• 5. Other Modelling Differences
  
• 6. Conclusion

0. Introduction

A lot of people seem to dislike the new models, but they might not reason why besides exclaiming "They're not the old models!".
I want to go over a list of changes that explain what differences they actually made, how they compare to what other people do to cope with the challenges, and so on.

What do I know about models, lighting, and texturing? I've taken graduate level courses on computer graphics and global illumination. So I should probably know what I'm talking about. If I don't, let me know.

I have included some addenda for additional reading. They aren't required, but are interesting tidbits of information.

1. Shading/Lighting

In the current build of the game, the characters are lit by a global light (the sun),
and shadowed by other objects in the game space.
Being lit by a global light is also referred to as vertex-lit.

This differs from how the characters appear in the previous Combat Revision: The old shading program rendered the characters without any shadows. Without any discoloration from the global lighting, the old characters were unlit models.

Addendum 1A: Wait, isn't RWBY cel-shaded?
Cel-shading is the often cited term for the look that the RWBY show has.
While it is true that there are patches of single-colored shades on the models of the characters, the shading never differs as the character model animates in the scene.
e.g. Weiss's neck is always that level of shade, even if a light were to shine brightly on her neck.
Defining shades in the texture gives the artist more liberty to render the character correctly, rather than worrying about shading calculations disrupting the look of the show.

Addendum 1B: Does that mean real-time cel-shading is hard to get right?
Very much so. Arc System Works describes the difficulties in their GDC 2015 conference.
The entire video is very interesting if you're into cel-shading, but the part relevant to the conversation is here:
GuiltyGearXrd's Art Style: The X Factor Between 2D and 3D (Video)

Now, how do these differences hold up in game? If we change only the lighting, the differences are described by this picture:
Picture 1: Weiss - Vertex-Lit vs Unlit

While the model mostly looks correct using a vertex-lit shader, the face doesn't look quite right.
The problem is an anime character's face is shaped in a way that doesn't reflect light like a human's face does, so when it's realistically lit, it looks a bit like a doll's face.

How to remedy it:

• If they were to go forward with a shaded model, the developers might improve the situation by adjusting the normals (the angles that light hits the surface of a polygon) on the face so the face looks more even, and as a result, more anime-esque, as shown in Addendum 1B.
  
• Use an unlit shader, which they are probably going to do.

2. Eyes

Yes, the eyes look off. But why do they look off?
Review this picture:
Picture 2: Blake - Comparison of Face at Profile & at 45 Degrees[i.imgur.com]

Yikes. Blake's eyes are bulging out of their sockets in the Forever Fall model.
Sure, a human's eyes are spherical in nature, so wouldn't it make sense for a 3D model to have spherical eyes, too?

Well, if an anime character truly had eyeballs the size of their eyesockets, they wouldn't have much space in their cranium for a brain.

It turns out that translating anime to 3D is harder than it seems. The common limiting factor is modeling the eyes correctly so they look good at any angle. And decidedly, anime commonly breaks conventions of realism and accuracy in order to push the style better.

Addendum 2A: Isn't it the case that some anime use 3D models for characters?
Anime might use 3D models to save on production time for complex scenes. (Love Live!, Re:Zero)
Most often, you wouldn't want to see these models up close, because they end up being very uncanny and unpleasant to look at.

3D models suffer greatly from stiffness of animation, and while animation smearing and model deformation might help (Guilty Gear xxrd, RWBY, Overwatch), sometimes you really have to break the model to get it to look like anime.

A good example? This.

Addendum 2B: Are we ever going to get anime in real life, then?
Maybe not walking and talking, but we already do have representations of anime in 3D form: figures.
Figure of Momohime from Oboro Muramasa[s1.tsuki-board.net]

Most figures use a material called PVC, to get a soft, diffused light across the surface of the figure's face. This is called subsurface scattering.
The problem with subsurface scattering is that it is inefficient for real-time applications, such as games, to calculate on the fly. This means less frames per second.

Figures represent eyes with a nearly flat surface, and for most situations looks impressive.
Since figures do not have to move their eyes, we don't have to worry about modelling them for animation, but perhaps we do want to move the characters eyes in a game. The situation varies.

Addendum 2C: What's out there to make it easier for people to make 3D anime games?
Why not try a hybrid of 2D and 3D?
Live2D, the pioneers of animated 2D artwork, have delved into implementing their systems for integration into 3D models.
It's called Live2D Euclid. Take a look!
Live2D Euclid (Video)

So, what is the trick that makes the eyes in RWBY look like an anime's?

If you take a look at the wireframe on the Combat Revision model, you'll notice there seems to be a white space behind the iris of the eye, and that the iris itself is slightly concave.

The eye socket itself is painted white on the inside. The iris stays within the eye socket (so no bulging), and the concave nature of the iris allows the pupil of the eye to remain more or less in the center of the iris, regardless of viewing angle.

With the Forever Fall models, the pupil bulges out to the cornea of the eye, when anatomical models of the human eye suggest it clearly doesn't.
Anatomy of the Human Eye[www.eyephysiciansofaustin.com]
Even if anime eyes arent't realistic like this eye, how is the alternative any better?

In addition, the irises on the Combat Revision model are slightly oblong, rather than perfectly round as in the Forever Fall model. While anime may use a round iris to enhance the realism or normalness of a character, it can be agreed on that characters in RWBY aren't really supposed to be boring. As such, using the more interesting oblong iris is in order, and is in line with how the show stylizes the eyes.

How to remedy it:

• Some of the problems with a bulging eye can be fixed by reverting the eyes to the old model's style of an eye cavity and a concave iris.
  
• Using a flat recess for the eyes, like the figures in Addendum 2B.
  
• Using an oblong iris, rather than a round iris, brings the style closer to the show's design.

3. Textures

I wanted to see if I could fix most of the problems through texturing alone. Blake has really scruffy hair in the Forever Fall model, and that's partly due to the new texture applied to her hair.
Also, everyone has lips, which looks like they are sticking their tongue out when they are completely in shadow. It's really weird.
It turns out, Skilltacular wasn't wrong when they needed to do more than just fixing shaders.

Picture 3: Blake - Textures, Combat Revison, Forever Fall, Retextured Forever Fall [i.imgur.com]

Here, I've shown models as textured with no lighting. Blake's Forever Fall model's skin is slightly darker, and that's to compensate for how bright the texture gets when it's lighted. When we move to the new shaders, Blake will look sort of olive unless her texture is redone to be more bright.

If you take a look at the highlights on Forever Fall Blake's eye, they are mirrored from eye to eye, rather being in the same position. This is due to the UV mapping (texture mapping) mirroring the eye and highlights, rather applying them in the same orientation.

Highlights on an eye should be in nearly the same position on each eye, because the light strikes both eyes from the same direction.

The figure on the right in Picture 3 is my attempt to reintroduce the colors into the Forever Fall model to make it look closer to the Combat Revision model, and for the most part, it gets pretty close. However, It still suffers from the mirroring on the eyes and on the emblem on Blake's thigh, so that the emblem on Blake's right thigh is backwards.

I tried to introduce the eyelashes back into the Forever Fall model, however it doesn't to seem to work like it should. I will look into it for future work.

How to remedy it:

• Retexturing solves a lot of the problems I have with the model, but the mirroring has to be fixed with additional UV mapping.

Here's how they look in game:
Picture 4: Blake - Textures, Forever Fall & Retextured Forever Fall w/ Shadow & w/o Shadow [i.imgur.com]

Blake's pale skin color does look blown out under light, but that's to be expected. Blake in shadow, however, definitely looks like Blake.

4. Level of Detail

It's been cited multiple times that the changes to the models were made in an attempt to make the game more efficient.

The models do indeed have a lot less polygons. If you review Picture 3[i.imgur.com] again, you'll see that the sillouette of Blake's hair becomes less smooth and less detailed going from the Combat Revision to the Forever Fall Update.

So, the optimizations come at the cost of detail across the board, and it does leave higher end players sort of alienated.

While the models are detailed enough for the fast paced combat Grimm Eclipse promotes, the models are subpar for standing screenshots. What the game should be doing is culling polygons on models as the models move into the distance, if that's what it wants to do to help performance issues.

Addendum 4: So you want to increase performance, huh?

Level of Detail[www.macroseed.com]
In this picture, the renderer knows to spend less polygons to render farther away models, since they will still look about the same on the screen. When done correctly, a user shouldn't notice a difference on the model when the character is far away or when the character is close.

And of course, graphics options can allow a developer to always force high quality models or reduce the rate they deteriorate with distance.

How to remedy it:

• It's been suggested some amount times that a developer may use multiple levels-of-detail for models. Unity's LOD (Level of Detail) grouping allow for the same model type with different LODs to be accessed by the engine.
  
• The LOD Bias options in the graphics settings allow a developer to force levels of detail to allow the more detailed models on high graphics setting and the simpler, optimized models on low graphics settings.
  
• Utilizing the LOD thresholds effectively may help improve performance by culling the polygon count of far away models.

5. Other Modelling Differences

At this point, I'm just nitpicking. But these are noticable changes, and for an in-depth guide I don't think it would be fair to exclude these.
I'll let the pictures do most of the talking.

Picture 5: Ruby's Skirt[i.imgur.com]
This one is the most jarring. Go from a poofy skirt to a big chunk of skirt-like box thing.

Picture 6: Blake's Laces[i.imgur.com]
I don't think a picture of Blake is really Blake without the laces on her vest.

Picture 7: Weiss's Bolero[i.imgur.com]
It's subtle, but it's there.

6. Conclusion

Hopefully I've covered everything major. I didn't write this because I felt like somebody needed more scolding, but rather as an informative piece to detail and compare between the old and the new. Hopefully, the future will bring us good tidings.

You can take a look at the imgur gallery I used here: RWBY Model Differences[imgur.com]

Let me know how I did in the comments, and thanks for reading ^^

[gvk]

great work on the post. good explanations and examples. (and did not feel boring)

[FearJudge]

Liked that read a lot. I was not nearly as bothered by the models as some were but this post definitely highlights some issues I would've never even noticed. I also loved the material you posted and I found it really interesting.

Thanks for the post and I think you did great. :)

[Skilltacular]

This is well written and informative. If only all forum posts were this level headed and thoughtful. A thousand blessings upon you and your family's pets for generations.

[BlueFountain]

NIcely done, especially having the pics.

[cami]

Originally posted by Skilltacular:

This is well written and informative. If only all forum posts were this level headed and thoughtful. A thousand blessings upon you and your family's pets for generations.

Thanks for the read :)
I only hope this information is useful in development from here on out ^^

[Zirconius]

Originally posted by Skilltacular:

This is well written and informative. If only all forum posts were this level headed and thoughtful. A thousand blessings upon you and your family's pets for generations.

You must understand that most people don't understand the process of changing stuff like this. They (and myself initially) just see it as "this game I bought looks ugly now, wtf change it back". Glad OP made the post to inform users.

[Skilltacular]

Originally posted by Zirconius:

Originally posted by Skilltacular:

This is well written and informative. If only all forum posts were this level headed and thoughtful. A thousand blessings upon you and your family's pets for generations.

You must understand that most people don't understand the process of changing stuff like this. They (and myself initially) just see it as "this game I bought looks ugly now, wtf change it back". Glad OP made the post to inform users.

Yeah, that's what I meant by informative. It's well written and approchable. Some guys on the team read it over and felt it covered a lot of the basics.

The thousand blessings part of my comment was a simple thank you for being level headed and fair, for the most part.

[Mr Lim]

Well written and good to read through. Thanks for the info

[AI_HYPETHORP]

Really well written and informative text. Great job!
Keep up the good work!

[leucome]

Concave iris really look better and this technique is used for doll eye or realistic 3d eyes...Before adding a translucent dome/cornea over. But I guess for real-time 3d the translucent dome is not required. I noticed on the comparative picture that the white spot for highlight seem to follow a dome shape to give the illusion that there is a cornea under it.

A video of someone making polymer eyes for dolls.
https://www.youtube.com/watch?v=qWrZmDuaL-I

[Darkarcher26]

Very well done, very informative.

[cami]

Originally posted by leucome:

Concave iris really look better and this technique is used for doll eye or realistic 3d eyes...Before adding a translucent dome/cornea over. But I guess for real-time 3d the translucent dome is not required. I noticed on the comparative picture that the white spot for highlight seem to follow a dome shape to give the illusion that there is a cornea under it.

A video of someone making polymer eyes for dolls.
https://www.youtube.com/watch?v=qWrZmDuaL-I

Real good point! I didn't think of relating it to doll production.

[JOJ650s]

This is fantastic, I learned a lot.
Thanks for writing this Kami Peppers!

[D355A]

https://www.youtube.com/watch?v=5GgflscOmW8

Seriously though, nice post.
Like you pointed out, most of the complaints are due to those small details such as the skirt.
Also the eyes should be done exactly the same as the original models since they look and "feel" better.
Also the edited textures of yours are very close to the original models.

[iota-09]

i never saw the pre-patch models, so when i got in after weeks since the forever fall update, seeing these new models felt like a godsend even if they weren't perfect, but now that i've seen the old models and read this thread... yeah, i can see why people want the old models back, but there's not much one can do about that.

one problem that not many people talk about though, is the glowyness, i'm talking about the characters skin that looks to glow in a sorta-unnatural way under every lighting circumstance, i don't think this is connected to blur setting and bloom doesn't seem to change anything of it, now, i'm talking as someone who didn't watch the animation, so i don't know how it looked there, but from my point of view, this doesn't look really great; a certain amount of glow is needed, simply to give the feel of porcelaine and anime style skin, but it should be subtle, this on the other hand is massive, and you can clearly see the difference on models from the skin to anything else, what personally i would do it's either reduce it, or extend it to most parts of the model rather than only to the skin(so for someone like weiss... she'd basically look like jesus,yeah) .

other than that i don't think there's particular problems that this or other technical posts(e.g. texture mod) didn't cover, although a higher level of detail in clothes and hair shading(talking about real hair shades, not the graphical/tachnical counterpart) should probably be expanded upon when putting the game on ultra settings or (assuming you'll add one sooner or later) in an advanced graphic settings menu, when choosing what style/LoD of models.