Hello everyone 
I need your help, expertise or just some right directions. Offer me anything I’m grateful either way.
Just some brief history about the journey I’ve taken so far:
I recently played some Sword Art Online: Fatal Bullet which was created with the Unreal Engine 4.
Also I’m currently designing my own project, which I want to build with the Unreal Engine. I really like the art style of the newer gen anime games like Dragon Quest XI, Sword Art Online: Fatal Bullet, Hypderdimension Neptunia, Tales of and so on and I want to implement something similar for my characters, too.
Older anime games heavily rely on Cel Shading, Solid outlines and flat textures, like for instance the** Naruto Shippuuden** Games. This effect is fairly easy to reproduce but not quite the look I’m aiming for.
The Assets of the newer Tales of games feature multiple diffuse textures, one for the brightest and one for the darkest color. Depending on the degree of lighting the asset receives by the environment those two textures get mixed together to create the final look. But this still isn’t the look I’m aiming for.
The last couple of days I tried to figure out how to recreate the look of Sword Art Online: Fatal Bullet:
The problem with this is, they seem to use a completely other technique here. Some observations I made up until now are:
- **Roughness **and **Metallic **are intact with this approach, buttons and her breastplate do reflect, but not as heavy as the standard BRDF pipeline.
- Normal Mapping is considered for the lighting and Rim Light
- The models are **not **affected by the Lighting or Shadows of the Environment. They are **always **lit from the right vector of the current camera. the Lightvector rotates as the camera is rotated by the player.
- There’s a fairly subtle Rim Lighting. Every character has their own rim lighting color, based upon their texture colors.
- The cloth and hair are handled differently than the skin or eyes of the character. Seems like there are different shading methods in place for each individual body part.
- I think the **Outline **scales with screen space, don’t know if this is possible with post processing, since post processing heavily relies on texelsize. The Outlines don’t get very thick if a character is far away from the camera, so there’s some scaling in place there. But it does look too good for an inverted hull approach.
- The light doesn’t seem to be cel shaded. Well at least there’s no heavy bending in place. It does look more like some sort of matcap / gradient map approach, based upon the environment, so that the characters do look like they integrate well with the environment.
- The skin however doesn’t look very shaded at all. The Hair looks fairly realistic in movement.
- The Player Model isn’t affected by any lighting. It always has the same overall brightness.
I tried a couple of things to recreate some of this stuff with materials and researched through a couple of resources on the web, gdc talks about Guilty Gear Xrd and stuff like that but my results didn’t get any close to the look above.
Based upon my observation I jumped to some conclusions on their shading model, but I’m not quite sure about several things. For Example:
- Since the Model isn’t affected by the environment lighting, I presume that they inject a custom light vector based on the camera rotation directly to the material.
- Since it always has the same overall brightness they must use either unlit materials and calculate the light themselves (including metal and roughness) or they use the emissive channel output, but then the metal and roughness values wouldn’t be so prominent as they are in the game…
- The **Outline **could be an inverted hull, but it actually looks too good for this, so I presume it’s a scaling post process?
- The skin is just a huge riddle to me. It does look kinda shaded… but in comparison to the cloth it doesn’t look that shaded… oh well.
- The hair is fairly relalistic but stylized, but I don’t have any idea how to achive this look…
- I think that the lighting is wrapped with some kind of** gradient map **to match the environment, so that the character doesn’t look out of place.
- I think the rim lighting is controlled artistically with material instance parameters, just a color matching the overall color scheme of the characters appearance.
Basically these are just some thoughts on the artstyle itself I collected in the last couple of days.
I really need your support to crack the case if somebody can give me some insight or help me to break down the structure and push me in the right direction I really would be super grateful ^^.
Thanks in advance and sorry for the lengthy post
I’d offer a potato but I don’t know if this is applicable in the Unreal Engine Forums 
Thanks!
Dekurian