Refer:3D Toon Rendering in ‘Hi-Fi RUSH’

Goals

使用ue4进行卡通渲染，包括角色和场景。

优先确保60fps

画面干净锐利鲜亮

overview

Deferred lighting + toon post-processing.

Target: decouple toon rendering and gbuffer rendering. Artists can change toon postprocess volume to change areas which want to use toon shading.

use individual toon postprocessing params for each lighting layer

Shadow color

Target:Need different shadow color.

Use shadow volume ,implemented by mapping 3d texture to 3d world position.

Ambient cubemap volume to customlize ambient

Comic shader

• Lit: halftone dot

• Shadow : hatching lines

Shader on / off

Dirty GI and SSAO, remove gradation

Use smoothstep and alpha blend to anti aliasing

Tips : not suit bloom things

Avoid these halftones look like print on the camera instead of on the models(we dont want this )

Adapt to luminace strength, larger the luminace bigger

Toon lights

In base pass , change lighting in forward render.

Mostly use decal lights instead of forward lights

Step gradiation lights

Decal lights can use a decal volume to specifically assign which area needs to be lighted . Also, it will have a smaller area to lighting and better art control instead of forward lights because of the decal volume. Decal volume can be used to prevent light leaking .

Character render is not influenced by environment lighting(decal lights and forward lights).

Shadows

Shadow-only lights

use shadow-only lights to player, character and environment.

player and giant-boss’s shadow is seperated from environment cascaded shadows.

Enemy shadows

enemy shadow use capsule shadows for high performance.

For little floating in the air enemy, use cpu raycast to decal shadows

Static shadow map

艺术家手动放置摄像机生成一张深度图，使用volume以渲染这些深度图对应的阴影。

预烘焙相机的深度图。

4x4的pcf消除锯齿。

GI

ue4 light mass 烘焙时间太长

自定义一套light volumetric light map 以提高烘焙速度和可用性。

原因之一：可选择需要GI烘焙的部分区域

修改了ue4 将 光照探针按照per actor 存储 而不是per level

GI workflow

1. 用一个world volume lighting volumer actor 选择需要烘焙GI的区域

2. 开始烘焙，等待1，2mins，区域内的GI烘焙完成

Toon face shadow

Face shadow should always clean .

Problems:

1. Model normal will lead to a messy shadow

2. Face motion will break shadow shape

3. Artist cant solve 1 and 2 problems by adjusting model

Solution : mihoyo ’s sdf face shadow (i can do it ,so i dont explain it )