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水波扩散效果

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ifengzp 2020-05-04 19:18:35 +08:00
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6
README.md
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@ -9,6 +9,7 @@ cocos是一款挺棒的游戏引擎，我在这个仓库实现一些游戏当中
# 目前已实现效果
[水波扩散（shader）](./doc/Water_spread/水波扩散效果.md)
[镜面光泽（shader）](./doc/Specular_gloss/镜面光泽.md)
[圆形头像（shader）](./doc/Circle_avatar/shader圆形头像.md)
[溶解效果（shader）](./doc/Dissolve_color/溶解效果.md)
@ -24,6 +25,11 @@ cocos是一款挺棒的游戏引擎，我在这个仓库实现一些游戏当中
2D换装
震屏效果+动画恢复第一帧
## 水波扩散（shader）
水波扩散是一个比较好看的交互效果，特别是在某些以水为故事发生场景的游戏中，扩散的水波会让场景更加栩栩如生。
![demo](.doc/Water_spread/resource/demo.gif)
## 镜面光泽（shader）
镜面上扫过一道光泽是UI里面很常用的一种特效，通常用来强调某个物体或者凸显物体的“稀有”价值，比如卡片中扫过一道光芒等

7
assets/Scene/Home/Home.ts
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@ -2,16 +2,17 @@ import BackHomeBtn from './BackHomeBtn';
const { ccclass, property } = cc._decorator;
const LOAD_SCENE_MIN_SEC: number = 1.2;
enum sceneList {
'Water_spread' = '水波扩散效果（shader）',
'Specular_gloss' = '镜面光泽效果（shader）',
'Dissolve_color' = '溶解效果（shader）',
'Follow_spot' = '追光效果（shader）',
'Circle_avatar' = '圆形头像（shader）',
'Scratch_ticket' = '刮刮卡实现',
'Coin_fly_to_wallet' = '金币落袋效果',
'Moving_ghost' = '移动残影效果',
'Magnifying_mirror' = '放大镜效果',
'Follow_spot' = '追光效果（shader）',
'Typer' = '打字机效果',
'Bullet_Tracking' = '子弹跟踪效果',
'Moving_ghost' = '移动残影效果',
'Circle_avatar' = '圆形头像（shader）',
'Infinite_bg_scroll' = '背景无限滚动',
'Change_clothes' = '换装',
'Screen_vibrating' = '震屏效果+动画恢复第一帧',

7
assets/Scene/Water_spread.meta Normal file
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93
assets/Scene/Water_spread/Water_spread.effect Normal file
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@ -0,0 +1,93 @@
// Copyright (c) 2017-2018 Xiamen Yaji Software Co., Ltd.
CCEffect %{
techniques:
- passes:
- vert: vs
frag: fs
blendState:
targets:
- blend: true
rasterizerState:
cullMode: none
properties:
texture: { value: white }
canvas_size: { value: [ 667.0, 375.0 ] }
center: { value: [ 0.5, 0.5 ] }
wave_radius: { value: 0.18 }
wave_offset: { value: 2.0 }
}%
CCProgram vs %{
precision highp float;
#include <cc-global>
#include <cc-local>
in vec3 a_position;
in vec4 a_color;
out vec4 v_color;
#if USE_TEXTURE
in vec2 a_uv0;
out vec2 v_uv0;
#endif
void main () {
vec4 pos = vec4(a_position, 1);
#if CC_USE_MODEL
pos = cc_matViewProj * cc_matWorld * pos;
#else
pos = cc_matViewProj * pos;
#endif
#if USE_TEXTURE
v_uv0 = a_uv0;
#endif
v_color = a_color;
gl_Position = pos;
}
}%
CCProgram fs %{
precision highp float;
#include <alpha-test>
#include <cc-global>
in vec4 v_color;
#if USE_TEXTURE
in vec2 v_uv0;
uniform sampler2D texture;
#endif
uniform ARGS{
vec2 center;
vec2 canvas_size;
float wave_radius;
float wave_offset;
};
void main() {
vec2 distance_vec = center - v_uv0;
distance_vec = distance_vec * vec2(canvas_size.x / canvas_size.y, 1.0);
float distance = sqrt(distance_vec.x * distance_vec.x + distance_vec.y * distance_vec.y);
// distance小于1，但是我们希望能有多个波峰波谷，所以在sin的内部乘上一个比较大的倍数
// sin函数的值在-1到1之间，我们希望偏移值很小，所以输出的时候需要缩小一定的倍数倍
float sin_factor = sin(distance * 100.0 + cc_time.x) * 0.05;
float discard_factor = clamp(wave_radius - abs(wave_offset - distance), 0.0, 1.0);
// 计算总的uv的偏移值
vec2 offset = normalize(distance_vec) * sin_factor * discard_factor;
vec2 uv = offset + v_uv0;
gl_FragColor = texture(texture, uv);
}
}%

17
assets/Scene/Water_spread/Water_spread.effect.meta Normal file
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{
"ver": "1.0.25",
"uuid": "7b534a3f-8819-43a5-87dc-5d55a6869117",
"compiledShaders": [
{
"glsl1": {
"vert": "\nprecision highp float;\nuniform mediump mat4 cc_matViewProj;\nuniform mat4 cc_matWorld;\nattribute vec3 a_position;\nattribute vec4 a_color;\nvarying vec4 v_color;\n#if USE_TEXTURE\nattribute vec2 a_uv0;\nvarying vec2 v_uv0;\n#endif\nvoid main () {\n vec4 pos = vec4(a_position, 1);\n #if CC_USE_MODEL\n pos = cc_matViewProj * cc_matWorld * pos;\n #else\n pos = cc_matViewProj * pos;\n #endif\n #if USE_TEXTURE\n v_uv0 = a_uv0;\n #endif\n v_color = a_color;\n gl_Position = pos;\n}",
"frag": "\nprecision highp float;\n#if USE_ALPHA_TEST\n#endif\nuniform highp vec4 cc_time;\nvarying vec4 v_color;\n#if USE_TEXTURE\nvarying vec2 v_uv0;\nuniform sampler2D texture;\n#endif\nuniform vec2 center;\nuniform vec2 canvas_size;\nuniform float wave_radius;\nuniform float wave_offset;\nvoid main() {\n vec2 distance_vec = center - v_uv0;\n distance_vec = distance_vec * vec2(canvas_size.x / canvas_size.y, 1.0);\n float distance = sqrt(distance_vec.x * distance_vec.x + distance_vec.y * distance_vec.y);\n float sin_factor = sin(distance * 100.0 + cc_time.x) * 0.05;\n float discard_factor = clamp(wave_radius - abs(wave_offset - distance), 0.0, 1.0);\n vec2 offset = normalize(distance_vec) * sin_factor * discard_factor;\n vec2 uv = offset + v_uv0;\n gl_FragColor = texture2D(texture, uv);\n}"
},
"glsl3": {
"vert": "\nprecision highp float;\nuniform CCGlobal {\n highp vec4 cc_time;\n mediump vec4 cc_screenSize;\n mediump vec4 cc_screenScale;\n mediump vec4 cc_nativeSize;\n highp mat4 cc_matView;\n mediump mat4 cc_matViewInv;\n mediump mat4 cc_matProj;\n mediump mat4 cc_matProjInv;\n mediump mat4 cc_matViewProj;\n mediump mat4 cc_matViewProjInv;\n mediump vec4 cc_cameraPos;\n};\nuniform CCLocal {\n mat4 cc_matWorld;\n mat4 cc_matWorldIT;\n};\nin vec3 a_position;\nin vec4 a_color;\nout vec4 v_color;\n#if USE_TEXTURE\nin vec2 a_uv0;\nout vec2 v_uv0;\n#endif\nvoid main () {\n vec4 pos = vec4(a_position, 1);\n #if CC_USE_MODEL\n pos = cc_matViewProj * cc_matWorld * pos;\n #else\n pos = cc_matViewProj * pos;\n #endif\n #if USE_TEXTURE\n v_uv0 = a_uv0;\n #endif\n v_color = a_color;\n gl_Position = pos;\n}",
"frag": "\nprecision highp float;\n#if USE_ALPHA_TEST\n uniform ALPHA_TEST {\n float alphaThreshold;\n };\n#endif\nuniform CCGlobal {\n highp vec4 cc_time;\n mediump vec4 cc_screenSize;\n mediump vec4 cc_screenScale;\n mediump vec4 cc_nativeSize;\n highp mat4 cc_matView;\n mediump mat4 cc_matViewInv;\n mediump mat4 cc_matProj;\n mediump mat4 cc_matProjInv;\n mediump mat4 cc_matViewProj;\n mediump mat4 cc_matViewProjInv;\n mediump vec4 cc_cameraPos;\n};\nin vec4 v_color;\n#if USE_TEXTURE\nin vec2 v_uv0;\nuniform sampler2D texture;\n#endif\nuniform ARGS{\n vec2 center;\n vec2 canvas_size;\n float wave_radius;\n float wave_offset;\n};\nvoid main() {\n vec2 distance_vec = center - v_uv0;\n distance_vec = distance_vec * vec2(canvas_size.x / canvas_size.y, 1.0);\n float distance = sqrt(distance_vec.x * distance_vec.x + distance_vec.y * distance_vec.y);\n float sin_factor = sin(distance * 100.0 + cc_time.x) * 0.05;\n float discard_factor = clamp(wave_radius - abs(wave_offset - distance), 0.0, 1.0);\n vec2 offset = normalize(distance_vec) * sin_factor * discard_factor;\n vec2 uv = offset + v_uv0;\n gl_FragColor = texture(texture, uv);\n}"
}
}
],
"subMetas": {}
}

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21
assets/Scene/Water_spread/Water_spread.mtl Normal file
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{
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27
assets/Scene/Water_spread/Water_spread.ts Normal file
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const { ccclass, property } = cc._decorator;
@ccclass
export default class Water_spread extends cc.Component {
@property(cc.Node)
bg: cc.Node = null;
material: cc.Material = null;
onLoad() {
this.material = this.bg.getComponent(cc.Sprite).getMaterial(0);
this.bg.on(cc.Node.EventType.TOUCH_END, this.touchStartEvent, this);
}
waveOffset: number = 0.0;
touchStartEvent(evt: cc.Event.EventTouch) {
let pos = evt.getLocation();
this.material.setProperty('center', [ pos.x / this.bg.width, (this.bg.height - pos.y) / this.bg.height]);
this.waveOffset = 0.0;
}
update(dt) {
if (this.waveOffset > 2.0) return;
this.waveOffset += dt;
this.material.setProperty('wave_offset', this.waveOffset);
}
}

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"loadPluginInNative": true,
"loadPluginInEditor": false,
"subMetas": {}
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91
doc/Water_spread/水波扩散效果.md Normal file
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# 效果演示
水波扩散是一个比较好看的交互效果，特别是在某些以水为故事发生场景的游戏中，扩散的水波会让场景更加栩栩如生。
![demo](./resource/demo.gif)
# 实现思路
如果水波静止，我们看到的其实是像素点围绕着某个中心点的拉伸效果，我们只需让每个像素点叠加上它和中心点的向量差，就能够呈现出画面上的所有像素围绕中心点的拉伸感。
```c++
void main() {
vec2 uv = normalize(vec2(0.5, 0.5) - v_uv0) * 0.2 + v_uv0;
gl_FragColor = texture(texture, uv);
}
```
![demo](./resource/stretch.png)
这个时候如果我们加上时间参数，我们就可以得到一个往外不停井喷的“黑洞”：
```c++
void main() {
vec2 uv = normalize(vec2(0.5, 0.5) - v_uv0) * 0.2 * cc_time.x + v_uv0;
gl_FragColor = texture(texture, uv);
}
```
![掏空式往外涌](./resource/demo2.gif)
但是水波往外扩散是呼吸灯式的一波波往外涌，而且不是这种无尽式的一直把东西往外掏的感觉，所以我们要给`cc_time.x`加上一个周期性的变化，让它能表现出这种周期性的往外扩散的感觉。
```c++
void main() {
vec2 uv = normalize(vec2(0.5, 0.5) - v_uv0) * 0.2 * sin(cc_time.x) + v_uv0;
gl_FragColor = texture(texture, uv);
}
```
![周期性往外涌](./resource/demo3.gif)
这种呼吸灯式的涌动其实和我们的最终效果有很大区别，因为它永远在循环涌动，但是我们的水波是从中心扩散出去之后，中间部分就不再动了的，怎么让中间的像素不再多次涌动呢？如果把一圈水波比作圆，那水波的扩散行为其实就是这个圆的半径在不断的增大，圆外面的波纹有效，圆里面的波纹静止。因此我们可以多加一个距离取样，像素离扩散中心的距离大于半径才保留否则丢弃，而这个半径从零开始逐渐增大。
```c++
void main() {
vec2 distance_vec = vec2(0.5, 0.5) - v_uv0;
float sin_factor = sin(cc_time.x) * 0.2;
float wave_radius = 0.3;
float distance = sqrt(distance_vec.x * distance_vec.x + distance_vec.y * distance_vec.y);
// 其中waveOffset是随时间增长的，通过外部传入
float dis_factor = clamp(wave_radius - abs(distance - wave_offset), 0.0, 1.0);
vec2 uv = v_uv0 + normalize(distance_vec) * sin_factor * dis_factor;
gl_FragColor = texture(texture, uv);
}
```
![未调优效果](./resource/demo4.gif)
接下来的就是参数的调试，主要是三角函数的采样那里，我们希望水波能够产生多个波动，所以我们需要乘上一定的倍数，让函数的作用范围足够大，才能有足够多的波峰谷底。另外就是sin函数的输出值域在`(-1, 1)`之间，所以我们的输出也需要缩小一定的倍数，才能让函数的峰值变化处于一个合理的范围。
```c++
void main() {
vec2 distance_vec = center - v_uv0;
distance_vec = distance_vec * vec2(canvas_size.x / canvas_size.y, 1.0);
float distance = sqrt(distance_vec.x * distance_vec.x + distance_vec.y * distance_vec.y);
// distance小于1，但是我们希望能有多个波峰波谷，所以在sin的内部乘上一个比较大的倍数
// sin函数的值在-1到1之间，我们希望偏移值很小，所以输出的时候需要缩小一定的倍数倍
float sin_factor = sin(distance * 100.0 + cc_time.x) * 0.05;
float discard_factor = clamp(wave_radius - abs(wave_offset - distance), 0.0, 1.0);
// 计算总的uv的偏移值
vec2 offset = normalize(distance_vec) * sin_factor * discard_factor;
vec2 uv = offset + v_uv0;
gl_FragColor = texture(texture, uv);
}
```
![demo](./resource/demo.gif)
# 效果预览
**源码**获取请点击**查看原文**，长按二维码**查看效果**👇
![ewm](./resource/ewm.png)
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