二喵的AIGC 卡牌接近尾声了！
链接：
AIGC制作卡牌1
AIGC制作卡牌2
最近遇到一个很头疼的问题，就是如何又流畅又生动的转场
在这个过程中，我实验了多个效果，一共写了7个转场特效，在论坛分享给大家。
预览地址：Cocos Creator | TransitionEffect-iwae
1.0 线性转场
*图片不能合图，合图需要转换UV
主图片使用默认的精灵，需要转场的图片，我们可以新建一个subTex，或者只是用透明色
线性转场相对而言，效果比较简单
#include <builtin/uniforms/cc-global>
const float tranSize = 0.1;
vec4 LinearTransition(vec4 color,vec4 mixcolor, vec2 uv, float progression,bool isUVX) {
float dir = isUVX?uv.x:uv.y;
float f = dir*(1.0-tranSize) + tranSize - (progression * (1.0 + tranSize));
float m = smoothstep(0., -tranSize,f);
color = mix(color,mixcolor,m);
return color;
}
我们使用了smoothstep ,先看下smoothstep的源码
float smoothstep(float t1, float t2, float x) {
// Scale, bias and saturate x to 0..1 range
x = clamp((x - t1) / (t2 - t1), 0.0, 1.0);
// Evaluate polynomial
return x * x * (3 - 2 * x);
}
根据x在t1和t2 之间的距离，返回0-1 的平滑过渡值，
这里使用了 f = dir (1-s)+s-p(1+s); 使选定的uv轴向，返回在进度参数下的 混合系数。
效果：
2.0 风吹线性过度
*图片不能合图
在线性过度上加入，随机的风吹效果
#include <builtin/uniforms/cc-global>
// Variables
const float tranSize = 0.25;
float rand (vec2 co) {
return fract(sin(dot(co.xy ,vec2(12.9898,78.233))) * 43758.5453);
}
vec4 WindTransition(vec4 color,vec4 mixcolor, vec2 uv, float progression) {
float r = rand(vec2(0, uv.y));
float m = smoothstep(0.0, -tranSize, uv.x*(1.0-tranSize) + tranSize*r - (progression * (1.0 + tranSize)));
color = mix(color,mixcolor,m);
return color;
}
效果：
3.0 圆形过度
#include <builtin/uniforms/cc-global>
float rule(vec2 coord)
{
vec2 uv2 = coord - vec2(0.5, 0.5);
float angle = atan(uv2.x, uv2.y);
return angle / 2.0 / 3.1416 + 0.5;
}
vec4 CircleTransition(vec4 color,vec4 mixcolor, vec2 uv, float progression) {
float rule = rule(uv);
float vague = 0.2;
float phase = progression * (1.0 + vague);
float p0 = smoothstep(rule, rule + vague, phase);
color = color * (1.0 - p0) + mixcolor * p0;
return color;
}
4.0 随机方块过度
float smoothness = 0.5; // 0-1
float rand (vec2 co) {
return fract(sin(dot(co.xy ,vec2(12.9898,78.233))) * 43758.5453);
}
const float tranSize = 10.;
vec4 RandomTransition(vec4 color,vec4 mixcolor, vec2 uv, float progression) {
float r = rand(floor(vec2(tranSize) * uv));
float m = smoothstep(0.0, -smoothness, r - (progression * (1.0 + smoothness)));
color= mix(color, mixcolor, m);
return color;
}
5.0 规则方块过度
来自shadertoy
#include <builtin/uniforms/cc-global>
const float tranSize = 32.;
vec4 BoxTransition(vec4 color,vec4 mixcolor, vec2 uv, float progression) {
vec2 fragCoord = gl_FragCoord.xy;
vec2 blockPos = vec2(progression) * cc_screenSize.xy;
vec2 p = ceil(fragCoord / tranSize) * tranSize;
float progress = (p.x + p.y) / (blockPos.x + blockPos.y);
vec2 v = abs(fragCoord - p + vec2(tranSize/2.));
if (max(v.x, v.y) * progress < tranSize/2.) {
color = mixcolor;
}
return color;
}
6.0 棱形过度
#include <builtin/uniforms/cc-global>
const float tranSize = 32.;
vec4 SideTransition(vec4 color,vec4 mixcolor, vec2 uv, float progression) {
uv.x = 1.0 - uv.x;
float xFraction = fract(gl_FragCoord.x / tranSize);
float yFraction = fract(gl_FragCoord.y / tranSize);
float xDistance = abs(xFraction - 0.5);
float yDistance = abs(yFraction - 0.5);
if (xDistance + yDistance + uv.x + uv.y < progression * 4.0) {
color = mixcolor;
}
return color;
}
7.0 燃烧转场
可以合图
float fr(vec2 c, float seed)
{
return fract(43.0 * sin(c.x + 7.0 * c.y) * seed);
}
float fn(vec2 p, float seed)
{
vec2 i = floor(p), w = p - i, j = vec2(1.0, 0.0);
w = w * w * (3.0 - w - w);
return mix(mix(fr(i, seed), fr(i + j, seed), w.x), mix(fr(i + j.yx, seed), fr(i + 1.0, seed), w.x), w.y);
}
float fa(vec2 p, float seed)
{
float m = 0.0, f = 2.0;
for (int i = 0; i < 6; i++) {
m += fn(f * p, seed) / f;
f += f;
}
return m;
}
vec4 BurnOut(vec4 MainColor, vec2 UV, float Intensity)
{
float t = fract(Intensity * 0.9999);
float cc = smoothstep(t / 1.2, t + 0.1, fa(3.5 * UV, 1.));
vec4 c = vec4(cc);
c = MainColor * c;
c.r = mix(c.r, c.r * 15.0 * (1.0 - c.a) * 8.0, Intensity);
c.g = mix(c.g, c.g * 10.0 * (1.0 - c.a) * 4.0, Intensity);
c.b = mix(c.b, c.b * 5.0 * (1.0 - c.a), Intensity);
return vec4(c.rgb, c.a);
}
合图效果：
代码：
http://learncocos.com/shader1/
Transition.zip (3.0 MB)
应用：
可以把当前画面截图，和透明色做混合，实现场景消失，或者卡牌溶解等等
~
更新了更多猫片，高清猫猫