1.移动矩阵代码

float Circle(vec2 uv,vec2 center,float r,float blur)
{
    float dist = length(uv - center);
    float c = smoothstep(r + blur,r,dist);

    return c;
}

mat3 translate(vec2 to)
{
    mat3 m = mat3(1,   0,   to.x,
                  0,   1,   to.y,
                  0,   0,   1);
    return m;
}

void mainImage( out vec4 fragColor, in vec2 fragCoord )
{
    // Normalized pixel coordinates (from 0 to 1)
    vec2 uv = fragCoord/iResolution.xy;
    uv.x *= iResolution.x / iResolution.y;

    vec3 uv2 = vec3(uv,1);
    //坐标系往左移，则物体往右移
    uv2 = uv2 * translate(vec2(-0.1,0.0) * iTime);
    uv = uv2.xy;

    uv *= 3.0;
    uv = fract(uv);

    float c1 = Circle(uv,vec2(0.5,0.5),0.3,0.05);

    fragColor = vec4(c1 * vec3(1.0,1.0,0.0),1.0);
}

效果:

2.x方向

float Circle(vec2 uv,vec2 center,float r,float blur)
{
    float dist = length(uv - center);
    float c = smoothstep(r + blur,r,dist);

    return c;
}

mat3 translate(vec2 to)
{
    mat3 m = mat3(1,   0,   to.x,
                  0,   1,   to.y,
                  0,   0,   1);
    return m;
}

void mainImage( out vec4 fragColor, in vec2 fragCoord )
{
    // Normalized pixel coordinates (from 0 to 1)
    vec2 uv = fragCoord/iResolution.xy;
    uv.x *= iResolution.x / iResolution.y;
    uv *= 3.0;
    uv.x += fract(iTime);
    uv = fract(uv);

    float c1 = Circle(uv,vec2(0.5,0.5),0.3,0.05);

    fragColor = vec4(c1 * vec3(1.0,1.0,0.0),1.0);
}

效果:

3.分段处理

float Circle(vec2 uv,vec2 center,float r,float blur)
{
    float dist = length(uv - center);
    float c = smoothstep(r + blur,r,dist);

    return c;
}

mat3 translate(vec2 to)
{
    mat3 m = mat3(1,   0,   to.x,
                  0,   1,   to.y,
                  0,   0,   1);
    return m;
}

vec2 movingTile(vec2 uv){
    uv *= 3.0;
    if(fract(iTime) > 0.5){
        if(fract(uv.y * 0.5) > 0.5){
            uv.x += fract(iTime) * 2.0;
        }else{
            uv.x -= fract(iTime) * 2.0;
        }
    }else{
        if(fract(uv.x * 0.5) > 0.5){
            uv.y += fract(iTime) * 2.0;
        }else{
            uv.y -= fract(iTime) * 2.0;
        }
    }
    return fract(uv);
}

void mainImage( out vec4 fragColor, in vec2 fragCoord )
{
    // Normalized pixel coordinates (from 0 to 1)
    vec2 uv = fragCoord/iResolution.xy;
    uv.x *= iResolution.x / iResolution.y;

    uv = movingTile(uv);

    float c1 = Circle(uv,vec2(0.5,0.5),0.3,0.05);

    fragColor = vec4(c1 * vec3(1.0,1.0,0.0),1.0);
}

效果: