桶形/枕形畸变 Barrel/Pincushion Distortion

1
2
3
4
5
6
7
8
9

shader_type canvas_item;

uniform float k=0.2; // 正：桶形；负：枕形

void fragment(){
    vec2 p=UV*2.0-1.0;
    p *= 1.0 + k*dot(p,p);
    COLOR=texture(TEXTURE,(p+1.0)*0.5);
}