Qt Quick 3D - Custom Materials Example
void MAIN()
{
vec2 size = vec2(textureSize(SCREEN_TEXTURE, 0));
vec2 uv = FRAGCOORD.xy / size;
vec3 view = normalize(VIEW_VECTOR);
vec3 projection = view - view * normalize(NORMAL);
vec3 refraction = projection * projection;
uv += refraction.xy * 0.5;
vec3 col = texture(SCREEN_TEXTURE, uv).rgb;
col = col * 0.8 + vec3(0.2);
BASE_COLOR = vec4(col, 1.0);
}