three.js/src/renderers/shaders/ShaderLib/background_vert.glsl.js

export default /* glsl */`
varying vec2 vUv;
uniform mat3 uvTransform;

void main() {

	vUv = ( uvTransform * vec3( uv, 1 ) ).xy;

	gl_Position = vec4( position.xy, 1.0, 1.0 );

}
`;