DSDSWeb/static/js/Cesium-1.53/Source/Shaders/Builtin/Functions/transformPlane.glsl

vec4 czm_transformPlane(vec4 clippingPlane, mat4 transform) {
    vec3 transformedDirection = normalize((transform * vec4(clippingPlane.xyz, 0.0)).xyz);
    vec3 transformedPosition = (transform * vec4(clippingPlane.xyz * -clippingPlane.w, 1.0)).xyz;
    vec4 transformedPlane;
    transformedPlane.xyz = transformedDirection;
    transformedPlane.w = -dot(transformedDirection, transformedPosition);
    return transformedPlane;
}