constructor() {
        super({
            glslVersion: GLSL3,
            uniforms: {
                tMap: { value: null },
                tDepth1: { value: null },
                tDepth2: { value: null }
            },
            vertexShader,
            fragmentShader,
            blending: NoBlending,
            depthTest: false,
            depthWrite: false
        });
    }
A depth mask pass material that discards the lesser depth.