QML ParticleSystem: How to customize the shape properties of Emitter

Question

I am practicing particle systems in QML, and for Emitter, its shape attribute seems to be defined only as EllipseShape, LineShape, and MaskShape. However, when I assign the shape attribute as Shape {}, it prompts for a type mismatch error. The three particle shapes provided by Qt by default have limitations, as particles can only be regenerated within the range of ellipses, lines, and masked shapes. In fact, I want to achieve particle regeneration at a vertex and then spray around, but Qt does not provide the so-called "PointShape {x, y}" type.

Emitter{
    id:emitter
    width:root.width
    height:root.height
    group:"a"//Specify the group of particles emitted by the emitter
    emitRate:root.maxParticleNum  //Particle emission rate, emit 100 particles per second
    maximumEmitted: root.maxParticleNum //The emission rate and the maximum number 
    lifeSpan: Emitter.InfiniteLife//Infinite lifespan
    startTime: 1000
    size:20//The size of the particle at birth
    sizeVariation: 5//Particle variation, randomly fluctuate within a certain range
    endSize:0//The size of the particle at the end of life
    //shape: MaskShape{source:"qrc:/img/mask.png"}
    shape:Shape{ }//Error here
    velocity:AngleDirection{
        angle: 0
        magnitude: 0
    }
}