Restricting the range of implicit 3D function

I am new to MATLAB and have been using MATLAB as using implicit functions to render organ shapes such as kidneys and bladders. I have tried simulating a bladder shape with the elliptic function

This implicit function looks like this:

bladder2D=@(x,y) (y.^2-(x-0.5).^(3)+2*(x-0.5)-1);

fimplicit(bladder2D)

If i use the following functions, it 'stacks' the 2D layers to a 3D shape, which follows

h=fimplicit3(@bladder2);
    set(h, 'EdgeColor', 'none', 'MeshDensity', 110);

zlim([0,4*pi])
view(-130,30)

function out=bladder2(x,y,z)
   
   bladder1=@(x,y) (y.^2-(x-0.5).^(3)+2*(x-0.5)-1).*(pi*z-z.^2).^(1/2);
   
   s=@(q) min(q./(pi*z-z.^2).^(1/2),1e6);
 
   out=bladder1(s(x),s(y));                
end

There are 2 problems to solve: one is that I want to restrict the 'bladder2D' function to around , so that when rendered to 3D, it becomes a bladder shape. The point is that the x value must not be restricted in 3D form; it should be done in the 2D form.

The other problem is that there is a 'hole' on top of the bladder shape, and want to remove this 'hole'. How can i fix these problems?