Inflated Surface Catmull Clark

I am very new to using grasshopper but wanted to create an inflatable facade that I will be able to adjust the size. I started by creating a mesh from an offset then I run the Catmull Clark command on the mesh but it created a solid shape that doesn’t follow the edge of the original surface.

Here are some examples of the inflated surfaces I am looking to create from a base surface in my future models.

It would be helpful for a solution to this problem I’m currently having or if there is a better way to get to the result that would I desire.
Inflate Trial.3dm (157.8 KB)
Inflate (10.2 KB)

Have a try this with Kangaroo2.

Inflate (13.3 KB)


The simulated approach @HS_Kim shows will give a more realistic inflated shape, but if you just need a quick approximation you can also offset the interior vertices of a quad mesh like this: (9.1 KB)