I read a thread in Top 10 List about "Zero Thickness Geometry" and had been interested.

I tried to create that shape , then I found a certain method.

The following are pictures of a example.

You can see a tangent hole to face and two cubes that have 1 common edge but "Solid Bodies" is 1.

And watch the highlighting face, it touches to another face , but it isn't blended.

Even if you will create it by a usual method, you will face error.

Below are how to create.

At first create the shape by Surfaces.

Then key point is how you separate them.

You have to catch that 1 Surface cannot contain common point besides simple corner.

I suppose that this may be essence of ZTG.

After all , knit the Surfaces.

Then check the "Try to form solid" option.

If the option is grayout , it mean that you cannot create solid body.

In a case , you can knit them in 1 time.

In the other case , you have to knit them several times step by step.

Don't check the "Merge entities" option , it causes error.

That is obvious result because it merges surfaces that you created separately beforehand on purpose.

I suppose this option being fixed in ON by usual solid modeling method may be one of cause of the ZTG error.

I tried to create various shapes.

Below is 4 cubes touching each other , but 1 solid body.

Below is exceptional example , it is a cube with tangent hole same as first example.

But strangely all faces are not separated.

In case of this , "Merge entities" option doesn't cause error.

I was surprised that I had this. I suppose this may be a miracle caused by tolerance of calculation?

I post a data of first example.

I've created it in SW2012 so that most people could open it.

(Sorry if you are using older,  give it up or instal new.)

Please try to create other examples by yourselves.

You will see this method is available for almost ZTG shapes.

I am studying this fact now , I think there will be still new finding.

I hope this fact would be helpful for improvement of our SOLIDWORKS.

<<  English is not my language, so translation is hard overtime work for me.

If my grammar and expression are wrong, please permit kindly with

and interpret it properly. (Isn't this sentence wrong?)  >>

Thank you !