Is 3D Printing just 2D printing over and over?

This is one of my technical rants.

I've seen it said that 3D printing isn't really 3D printing; that it is really just 2D printing over and over again.

This notion is tempting. But, in my opinion it is reductionist non-sense. In short, it is a statement which ignores the fact that the very same argument can be reduced further and applied to the very premise. And then it can even be applied again.

So, yes, there is a kernel of truth there. Perhaps even more than that.

However, it is almost worse than semantics. And that is because 2D printing is really just 1D printing over and over again by the same logic. And 1D printing is really just 0D printing over and over again. And all of these statements are true at all levels. of this non-sense.

Firstly, the statement is alluding to the fact that in 3D printing we tend to print by building up the object layer by layer. Each layer is technically a 2D print. They are just stacked on top of and fused to each other.

But, a 2D print is typically just a series of lines or arcs put together to compose a 2D picture. In essence it is just a stack of 1D lines and gaps composed together to form a 2D image.

And, those lines aren't produced all at once. They are actually deposited little by little. In essence... dot by dot into lines to produce those 1D element. So, it is really just an accumulation of 0D prints.

See? You can't acknowledge the existence of 2D printing as an end in and of itself, and then not apply the same line of thinking to 3D printing as well. 3D printing produces 3D prints via the same extrapolation of printing in space as 2D printing does, simply adding another dimension.

So, you either need to acknowledge that 3D printing IS 3D printing, or you need to acknowledge that most all printing are simply increasingly complex forms of sequential 0D printing.

And before you get smart and try and say "BUT SLA!!!!"... you have to keep in mind that SLA is STILL technically mass scale 0D printing. You either have a single laser moving very fast or you have a large number of lasers sintering at once and each laser is no different than an individual print head. You just have more at a time. It doesn't change that the print is produced bit by bit. Even if some of those bits are produced simultaneously.