General Good Modelling Practices

So this is an issue that has bothered me for a while and I want to get an idea of what most people think.

In terms of modeling I’ve been taught that a single mesh should be made up of one shape if possible, e.g. if I were to make a table I would extrude the legs out from the bottom of the table top rather that just sticking four pillars at each corner, however I’ve never really been sure as to why this is and in some cases it seems unnecessary to cut a face up and extrude small amounts.

I know the UE4 forums might not be the best place to ask this question but 90% of my meshes are made for UE4 so I just would like to know if I’m doing it right.
I’ve included some images to explain what I mean as it is hard to describe.

Is it better to model things this way? (I know the topology isn’t great or efficient here, it’s just to show one way of doing it)

Or this way?

I know there are going to be pros and cons for different ways of modeling, just want to make sure I’m not doing something horribly wrong!

Thanks guys!

In terms of modeling I’ve been taught
that a single mesh should be made up
of one shape if possible, e.g. if I
were to make a table I would extrude
the legs out from the bottom of the
table top rather that just sticking
four pillars at each corner, however
I’ve never really been sure as to why
this is and in some cases it seems
unnecessary to cut a face up and
extrude small amounts.

Doing it the proper way safeguards you from issues, like light leaks and z-fighting, reduce overdraw It will also work under baked lighting more predictably and in some cases will deliver better lightmap usage efficiency.

On practice however, quite alot of things are solved with floaters. It is a balance between number of triangles, potential issues that may arise, and production speed.

I’d strongly advise you to fire up some of your favorite games and check how it is done there. There are a few software pieces that would allow you to see the wireframe view of a running game. You would be surprised with the amount of floating geometry games get away with.

Thanks for the reply and advice, yeah I thought light leaking might be one of the problems that could occur, I’ll see if I can check out some existing game meshes like you said.

You should not forget that quads that are stretched very thin can also become a problem for a GPU. Your example has some very thin quads. A flat surface does not require you to keep it as quads so you should instead focus on dividing the surface into more even sized quads or tris.