Is it ever okay NOT to connect vertices?

Stevorino

In a low-poly game model, is it ever okay to NOT connect vertices and instead just have a poly-face stick into a mesh?

Example: An arm connects to the shoulder of a character. You connect the shoulder vertices to the top of the arm vertices. Could it be appropriate to just have the arm stick into the body and not actually connect?

A better example may be an ear - to have an ear object just stick into the side of the head without actually connecting vertices.

If it IS appropriate at times, what are the in-game ramifications of this technique?

Thanks!

Stevorino

perna wrote: »

That's called "open edges" and whether or not you can do it depends on the engine. A mesh without open edges is also often called "water tight". There are other terms.

Of course, you'd pretty much only ever need to do something like that when the specs are extremely low and saving a handful of verts makes a difference, so there's no way of accurately answering your question without context.

This is the answer I was looking for - I was more concerned that it was just this huge no no.

I'm modeling in Blender for a Unity game. It's a PC game but I'm trying to keep it pretty accessible - I'm aiming for Torchlight/Torchlight 2 specs.

Stevorino

perfect - thanks perna!

rollin

just as a note.. the Battlemech models from Mechwarrior Online are just many many mostly open edged pieces.

Autarkis

and as another side not, remember that Unity and backfacing do not play nice together, so make sure you won't see the "inside" faces on your model when you import it into Unity.

chrisradsby

Also, not welding every vertice to each other can help your workflow a lot. Especially if you're constantly updating it, you can always weld everything together when you finalize the model. Like making a big room for an apartment, and you have all the smaller rooms as just floating faces within that space and not welded together. Makes it so that you can easily move things around if you need to.

Sage

the only issue you might get is incorrect shadows rendered if you left open edges. I'm not sure if Unity has that issue. I saw it happen on a game I was working on and was like, really...

Tiles

Normals can become an issue with not connected vertices. So use them wisely.