Is this way of attaching meshes for walls, ceilings and floors safe? (see image inside)

Development Asset Creation
1

can that be “dangerous” for performance?, or is safe if the meshes are well snapped?

Im having less shadows artifacts doing this way…
thanks.

Captura.PNG

2

More individual pieces means more draw calls. This is the primary issue with that.

Also, you will have extra geometry that you cannot see, which in theory is more of a workload. However, in practice it is not an issue since your bottleneck will be the extra draw calls.

So perhaps if you are going to make a large level with many many wall segments you should combine some of them in a modeling program, and you can even export them from unreal and re-import them after you manually combine them.

In general, because each draw call has some overhead, the more geometry you can put out in a single draw call the faster it will run (although making the whole level one draw call is bad because the engine will not be able to ‘cull’ any of that geometry).

EDIT

Having said that I would not worry about performance until it becomes a problem. You can always go back and combine the meshes easily after you build your level and if you find that you have a bottleneck due to too many draw calls.

3

Makes me wonder if it would be possible to have the engine combine like materials and pass it as one draw call. If there are 100 pieces with the same material it kind of makes sense to batch them through on one pass. Don’t know if this is being looked at but just throwing it out as a possible solution.

4

I thought the culling was triangle based and not per object…
Anyway Im using “Merge Actors” for each given sections that needs at least 4 sub meshes, like hallway sections and hubs

I was more worried about the possible waste of time of the engine trying to sneak peek through the junctures and so when rendering… .although if geometry is precise and well snapped then that should not happen… but Im unsure.

5

That would cost more time than it would save. You might be referring to backface culling?

You can check that your seams are tight by using stat initviews to ensure that you are culling objects properly and that the renderer isn’t peeking through the seams. However, lighting might leak anyway, so check that simply by building your lighting with a light on the other side of the seam.

EDIT

For what it’s worth, I would personally avoid seams like that and instead opt to give them some form of thickness such as making your wall segments just that much taller.