[keyle]

Architecturally it's perfectly fine, designing the 3D world is just as capable as the 2D world in terms of tooling. It's more a performance concern. The biggest pain is the lack of proper face culling. It does object culling, meaning if you don't see it at all, it's culled. However faces, not quite.

So if you're in space, and you're flying nearby a big ship full of triangles, such as an imperial star destroyer, you run your framerate down to the ground if you render even only 5% of it, as it renders everything else as well.

You can mitigate that to some degree by breaking up objects, but even the shell being plain would still cause massive issues.

For first person, open world, or large environment type game, I'd recommend Unreal. For 3D isometric style games, it's perfectly suitable with knowing the caveats and minimal adjustments from an asset creation perspective.

[alkonaut]

> So if you're in space, and you're flying nearby a big ship full of triangles, such as an imperial star destroyer, you run your framerate down to the ground if you render even only 5% of it, as it renders everything else as well.

There is limiting of overdraw (not rendering the same pixel multiple times) which is easy with Z-buffers. There is frustum culling (not rendering triangles that are outside your FoV or facing away from you) already of course.

The final type of culling is occlusion culling which is avoiding rendering that starship because it's on the other side of a planet from your viewpoint (for example). That's not a feature of 3.X but it's a feature of 4.0. The technical details are pretty interesting, it uses Intel Embree (the raytracing library) to do a low-res raytrace to find the occlusions.

[meheleventyone]

AFAIK neither Unreal nor Unity will frustum cull the triangles of a model out of the box and although both offer some other forms of occlusion culling they also only operate at the whole model level.

[ganonm]

This is wrong. Unity has frustum culling enabled by default. You are correct that it only operates at whole model level though.

Occlusion culling in Unity is fairly straightforward. Simply requires a bake. It also supports 'occlusion areas' where you can give it a hint to do a higher resolution occlusion bake e.g. if you think the player will likely be in that area.

Edit: originally misread parent as stating Unity didn't frustum cull by default. Parent comment is correct.

[meheleventyone]

I’m not wrong just being more specific. All three engines frustum cull by default and all three do it at the level of the complete model. I said Unity and Unreal don’t frustum cull at the level of the individual triangle which was the factor the person I was replying to insinuated Godot lacked.

[ganonm]

Apologies, misread your comment as "won't frustum cull by default".

[meheleventyone]

No worries I can see how the original could have been more clear!