It could be enabled, but even just enabling it comes with some downsides:
- currently we reduce rendering overhead by omitting Z positions - they're all assumed to be 0. Sending Z positions of 0 with every sprite is extra data and a bit more performance overhead.
- there's no depth buffer, since we don't need it. Enabling it might make GPUs do more work to redundantly check the depth buffer, when it has no effect, adding a bit more performance overhead.
- in the past I researched new rendering features like front-to-back rendering, which made use of the depth buffer for optimisation. Using it for 3D could significantly complicate future optimisations along the same lines.
Having said that, we could possibly have it enabled per layer (so you could for example enable 3D on just one layer, then all 3D content has to appear on that - all other layers are still 2D and are treated as underlay/overlays). But I think it's odd to add a checkbox that says "Enable 3D" when nothing in the editor actually uses that!
i was just asking for something like a resizable iframe that loads a 3d object, but a 3d layer would be amazing, it will be really cool just to be able to import 3d objects to C3 and the idea of the "3d layer" its cool.