Will we be allowed to have terrains on iPhone or iPad using Unity 3.0? I have an application where I don’t actually need hills, but I’m using terrains in order to have trees. So, either having terrains, or a non-terrain way of having a lot of trees, would be useful.
Terrain will not come with Unity iPhone 3.0 from what mentioned.
Also the ipad is the very last device you want a super sized object as it has already massive enough fillrate problems without it. you can draw the whole screen 2-3 times per frame in total, wasting the first of those max 2-3 times with something thats computationally very heavy as a realtime blended terrain and the terrain will potentially be all you render at all.
also even if it was there: detail and trees would be totally out of question due to the drawcall limits
Terrain will not come with Unity iPhone 3.0 from what mentioned.
One of the appealing things about 3.0, that made me pay for it right away, is that it’s supposed to be integrated. The single application is able to publish to the various devices that you have paid for. At the moment I’m licensed for the iPhone and Pro versions, but if I want to do regular Unity work I open one application, and if I want to do iPhone work I have to open a second application. Being able to use a single application would be nice.
If I read that correctly, how will it then limit me on features that I can use? It would be a shame to still have to run two applications, or to have entire features disabled based on a Project setting. Taking terrain as an example, if I wanted to make a Myst-like game, where the user transitions from 2D view to 2D view, with each 2D view actually being a fixed camera in a 3D scene, I could achieve that even if the 3D scene was running at 1 fps. So, preventing me from doing that just because an iPhone can’t run at Halo-like frame rates would be a bad decision.
Let us use all the features, and figure out for ourselves which ones won’t work out for mobile devices.
From what mentioned, there won’t be multiple editors anymore, so no switch between them.
How the limiting / disabling is going to work will have to be seen.
But its clear that each platform has its specific restrictions and requirements, this does not only hold for desktop ↔ iphone but already desktop ↔ web.
This is due to security, hardware and legal restrictions.
The iphone is just very slow, especially when it comes to the terrain. The terrain as you know it would totally be out of question. Who knows perhaps a 64x64 or 128x128 max sized heightmap and no support for multiple terrains thats potentially doable although that is already heavily taxing the vertices / second budget.
If we assume stuff like tree and detail rendering then its worlds away from it actually at anything else than sub 1FPS framerates (aka waste of time to approach an implementation at all)
There is and likely never will be a magical “develop once have on all” workflow. But unity is worlds more approachable on that end than most others. You will have to adopt some of the things depending on the target platform but larger parts are just going to work.
Also there is another reason why you normally wouldn’t want to use the terrain system but your own models that serve all these purposes: control over drawcalls and batching
Its aside of the fillrate (the major bottleneck on ipad) the most limiting factor.
It’s not a matter of being slow; at least with pre-3GS systems, the hardware simply can’t do terrains as generated by Unity at all, aside from the memory restrictions. (And I’m not sure if even the 3GS graphics can do the necessary shaders.) An integrated editor can’t do anything about hardware limitations.
–Eric
the shader would be doable on 3GS
The problem at least the 2.x terrain would have would be its massive amount of vertices and triangles.
You have a budget of 300k - 500k vertices per second, thats 10k - 18k per frame if you want 30 FPS.
Already a 64x64 pixel hm grid eats 16k triangles and vertices …
With such stats it becomes clear why the terrain would not stand the slightest chance to make an appearance on the iPhone.
Well, the terrain LOD can substantially reduce that. It does use quite a few draw calls though; even a sparse low-res terrain with some trees can have >50 draw calls.
–Eric