Hi all,

I've been in the process of creating a RTS game in the style of Supreme Commander (But with much bigger levels) for a while now, and whilst I've made good progress writing my own engine from scratch it has become clear that the scale of the project is way too big for one person to do in their spare time (Especially as I work fairly long hours in my day job and I like to spend as much time with my family as possible.).

So, my plan B is to look at possibly using one of the existing Game Engines out there such as the Unreal Engine, Unity etc.

I've done a couple of Udemy tutorials for Unreal, which have been quite useful, however I see that there appears to be a lot more tutorials and information out there for Unity, so I was wondering if I've backed the wrong horse.

The key feature that I need from the engine is the ability to show massive terrains, and by massive I'm not talking 5km x 5km, I'm talking more like 1000+km x 1000+km square! And unlike an FPS type game that can load in terrain segments in tiles based on your current location I need the ability to zoom the camera right out so that I can see the entire 1000km x 1000km map all at once (Although the level of detail can obviously be much lower as you zoom out). If you've played Supreme Commander then you'll be familiar with this style of "strategic zoom".

I already have this working in my own game engine by generating the terrain in realtime on the GPU using multiple octaves of Perlin noise, which has the added bonus of allowing me to smoothly tessellate the level of detail as I zoom in and out (In my engine the terrain is 4000km x 4000km). 

So the question is, what sort of terrain capabilities do the big game engines support? I'm guessing none will support realtime generated terrains?

If not then whats the maximum size pre-generated terrains that they can support? And what LOD capabilities do they have for when you zoom in/out?

Thanks in advance
Ben

P.S. I've tried doing some of my own research but all I seem to find is old forum threads that say things like "there are expected to be big improvements coming to the terrain capabilities in Unreal 4.8", which is now old and I've not seen any confirmation or details about if big improvements did indeed happen.

Unity is a very-very bad engine for large world games, out of the box. There is stuff you can buy for it to improve it but in the end you will be reworking a lot of the engine.

Unity:

In short if you want to use Unity for large terrains you will be stuck with millions of problems. Lucky it has a place where you can by all these microtransactions  tools to round off the engine.

Or you could spend years grinding learning how to make these tools yourself.

Unreal:

Unreal was build for large terrains. Everything you need is there, you don't have to buy anything extra.

A simple comparison can be done, using google image search: "Unity open world" and in a new window "Unreal open world".

This will allow you to see the average open-world of Unity VS Unreal.

Making large terrains isn't easy. A environment artist trains for around 3 years to only work on large terrains on a graphics level. If your doing everything it's going to be a pain regardless of your engine.

Thanks both for your replies,

So it looks like I'll continue to explore the limits of Unreal Engine and see if it can deliver what I need or whether I need to revert back to plan A of creating my own engine.

Thanks
Ben

7 hours ago, swiftcoder said:

That's 16 million km^2, or about 2x the total land area of the USA. That's... a really big playing field.

I'm not aware of any off-the-shelf solution to render flat terrains of that size. There are a variety of specialised vendors of spherical planetary terrains of that magnitude, for example Outerra.

Indeed, it's meant to be kind of small planet size.

In my engine the terrain is generated in realtime on the GPU so in theory the terrain could be any size and it doesn't have any impact on performance. In fact it'd probably be quite easy to make it infinite in size. The only complications would be around float precision issues, but these can be overcome.

I've looked at Outerra a few years ago. It looks very impressive, but I'm not sure how actively it's being worked on. The website looks exactly the same as when I last looked a few years ago and it still says everything is in Alpha. As far as I can see there's no option to download or buy the engine for your own use.

Do you know of any other specialised planetary engines?

Thanks
Ben

Thanks for info Swiftcoder

It seems like there are a few engines around but they seem to be mostly hobbyist projects that eventually run out of stream, just like my original attempt. I was hoping that there would be a mature major commercial game engine (Including editors and tools etc) that supported massive terrains.

I'll see how far I can get with the Unreal Engine. 

Thanks again
Ben