What is OffTheGrid terrain?
OffTheGrid is a terrain technology we developed to bring detailed terrain data to in-game resolution without losing much detail. Below you can see a comparison between heightmap terrain (left), and OTG terrain (right). The OTG terrain is actually using fewer polygons.
How does it work?
We start with a high-polygon terrain, and iteratively discard the least important polygon edge (as defined by Dr. Michael Garland's quadric-based polygonal surface simplification algorithm) until we get down to our in-game polygon count target. We then apply the normals and color map from our high-polygon terrain onto our simplified mesh. Here is a wireframe image showing how OTG terrain uses less polygons by choosing them more carefully.
Why do we care?
With traditional heightmap terrain, it is only possible to accurately represent soft, rolling hills - small details like rivers, sand dunes, and cliff faces are all smoothed away by the grid. Using OffTheGrid terrain will allow us to portray a much wider variety of environments than we could with heightmap terrain. Here is an example of a small mountain detail that is destroyed by the grid (left). Please keep in mind this is just our base terrain mesh -- we are going to add vegetation, detail maps, and other environmental detail on top of this.
Now that we have an effective technique to create an efficient base mesh, do you have any other ideas for how we can improve our terrain? I have a few ideas, but I'm not sure which is the most important.(permalink)
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Everytime you post an update it makes me want to buy your game just for the engine and modding tools.
well, why don't you buy it? :O you can mess with the engine in those alpha weekly updated when you preorder
By the way -- the Overgrowth icon you see on the main moddb.com page was contributed by Tim Soret: Timsoret.com
I WANT TO MARRY YOU!
..or maybe not but I still want your SDK :)
Very nice :D
I'd buy the game for the game,
... and then when I'm done living into the role of Turner, I'd mod it and make stuff, u guys are great!
Very clever!
I feel the same like NullSoldier, though that sounds a bit disrepectful towards the uniqueness of your game itself.
If we pre-order, when can we expect to try out the engine? I have no time for anything but my project(s) at the moment, but come fall I would love to get my hands dirty with that editor.
We've been giving people weekly alphas for the past 6 months. ;) If you preorder, you can try the engine as we develop it. Now is the best time to preorder, because this is when we need the most support -- we have no investors and are funded by your preorders.
I may just buy it now >_> ...
Same here. I really want to get my hands on those modding tools.
Tried that technique 3 years ago too but ditched it due to a couple of nasty catches ( well, it's still available in the form of Terrain Meshes if people want to use it ) so test it well to see if it fits your needs. One of the problems had been memory consumption. This tech eats roughly 9-18 times more harddisk and GPU RAM ( depending if you use compressed vertices and aggressive chunking to avoid int indices ). And roughly 10 times more memory consumption on the GPU can be a show stopper especially for already large data ;) . But if you don't plan to go too high on the size of the terrain it should work. What's the target GPU ( RAM wise )?
David can answer more in detail on the implementation details, but the terrain is only a 2.2mb object file and it is actually more efficient than our previous terrain tech. We can store much more detail in the same number of tris and FPS actually increases using this new compression technique.
Ok, count on me! Hope our support helps you finish this project.
interesting technique, makes me wanna go for some graphics programming right now.
Amazing as always.
awesome idea! looks fantastic!. will u b able to adjust how much detail you want, how much mesh, and can u adjust dynamic shadows. i.e sky brighting, SSAO, and toher stuff such as fog?
Its really interesting that you used a normalmap on a terrain mesh ... i wonder how far that tech could be pushed ...
How detailed can the ground get ... could you say use one normal map to render features on the mountains (macro normal) and use another one to render the roughness of the ground right under you (micro normal)
For example, have a "micro normal" map only render a couple feet out (this would be a tiled normal transposed on the macro normal) , while discretely blending out at a distance to the "macro normal" only? ...
I guess you would have to implement a third map that indicates micro normal regions though (like what map goes where) :/ ...
Wow thats awesome O.O !
I wonder if someone can make use of the engine to give players the ability to change terrains... Ingame!
Like excessive force to certain terrains will make them sink or if you use magic or "something" to raise the terrain...
That's been done before :/ ...
Lots before.
But anyhow. I'm impressed.