Making big world

overburn · Post by **overburn** » Sun Jun 08, 2008 4:47 pm

How can i create a big world and use it in irrlicht?
In big i'm reffering to 10x10 somewhat km.

greenya · Post by **greenya** » Sun Jun 08, 2008 5:33 pm

It depends what level of detail you want to achieve.
- maybe a building and roads -- this is the smallest objects
- maybe a brick in the wall of the building

overburn · Post by **overburn** » Sun Jun 08, 2008 6:07 pm

i can handle the objects' ...
i am thinking about the terrain.
like i don't think i'm ever gonna get 10x10 square km in one piece... or if i am able to , it will be really cumbersome.

so how can i split the terrain into separate parts that i load each depending on the position i'm in...
kinda like oblivion

greenya · Post by **greenya** » Sun Jun 08, 2008 7:22 pm

You can look on Google Earth.
They have all the Earth but each time you zoom-in it trying to show you better level of detail, and if it found it -- it shows you it, if not -- you see more blurred old image. The same thing works for game worlds. They are represents with tiles.

So it is like:
you want 10x10 km, you can have 100 tiles with 1x1 km, which represents some region. if we have a village in tile #34, and we want to model houses and people walking on the ground -- we add new level of detail to this tile (or group of tiles) -- we modeling all 10x10 sub-tiles of #34 tile. Each sub tile represents 100x100 m size.

Another way is to model all 10x10 km area in scale of 10x10 m, so we have 1000x1000=1000000 tiles. OR 20x20 m, then we will get 500x500=250000 tiles. So you getting full detailed area 10x10 km. This is the way i believe how World of Warcraft is done. You need a whole life to model all OR whole army of level designers

-------

imho:

The Oblivion is works in two different modes: out-doors and in-doors. Out-doors mode implement good LODing (Level Of Detail). On the main map you meeting cave entrances and you getting loading screen -- Oblivion loads completely new world and let you in. This way designers can model not all caves and simply add them into the world (even at run time, just need to reload the map again to get new entrances visible and working). This is the way how it is done in Oblivion and the way how it was done in Morrowind also.

All ways has advantages and disadvantages. For example sometimes I playing Morrowind/Oblivion and really want to look into the window of the house and see someone or something interior.... but i see opaque texture .... it is whispering "please go inside the house through that door and i will show you all you want... i just need to load the world"

ultramedia · Post by **ultramedia** » Mon Jun 09, 2008 2:11 am

i LOVE oblivion, it's the main thing that keeps me busting my gut every night learning c++ and irrlicht and terrain clip mapping... all I can say is:

soon... mwoo har har har...

B@z · Post by **B@z** » Mon Jun 09, 2008 7:39 am

well, for a big world, and high performance, i recommend you to scale

i'm usign arras' tiled terrain, and scaling my models to 0,05 and it has a great performance, and a big world xD

overburn · Post by **overburn** » Mon Jun 09, 2008 8:31 am

erm... i was asking... how do i split one mesh in more lod tiles (at runtime, not at modelling)

arras · Post by **arras** » Mon Jun 09, 2008 10:41 am

Either you model all levels of detail and switch between them as needed on run time or you code some generated terrain based on common grid or something like that.

overburn · Post by **overburn** » Tue Jun 10, 2008 5:16 pm

is it possible to split the mesh ( virtually, not physically) into multiple lod-able portions?

arras · Post by **arras** » Tue Jun 10, 2008 8:00 pm

Of course. Its totally up to you. Irrlicht scene nodes store geometry in dynamic memory. You can load/discard them anytime you want ...that is dynamically. You can for example load everything at start then use some manager to render right portions of terrain while keeping rest unrendered. Or you can even load it from disk on will.

overburn · Post by **overburn** » Thu Jun 12, 2008 10:10 am

that would mean creating a custom scene node right?

arras · Post by **arras** » Fri Jun 13, 2008 9:47 am

Right. You could use Irrlicht terrain node, unfortunately there is problem getting border vertices of two terrain nodes to line up with each other when they use different LODs. Means cracks may occur in such places. But I was not testing that. May be its not that bad. Try it if you want.

BloodInch · Post by **BloodInch** » Fri Jul 04, 2008 3:37 am

for my project i ll prefer use the tile system, because you download in only a segement of map in memory .
If you look the gamebig bug bunny based on anime to same namedreate with blender its ther choice ! and its a good system, because you can work on the details , to start you make a global map with ocean and river and after you ll but in scale to 10X10 metters.
after its easy you rattach you tiles one be one on blender you have a big terrain but you not add to memory lot of polys.

Nicolas