🧵 3d open worlds (non-unreal)
Anonymous at Sun, 10 Nov 2024 17:14:05 UTC No. 1001272
What techniques and programs are used to create open world games?
Unreal Engine has Landscape, yes, but I'm not interested in Unreal, I'm talking older games like Skyrim, Fallout 3, or even GTA San Andreas which I replayed recently, like how the FUCK did they create those massive open worlds? Especially in SA's case I find it especially impressive, as it has both kinds of environments one would be faced with in tackling this endeavour, both natural (countryside, deserts, mountains) and man made (roads, sidewalks, skyscrapers).
I looked up possible answers on G*ogle but all answers are just news articles glorifying (rightfully so) Beth's and Rockstar's open worlds, but there aren't actual technical details like what program they even used, settings, that kind of stuff, nothing that can allow me some wannabe to even begin trying to ape their work. I did find a very useful GDC talk going over modular kits [ https://www.youtube.com/watch?v=QBA
Anonymous at Tue, 12 Nov 2024 13:24:53 UTC No. 1001470
In computer graphics the axis goes to infinity you just have to fill it with stuff. In terms of working on older hardware they just reused the same asset's and textures over and over. By messing with scale and rotation yes can make a small rock look like a mountain. Video games are all about tricking the player into thinking there's more than there is.
Anonymous at Tue, 12 Nov 2024 14:12:32 UTC No. 1001473
>>1001272
They used any and all of the 3D creations suits you'd expect. Mainly max for games.
Understand that game landscape geometry is just geometry and it was created generated with various tools in conjunction with manual hand modelling.
The main landscape mesh is split into mesh segments that have LOD geometry that the engine loads and unloads from memeory according to engine specific
asset streaming. Ontop of these landscape meshes other systems that instantiate grass, tress, rock outcrops etc are ran and they are typically proprietary
custom solutions that are tailor made for that specific game but you can find information on how to create such procedural system in numberous places.
I've written such systems in the past and I learnt about them from text like GPU Gems and random internet forums etc.
The tech behind the most impressive made open worlds out there where created by small armies of artisans that crafted the game geometry and the
asset streaming algorithms that continously loads and unloads sections of the map and handle effective culling of assets is where autistic attention
to optimization occurs. You download Open IV for GTA V and start looking at how Los santos is stitched together you gain an appreciation for how much
stellar work goes into making something like that run at high frame rates on 10+ year old hardware.
Anonymous at Tue, 12 Nov 2024 14:15:19 UTC No. 1001474
I don't think there was anything too special on the artists side, and they leaned hard on the programmers to do custom shit. Just from stuff I've read and watched about development back then, and just the stuff you notice playing those old games, I'd bet they would do the whole base of the terrain as one model in whatever, then get maths to chunk it down into squares for LODs and the custom level editor they invariably made (if they're not using Unreal or whatever), then it would be easy to texture in that.
Anonymous at Tue, 12 Nov 2024 14:17:24 UTC No. 1001475
>>1001272
>how do they go about texturing such a huge plane without using enormous textures, how do they export it into a game engine.
The mesh of the terrain is cut into sets of chunks that are optimized for effective frustum culling so you only render the portion of detailed geo
you absolutely need at any given time, each segment of the ground mesh has an upper bound of polygons they can have so you never have all the millions and millions
of polygons that the full high detail map consist of loaded into memory except the few local chunks to where you are standing.
The geometry is typically textured by mixing 2 tiling materials that have a similar look like 'GrassA' 'GrassB' that are blended between using some form of
noise map that masks the repeating pattern. Each chunk of landscape geometry than typically uses a 'splat map' to blend between up to 5 different materials.
so you use the RGBA value of the splatmap to blend between materials say 'grass' 'sand' 'debris' 'rocks' 'mud' and if you need adjacent areas to use additional
materials you make sure they share bordering materials in the splat map and swap out say your 'debris' and 'sand' material to 'dirt' and 'asphalt' on that model.
Anonymous at Tue, 12 Nov 2024 16:05:24 UTC No. 1001482
>>1001475
> Each chunk of landscape geometry than typically uses a 'splat map' to blend between up to 5 different materials. so you use the RGBA value of the splatmap to blend between materials say 'grass' 'sand' 'debris' 'rocks' 'mud'
Why 5 and not 4? I mean each channel represents how much of a single texture is visible, so lets say R=0 means fully transparent grass, R=255 means fully visible grass, if G stands for rocks, R=128 G=128 will be half-grass-half-rocks used to blend between areas and make smooth transition from one texture to another. So R,G,B,A with this encoding can get you 4 different textures, but how do you get 5?
Anonymous at Tue, 12 Nov 2024 17:10:03 UTC No. 1001485
>>1001482
Because how RGBA provides four values of how much of texture A B C and D are to be applied thru the 0-1 range in each channel.
They all blend ontop of a null/base texture that will appear where ever your splatmap has a zero/black value in all channels including alpha.
Anonymous at Tue, 12 Nov 2024 17:24:35 UTC No. 1001486
>>1001485
Oh yes, I see. Got it wrong somehow. And grayscale mask is blending between two ofc.
Anonymous at Fri, 15 Nov 2024 09:11:08 UTC No. 1001703
>>1001272
the trick to open worlds is easy
chunks.
you never load in everything at once, instead you load high-quality chunks close to the player, low quality chunks in the distance and no chunks where the player doesn't see. that's all there is to it.
how you implement those chunks is up to your engine or you.
Anonymous at Sat, 16 Nov 2024 13:31:53 UTC No. 1001778
>>1001272
i saw a video about Mario64 and how those worlds were put together, it describes what the anon is talking about in this thread, the splat maps and geometry. i tried to find it but couldn't but it is on youtube somewhere.