how grass is made in video games

hi i'm thomas and welcome back to stylize station now back in the day there technically was no grass in video games developers would simply take a grass texture and just apply it to the floor of the level these textures were either hand painted for stylized games like super mario 64 or photo bashed from real life pictures like the grass in the original halo on the map blood gulch looking back at these games it's clear that this technique hasn't aged well but at the time the average artist only had about 128 megabytes of ram to work with so of course sacrifices had to be made on the plus side this technique was great for performance as your gpu would only have to render a single texture image but no matter what we do using a simple flat plane will always just look flat sure artists are able to fake a little bit of detail using normal maps to catch the light and give the grass texture some more depth but that doesn't really solve the main issue so developers started using something called grass cards grass cards are simple 2d images of grass that utilize an alpha channel to cut out the remainder of the image a single grass card looks something like this but placing rows of cards in front of the player doesn't exactly look convincing and placing the card as a sprite so that it always faces the camera also looks like so game artists place grass cards in clumps at 90 degree angles so now when you look at this grass clump it looks somewhat decent at most angles while this is a pretty low cost solution it isn't exactly perfect as overlapping transparent objects can cause overdraw which can impact the performance of your game but the great part about this technique is that you don't have to fill your game level with thousands of these grass cards if you have a lower performance budget a lot of games place a decent grass texture on the ground and then throw a few grass clumps scattered around the ground and that often does the trick just fine now this works pretty well when you're looking at grass off to the sides but the illusion is broken when you look directly down on the grass cards from above creating these crisscross patterns where you can clearly see the grass are just simple flat plains fun fact actually this technique is still used for trees and bushes if you look closely at the branches of trees in most video games you can see that the leaves are just 2d images placed in clumps along the branches making the trees feel more full and fluffy and for a decade or so this method has been more than enough but now that processing power is beginning to grow exponentially games are starting to use 3d modeled grass by modeling a few simple blades of grass artists can group these blades of grass together into varied clumps that different size and shape then we can paint these clumps across the landscape randomly to create very interesting shapes and silhouettes for large open worlds it would take ages to manually paint these blades of grass into your game so developers are able to create procedural systems that do the majority of the heavy lifting for them placing specific types of grass in their correct biomes or creating color variation in each blade of grass to add a bit of variety now this can still be graphically intensive especially in large open worlds so developers can also swap out the 3d modeled grass for grass cards at a distance which creates the popping in of grass that you see in games like breath of wild against impact and other open world games this grass technology is getting pushed further and further every day with studios like sucker punch rendering their fields in ghost of tsushima by generating individual blades of grass on the gpu that could each have their own procedural appearances and animation so yeah that's it have a nice day

Channel: Stylized Station

Views: 459,569

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Id: 4xkROldgFOM

Length: 3min 12sec (192 seconds)

Published: Mon Jun 20 2022