Why Unreal Engine 5.7 is a BIG Deal为什么虚幻引擎5.7如此重要

Unreal's newest update, Unreal Engine 5.7, just released and it is a big deal. The reason why is the brand new Nani foliage system, which revolutionizes the way foliage is rendered in computer graphics. Plants like trees are some of the most difficult objects to render because they are made up of many different elements. A tree can have hundreds of branches and on these branches are thousands of leaves. This means a single tree mesh can easily be made up of hundreds of thousands of polygons, which are the flat planes of geometry that make up every object in 3D. The more polygons you have on screen, the longer the engine will take to render it. To create a dense forest, we have to use these high polygon trees thousands of times. Very quickly, we can end up with an environment with millions of polygons, drastically decreasing the engine's frame rates. To get around this limitation, developers use a level of detail where the object will switch to a version of itself with less polygons the further away it is from the camera. Trees generally use billboards as their lowest level of detail, which is just a flat plane with a texture. Billboards didn't look nice, and the transition between the mesh and the billboard was very noticeable in game. Vegetationrich environments used to be difficult to create before Unreal Engine 5. Thankfully, Unreal Engine 5.1 introduced Nanite for foliage. This gave us the ability to use Unreal's virtualized geometry system called Nanite on foliage, eliminating the need for level of detail and allowing for vegetation dense environments like this jungle. Every color you see is an individual polygon, and there are millions of them. Now, with Nanite on foliage, we no longer see any ugly LOD transitions and billboards at a distance. All the polygons are rendered, but we still had performance issues on large forests because Nanite had problems rendering thin and close together geometry as well as mass materials, which are what trees are made of. The polygons of a tree that is far away from the camera and oluded can still be rendered even though it doesn't have to be taking up unnecessary computational power. This is fixed in 5.7 with a new former level of detail called nanite voxels. If a nanite tree is far away, it will transition to a voxal version of itself that is automatically generated. You can think of this as a 3D block representation of the tree, almost like if the tree was made in Minecraft. Now only the trees that are close up to the camera will get the full Nani geometry render. And trees that are far away will transition to voxels, which are much easier to render than the entire tree. As the camera gets farther away from the tree, Nani will use less voxels and increase the size of the blocks. All you have to do is open up your tree and under shape preservation, select voxalize.