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MINECRAFT VOXEL MAP HOW DO YOU CLEAR MAP DATA HOW TO
MINECRAFT VOXEL MAP HOW DO YOU CLEAR MAP DATA UPDATE

The time complexity of this method is linear in the number of voxels. For example, here is the mesh you would get using this approach on a 8x8x8 solid region: The absolute dumbest way to generate a Minecraft mesh is to just iterate over each voxel and generate one 6-sided cube per solid voxel. So with the preliminaries settles, let’s investigate some possible approaches: The Stupid Method: Thus our main focus in the analysis of meshing algorithms will be on how many quads they spit out. The conclusion of this digression is that of the two of these criteria, it is item 1 which is ultimately the most important (and unfortunately also the most difficult) to address. In this way, one could conceivably achieve the best of both worlds. Once the high quality mesh is built, the low quality mesh can then be replaced. Then, when we have some idle cycles (or alternatively in another thread) we can run the better mesher on them at some later point. If we have a fast, but dumb, mesher we can just run that on any meshes that have changed recently, and mark the geometry that changed for remeshing later on.

Over the long term, maybe we would end up getting a better FPS with the sophisticated method, while in the short term the dumb algorithm might be more responsive (but we’d pay for it down the road).įortunately, there is a simple solution to this impasse. Supposing that we were given two such algorithms, it is not a-priori clear which method we should prefer. One could imagine a super-mesher that does a big brute force search for the best mesh compared to a faster, but dumber method that generates a suboptimal mesh. Intuitively, it seems like there should be some tradeoff here. Therefore, we come to our second (and final) criteria for assessing mesh algorithms: Criteria 2: The latency of meshing cannot be too high.

MINECRAFT VOXEL MAP HOW DO YOU CLEAR MAP DATA UPDATE

It would be unacceptable to wait for more than a frame or two to update the displayed geometry in response to some user change. While it is true that chunk updates are rare, when they do happen we would like to respond to them quickly. Of course, the above analysis is at least a little naive. The only way this cost can be reduced is by reducing the total number of polygons in the mesh, and so we make the following blanket statement about Minecraft meshes: Criteria 1: Smaller meshes are better meshes. In general, there really isn’t any way to change the number of pixels/fragments which need to be drawn without changing either the resolution, framerate or scene geometry and so for the purposes of rendering we can regard this as a fixed cost (this is our second assumption). That leaves primitive assembly, and the cost of this operation is strictly a function of the number of faces and vertices in the mesh. Recall that at a high level polygon rendering breaks down into two parts: 1.) primitive assembly, and 2.) scan conversion (aka polygon filling).

Thus, over the lifetime of a mesh, the total amount of computational work it consumes is asymptotically dominated by the cost of rendering. As a result, it is quite sensible to cache the results from a mesher and only ever call it when the geometry changes. In a typical Minecraft game chunks do not get modified that often compared to how frequently they are drawn. I hope you are convinced that making these assumptions does not appreciably change the core of the meshing problem (and if not, well I’ll try to sketch out in the conclusion how the naive version of these algorithms could be extended to handle these special cases.)

Finally, we shall suppose that our chunks are stored naively in a flat bitmap (array).

Similarly we won’t make any assumptions about the position of the camera, nor will we consider any level of detail type optimizations.

Instead of having multiple block types with different textures and lighting conditions, we’ll suppose that our world is just a binary 0-1 voxel map.

For the sake of exposition, we’ll consider meshing in a very simplified setting: But before doing this, we first need to say a bit more precisely what exactly meshing is (in the context of Minecraft maps) and what it means to do meshing well. This process is called meshing, and in this post I’m going to discuss three different algorithms for solving this problem.

MINECRAFT VOXEL MAP HOW DO YOU CLEAR MAP DATA HOW TO

The main challenge in using polygons is figuring out how to convert the voxels into polygons efficiently. One of the main innovations in Infiniminer (and Minecraft) is that they use polygons instead of raycasting to render their volumes. This time I’ll try to tackle a different problem: Meshing The last post I wrote on Minecraft-like engines got a lot of attention, and so I figured it might be interesting to write a follow up.