How to use perlin noise for 2D Tile map in top down game in Unity? - unity3d

As the title suggests I want to use perlin noise to make a randomly generated terrain using tiles that I have made with a pixel width of 32x32, I've had a little look at perlin noise but it seems very confusing and it would be great if anyone could point me into a good direction
I'll give some details into what i want to add into the game if that is needed
it will be a sort of like Minecraft game but topdown 2d, it will have the normal stuff like grass, water, sand, dirt, trees, bushes, rocks, forests, maybe already made structures? like towns or something but that would probably be used with a different type of noise I would think
Hopefully all that helps and thank you for any help you can give!

I'll simplify your case to a black/white example where your map only consists of two types of tiles, e.g. grass and sand.
Now you can go over your map and determine for every tile if it should be sand or grass by sampling the noise function at the position of the tile; if your noise creates values in the range [0, 1] you could just split it in the middle and say every tile with a value below .5 is sand, every other tile is grass.
Now a next step to consider is how to handle edges. There are two possibilities to take here.
Addendum: I think Unity has out-of-the-box solutions for this, but in case you want or have to implement it yourself:
1. Option: Have tiles for every neighbour-combination: If you look at this tileset from Pokemon, you see in the top left corner a sand tile. This can be used in case all eight neighbours are also sand. Next to it is a tile with a grass edge on the left. This can be used for the case that all three left neighbours are grass, like this:
🟩🟨🟨
🟩❌🟨
🟩🟨🟨
And that pattern goes on. you basically have a tile option for every 8² possible neighbour-combinations. (Note that Pokemon does not have all combinations).
Also notable here is that you have a clear 'background'-tile. In Pokemons case the grass. The edges are drawn onto the sand tiles.
2. Option: Have tiles for in between your sampled points. This is called Wang-Tiles, more details here.
Adding more than two types of tiles
If you want more than two types of tiles you have also multiple options.
1. Option: Multiple tile types from one noise function. You could sample your noise function kind of like a heightmap and say everything below .2 is water, everything between .2 and .3 is sand, between .3 and .8 is grass and above .8 is snow. This just uses one noise function, so it is rather simple, but you will likely recognize the layers (meaning snow will never be generated next to sand or water).
2. Option: A multi-noise biome system (like minecraft does if I'm not mistaken). You can e.g. use two separate noise functions to sample temperature and precipitation (again, like minecraft if I'm not mistaken) and then look up the value on a chart to determine the biome (which can determine the ground tile type). Here is an example of such a biome map:
3. Option: This is just a placeholder to tell you that there are other (infinite) ways to determine the floor texture for your game. Have a look at my collection of resources, I'm sure you'll find something there.
Mix your methods!
In the end what you probably want to go for is complex logic to determine your ground type. Mix and match the methods you find. E.g. use some biome map, but additionally a height map to determine where water is. Or add another noise layer that determines corruption from an evil force. Or you have a separate noise functions for vegetation. The possibilities are endless.

Related

How to have a generator class in shader glsl with amplify shader editor

i want to create a shader that can cover a surface with "circles" from many random positions.
the circles keep growing until all surface covered with them.
here my first try with amplify shader editor.
the problem is i don't know how make this shader that create array of "point maker" with random positions.also i want to controll circles with
c# example:
point_maker = new point_maker[10];
point_maker[1].position = Vector2.one;
point_maker[1].scale = 1;
and etc ...
Heads-up: That's probably not the way to do what you're looking for, as every pixel in your shader would need to loop over all your input points, while each of those pixels will only be covered by one at most. It's a classic case of embracing the benefits of the parallel nature of shaders. (The keyword for me here is 'random', as in 'random looking').
There's 2 distinct problems here: generating circles, and masking them.
I would go onto generating a grid out of your input space (most likely your UV coordinates so I'll assume that from here), by taking the fractional part of the coords scaled by some value: UV (usually) go between 0 and 1, so if you want 100 circles you'd multiply the coord by 10. You now have a grid of 100 pieces of UVs, where you can do something similar to what you have to generate the circle (tip: dot product a vector on itself gives the square distance, which is much cheaper to compute).
You want some randomness, so you need to add some offset to the center of the circle. You need some sort of random number (there might be some in ASE I can't remember, or make one your own - there's plenty of that you look online) that is unique per cell of the grid. To do this you'd input the remainder of your frac() as value to your hash/random method. You also need to limit that offset depending on the radius of the circle so it doesn't touch the sides of the cell. You can overlay more than one layer of circles if you want more coverage as well.
Second step is to figure out if you want to display those circles at all, and for this you could make the drawing conditional to the distance from the center of the circle to an input coordinate you provide to the shader, by some threshold. (it doesn't have to be an 'if' condition per se, it could be clamping the value to the bg color or something)
I'm making a lot of assumptions on what you want to do here, and if you have stronger conditions on the point distribution you might be better off rendering quads to a render texture for example, but that's a whole other topic :)

How can I make dynamically generated terrain segments fit together Unity

I'm creating my game with dynamicly generated terrain. It is very simple idea. There are always three parts of terrain: segment on which stands a player and two next to it. When the player is moving(always forward) to the next segment new one is generated and the last one is cut off. It works wit flat planes, but i don't know how to do it with more complex terrain. Should I just make it have the same edge from both sides(for creating assets I'm using blender)? Or is there any other option? Please note that I'm starting to make games with unity.
It depends on what you would like your terrain to look like. If you want to create the terrain pieces in something external, like Blender, then yes all those pieces will have to fit together seamlessly. But that is a lot of work as you will have to create a lot of pieces that fit together for the landscape to remain interesting.
I would suggest that you rather generate the terrain dynamically in Unity. You can create your own mesh using code. You start by creating an object (in code), and then generating vertex and triangle arrays to assign to the object, for it to have a visible and sensible mesh. You first create vertices at specific positions and then add triangles that consist of 3 vertices at a time. If you want a smooth look instead of a low poly look, you will reuse some vertices for the next triangle, which is a little trickier.
Once you have created your block's mesh, you can begin to change your code to specify how the height of the vertices could be changed, to give you interesting terrain. As long as the first vertices on your new block are at the same height (say y position) as the last vertices on your current block (assuming they have the same x and z positions), they will line up. That said, you could make it even simpler by not using separate blocks, but by rather updating your object mesh to add new vertices and triangles, so that you are creating a terrain that is just one part that changes, rather than have separate blocks.
There are many ways to create interesting terrain. One of the most often used functions to generate semi-random and interesting terrain, is Perlin Noise. Another is his more recent Simplex noise. Like most random generator functions, it has a seed value, which you can keep track of so that you can create interesting terrain AND get your block edges to line up, should you still want to use separate blocks rather than a single mesh which dynamically expands.
I am sure there are many tutorials online about noise functions for procedural landscape generation. Amit Patel's tutorials are good visual and interactive explanations, here is one of his tutorials about noise-based landscapes. Take a look at his other great tutorials as well. There will be many tutorials on dynamic mesh generation as well, just do a google search -- a quick look tells me that CatLikeCoding's Procedural Grid tutorial will probably be all you need.

Drawing a 3D arc and helix in SceneKit

A recent question here made me think of SceneKit again, and I remembered a problem I never solved.
My app displays antenna designs using SK. Most antennas use metal rods and mesh reflectors so I used SCNCylinder for the rods, SCNPlane for the reflector and SCNFloor for the ground. The whole thing took a couple of hours, and I'm utterly noob at 3D.
But some antennas use wires bent into arcs or helixes, and I punted here and made crappy segmented objects using several cylinders end-to-end. It looks ass-tastic.
Ideally I would like a single object that renders the arc or helix with a cylindrical cross section. Basically SCNTorus, but with a start and end angle. This post talks about using a UIBezierPath in SK, but it uses extrude to produce a ribbon-like shape. Is there a way to do something similar but with a cylinder cross section (like a partial SCNTorus)?
I know I can make a custom shape by creating the vertexes (and normals and such) but I'm hoping I missed a simpler solution.
An arc you can do with SCNShape. Start with the technique from my other answer to get an extruded, ribbon-like arc. You'll want to make sure that the part where your path traces back on itself is offset by a distance the same as your extrusion depth, so you end up with a shape that's square in cross section.
To make it circular in cross section, use the chamferProfile property — give it a path that's a quarter circle, and set the chamfer radius equal to half the extrusion depth, and the four quarter-circle chamfers will meet, forming a circular cross section.
A helix is another story. SCNShape takes a planar path — one that varies in only two dimensions — and extrudes it to make a three-dimensional solid. A helix is a path that varies in three dimensions to start with. SceneKit doesn't have anything that describes a shape in such terms, so there's no super simple answer here.
The shader modifier solution #HalMueller alludes to is interesting, but problematic. It's simple to use a modifier at the geometry entry point to make a simple bend — say, offset every y coordinate by some amount, even by an amount that's a function of why. But that's a one-dimensional transform, so you can't use it to wrap a wire around on itself. (It also changes the cross section.) And on top of that, shader modifiers happen on the GPU at render time, so their effects are an illusion: the "real" geometry in SceneKit's model is still a cylinder, so features like hit testing apply to that and not to the transformed geometry.
The best solution to making something like a helix is probably custom geometry — generating your own vertex data (SCNGeometrySource). The math for finding the set of points on a helix is pretty simple if you follow that shape's definition. To wrap a cross section around it, follow the Frenet formulas to create a local coordinate frame at each point on the helix. Then make an index buffer (SCNGeometryElement) to stitch all those points into a surface with triangles or tristrips. (Okay, that's a lot of hand-waving around a deep topic, but a full tutorial is too big for an SO answer. This should be enough of a breadcrumb to get started, though...)
Here are some starting points that might help.
One approach would be to use more cylinders and make them shorter. That's the same idea behind the various segmentCount properties on the SCNGeometry primitives. Can we see a screenshot of the current linked cylinders version?
If you increase the heightSegmentCount, you could use the approach outlined here: scenekit, how to bend an object.
I just took a look at SCNShape. I was thinking you could use a shader modifier to warp the extruded shape into a circular cross section. But SCNShape doesn't seem to expose a segment count property, which I think you'd need to create enough extrusion segments for a good look. The chamferRadius and chamferProfile properties look interesting. I wonder if you could use those to create an extrusion that looks good.

Using a neural network with genetic algorithm for pong or supermario

I'm trying to use GA to train an ANN whose job is to move a bar vertically so that it makes a ball bounce without hitting the wall behind the bar, in other words, a single bar pong.
I'm going to ask it directly because i think to know what the problem is.
The game window is 200x200 pixels, so i created 40000 input neurons.
The obvious doubt is: can GA handle chromosomes of 40000(input)*10(hidden)*2 elements(genes)?
Since i think the answer is no(i implemented this solution and doesn't seem to work), the solution seems simple, i feed the NN with only 4 parameters which are the coordinates x,y of bar and ball, nailed it.
Nice solution, but the problem is: how can i apply such a solution in a game like supermario where the number of enemies in the screen is not fixed? Surely i cannot create a NN with dynamic numbers of inputs.
I hope you can help me.
You have to use features to represent your state. For example, you can divide the screen in tiles and assign a value according to a function that takes into account the enemy (e.g., a boolean if the enemy is in the tile or the distance to the closest enemy).
You can still use pixels but you might need to preprocess them in order to reduce their size (e.g., use a recurrent NN).
Btw, a NN might not be able to handle 200x200 pixels, but it was able to learn to play Atari games using a representation of the state by preprocessed pixels of size 84x84x4 (see this paper).

Why does merging geometries improve rendering speed?

In my web application I only need to add static objects to my scene. It worked slow so I started searching and I found that merging geometries and merging vertices were the solution. When I implemented it, it indeed worked a lot better. All the articles said that the reason for this improvement is the decrease in number of WebGL calls. As I am not very familiar with things like OpenGL and WebGL (I use Three.js to avoid their complexity), I would like to know why exactly it reduces the WebGL calls?
Because you send one large object instead of many littles, the overhead reduces. So I understand that loading one big mesh to the scene goes faster than many small meshes.
BUT I do not understand why merging geometries also has a positive influence on the rendering calculation? I would also like to know the difference between merging geometries and merging vertices?
Thanks in advance!
three.js is a framework that helps you work with the WebGL API.
What a "mesh" is to three.js, to webgl, it's a series of low level calls that set up state and issue calls to the GPU.
Let's take a sphere for example. With three.js you would create it with a few lines:
var sphereGeometry = new THREE.SphereGeometry(10);
var sphereMaterial = new THREE.MeshBasicMaterial({color:'red'});
var sphereMesh = new THREE.Mesh( sphereGeometry, sphereMaterial);
myScene.add( sphereMesh );
You have your renderer.render() call, and poof, a sphere appears on screen.
A lot of stuff happens under the hood though.
The first line, creates the sphere "geometry" - the cpu will a bunch of math and logic describing a sphere with points and triangles. Points are vectors, three floats grouped together, triangles are a structure that groups these points by indecis (groups of integers).
Somewhere there is a loop that calculates the vectors based on trigonometry (sin, cos), and another, that weaves the resulting array of vectors into triangles (take every N , N + M , N + 2M, create a triangle etc).
Now these numbers exist in javascript land, it's just a bunch of floats and ints, grouped together in a specific way to describe shapes such as cubes, spheres and aliens.
You need a way to draw this construct on a screen - a two dimensional array of pixels.
WebGL does not actually know much about 3D. It knows how to manage memory on the gpu, how to compute things in parallel (or gives you the tools), it does know how to do mathematical operations that are crucial for 3d graphics, but the same math can be used to mine bitcoins, without even drawing anything.
In order for WebGL to draw something on screen, it first needs the data put into appropriate buffers, it needs to have the shader programs, it needs to be setup for that specific call (is there going to be blending - transparency in three.js land, depth testing, stencil testing etc), then it needs to know what it's actually drawing (so you need to provide strides, sizes of attributes etc to let it know where a 'mesh' actually is in memory), how it's drawing it (triangle strips, fans, points...) and what to draw it with - which shaders will it apply on the data you provided.
So, you need a way to 'teach' WebGL to do 3d.
I think the best way to get familiar with this concept is to look at this tutorial , re-reading if necessary, because it explains what happens pretty much on every single 3d object in perspective, ever.
To sum up the tutorial:
a perspective camera is basically two 4x4 matrices - a perspective matrix, that puts things into perspective, and a view matrix, that moves the entire world into camera space. Every camera you make, consists of these two matrices.
Every object exists in it's object space. TRS matrix, (world matrix in three.js terms) is used to transform this object into world space.
So this stuff - a concept such as "projective matrix" is what teaches webgl how to draw perspective.
Three.js abstracts this further and gives you things like "field of view" and "aspect ratio" instead of left right, top bottom.
Three.js also abstracts the transformation matrices (view matrix on the camera, and world matrices on every object) because it allows you to set "position" and "rotation" and computes the matrix based on this under the hood.
Since every mesh has to be processed by the vertex shader and the pixel shader in order to appear on the screen, every mesh needs to have all this information available.
When a draw call is being issued for a specific mesh, that mesh will have the same perspective matrix, and view matrix as any other object being rendered with the same camera. They will each have their own world matrices - numbers that move them around around your scene.
This is transformation alone, happening in the vertex shader. These results are then rasterized, and go to the pixel shader for processing.
Lets consider two materials - black plastic and red plastic. They will have the same shader, perhaps one you wrote using THREE.ShaderMaterial, or maybe one from three's library. It's the same shader, but it has one uniform value exposed - color. This allows you to have many instances of a plastic material, green, blue, pink, but it means that each of these requires a separate draw call.
Webgl will have to issue specific calls to change that uniform from red to black, and then it's ready to draw stuff using that 'material'.
So now imagine a particle system, displaying a thousand cubes each with a unique color. You have to issue a thousand draw calls to draw them all, if you treat them as separate meshes and change colors via a uniform.
If on the other hand, you assign vertex colors to each cube, you don't rely on the uniform any more, but on an attribute. Now if you merge all the cubes together, you can issue a single draw call, processing all the cubes with the same shader.
You can see why this is more efficient simply by taking a glance at webglrenderer from three.js, and all the stuff it has to do in order to translate your 3d calls to webgl. Better done once than a thousand times.
Back to those 3 lines, the sphereMaterial can take a color argument, if you look at the source, this will translate to a uniform vec3 in the shader. However, you can also achieve the same thing by rendering the vertex colors, and assigning the color you want before hand.
sphereMesh will wrap that computed geometry into an object that three's webglrenderer understands, which in turn sets up webgl accordingly.