# Tagged Questions

A regular tessellation of a surface to create uniform, contiguous cells arranged in a consistent pattern.

7k views

### Can I prevent diagonal movement from exploring more of the map?

In a tile-grid where movement in any of 8 directions takes exactly the same amount of turns (chess-board style rules), can I prevent diagonal movement from showing more new tiles than orthogonal ...
14k views

### Why don't we use octogonal maps instead of hexagonal maps?

I understand the advantage of hexagonal tiles over square ones. But why aren't octagons used instead? I would think they would provide better, more natural movement in eight directions. I was ...
4k views

### Simulating pressure in a grid based liquid simulation

I have a 2D grid based water system in my XNA game, we have a method using cellular automata to simulate water falling and spreading. Example of water flowing down a slope: Each tile can contain a ...
33k views

### Hexagonal grid/tiles tutorials [closed]

Are there any platform or language agnostic (preferably step by step) tutorials regarding creating hexagonal grid based maps/games? I'm mainly interested in grid/tiles basics and not advanced game ...
3k views

### How to render infinite universe?

I'm curious what are the best practices in game development industry to render 3d universe? To be more specific: The data points are given and static. Each point has position, color and size; The ...
413 views

### Territory patrol planning

I am developing a game/simulation where agents are fighting for land. I have the situation shown in the picture below: These creatures are walking around and occupying pieces of land they step on ...
2k views

### How can I optimize a collision engine where order is significant and collision is conditional based on object group?

If this is your first time on this question, I suggest reading the pre-update part below first, then this part. Here's a synthesis of the problem, though: Basically, I have a collision detection ...
2k views

### Get ring of tiles in hexagon grid

Thanks to this post I'm able to collect adjacent tiles to a given tile. But I'm pretty much stuck on an algorithm that gives me only a "ring" of tiles specified by an offset. The algorithm given in ...
2k views

### Finding shapes in 2D Array, then optimising

I've just been allowed an image...The image below from my game shows some darkened blocks, which have been recognised as being part of a "T" shape. As can be seen, the code has darkened the blocks ...
8k views

### Road / river generation on 2d grid map

This is a newbie question, but here it goes: My map is a 2d grid, and I want to generate roads and rivers. The route from the starting to ending point must not be the optimal route in number of tiles....
2k views

### How do I generalise Bresenham's line algorithm to floating-point endpoints?

I'm trying to combine two things. I'm writing a game and I need to determine the grid squares lying on a line with the floating-point endpoints. Moreover I need it to include all the grid squares ...
478 views

### Falling Blocks and complex shapes

I currently have a simple Tetris-like game and have come across a problem I cannot solve. Unlike Tetris where there is a single falling shape, I have multiple, potentially interlocking shapes that ...
1k views

### Generating a town layout in a grid

I want to generate a town layout in a square grid (rendered isometrically, but that doesn't matter) using the following elements: 2x2 Houses Roads, 1 unit wide Canals, 1 unit wide Sample layout: ...
3k views

### Storing a Hex Grid

I've been creating a small hex grid framework for Unity3D and have come to the following dilemma. This is my coordinate system (taken from here): It all works pretty nicely except for the fact I ...
4k views

### How do I rotate a structure of hexagonal tiles on a hexagonal grid?

My 2D isometric game uses a hexagonal grid map. In reference to the image below, how do I rotate the light blue hexagon structures by 60 degrees around the pink hexagons? EDIT: Main hex is (0,0). ...
2k views

### How to find 2D grid cells swept by a moving circle?

I'm making a game based on a 2D grid, with some cells passable and some not. Dynamic objects can move continuously, independent of the grid, but need to collide with impassable cells. I wrote an ...
151 views

### Flowfield density conversion

I'm trying to implement flowfield navigation, as described in http://grail.cs.washington.edu/projects/crowd-flows/ but I can't understand how the Density Function in Figure 4 of the paper is supposed ...
1k views

### Determine if a set of tiles on a grid forms an enclosed shape

Given a set of tiles on a grid, I want to determine: If the tiles make an enclosed figure If the tiles make an enclosed figure when you count the sides of the board as an edge of the figure If ...
379 views

### Square Grid Polygonal Terrain Query algorithm?

I have a square, fixed-grid terrain with one terrain type per grid unit in my game, and I want to do an arbitrary polygonal terrain query which returns all of the grid units enclosed/intersected by ...
440 views

### Inconsistent movement / line-of-sight around obstacles on a hexagonal grid

In a roguelike game I've been working on, one of my core design goals has been to allow the player to "Play the game, not the grid." In essence, I want the player's positioning to be tactical, ...
602 views

### How can I calculate “All squares within R” in a natural looking manner?

I'm working with a square grid, and I have a couple of effects that target all squares within R; in other words, a circular (or spherical) effect. But, circles being, well, circular, and squares ...
4k views

### Generating triangles from a square grid

I have a 2D square grid of values representing terrain elevations, and I want to generate triangles from that grid to make a 3D view of the terrain. My first thought was to split each square ...
5k views

### More efficient way to implement Line of sight on a 2d grid with ray casting?

Consider a 2d grid of tiles, and an approximated sphere of coordinates - centered on the player - that represents line of sight. The goal is to block the line of sight beyond obstacles (ie walls). It'...
5k views

### How can I snap a game object's position to a grid?

I'm making a game that involves "falling block" gameplay elements. The problem is, I'm not quite sure how to make it so that the blocks will snap to some kind of grid, in other words, I'm not sure how ...
4k views

### Simulating “line of sight” with obstacles on 2d grid?

Ran into an interesting problem. I need to figure out how to simulate line of sight - simple enough, just on a 2d grid with obstacles. Either a grid cell is visible, or it's not. I can get something ...
2k views

### Grid/cell based light system

I am working on a top-down, 2d cell-based RPG game. I would like to implement a cell based lighting system, something like this and this. I basically have several light sources and light deteriorates ...
3k views

### Technical differences between square and hexagon for a grid?

I'm developing a 2D city-building game and trying to decide on the type of grid. There will be vehicles, so the unit movement is important too. I know there are visual differences for using Squares ...
788 views

### Get position of tile in tileset

How can I get the position of tile 14 (or any other) when only knowing the following: Tile ID: 14 Rows: 4 Columns: 7 The end result should be 2x4.
603 views

### Storing walls that are between tiles

I am writing isometric engine in c++. I decided to take a more realistic approach and make walls occupy space between two tiles, not a single whole tile, as shown in the picture below (just like in ...
2k views

### A star pathfinding and discrete/smooth positions

The A* (A-star) algorithm usually represents a path on a grid. Once a path has been found, however, the path looks blocky and is not suited if you move your units with floating point datatypes. Here ...
312 views

### AI, Pathfinding - Searching Behavior

I'm developing a top-down 2D game mostly based off a tilemap/grid. The player will be able to build structures on this grid while other objects like vehicles will move around freely. I've been working ...
710 views

### Finding cells between two points (along line) to finding obstacles

My game is in 3D environment partitioned with 2D grids in 2 dimensioned array So I can get any cell/node by passing row and col like return _nodes[r][c]. When the an attacker attacks an enemy with ...
4k views

### 3D terrain map with Hexagon Grids

I'm working on a hobby project (I'm a web/backend developer by day) and I want to create a 3D Tile (terrain) engine. I'm using XNA, but I can use MonoGame, OpenGL, or straight DirectX, so the answer ...
117 views

### List cells in a 2D grid that belong in a sector / portion of a circle

Are there any algorithms to find out which cells in a 2D grid lie inside/is part of a slice of a circle - a pie slice shaped region? Essentially, as per image below, I need to list out all the green ...
195 views

### Map building grid to planet

I'm trying to build a space game and one of the key parts is building on spherical planet. I want the buildings to be build on a grid (some building are 1x1, some 6x4,..., kinda like StarCraft). My ...
4k views

### Algorithm to fit shapes to 2D grid?

Let's say you have an n-by-m grid. Some squares are occupied, some are not. You want to know where in the grid you can fit arbitrary shapes such as to not hit an occupied square. The shapes would ...
273 views

### Is there algorithm for boxcasting or thickray casting?

I am not sure what the correct name is called but here is my problem: I have implemented a casting ray function that works as expected. However, because I am using a loose grid structure, (ie, objects ...
821 views

### Creating the nodes for path finding during run time - more like path making and more

I'm making my 1st game. I'm using javascript as I currently want to learn to make games without needing to learn another language but this is more of a general game dev question. It's a 2d turn-based ...
170 views

### How to test for adjacency?

I need to come up with a better way to test for adjacency in a grid environment. Imagine that the blue is water, the green is land, and the red dot is a character. What I need to do is efficiently ...
569 views

### How to create a grid based on random shapes?

How to create a "grid" using actionscript like the image below? Basically you have an area of 1100x615 which should be filled with shapes that could be rotated and scaled... Collision detection ...
639 views

### Space Invaders-type game: Keeping the enemies aligned with each other as they turn around?

OK, so here's the lowdown of the problem I'm trying to solve. I'm developing a game in PyGame that's a cross between Space Invaders and Columns. I'm trying to make the motion of the enemies similar ...
445 views

### Best way to handle cornering in a 2D maze game?

I want to implement smooth cornering in a grid, much like Pacman moving in his maze. A big difference with Pacman, my characters can stop- thus the player has to keep pressing the controls to keep ...
385 views

### Grids and vertices

I have no idea what this is even called or even to start searching how to solve this problem. So figured I would post here for any information at all. Specially looking for already known solutions to ...
13k views

### What is grid in Unity and how can I implement it?

I'm a beginner. I need to place a grid on my map in Unity and would like to access it to place a simple object on mouse click. How can I achieve this ? I am unable to understand the grid ...
375 views

### Finding a moving target in a maze

I'm making a game that is a bit of a mix of snake and pacman. Basically, two players go through the maze and each time they pick up a piece of candy, a cube is added to their tail. If one player ...
375 views

### Is moving entities between sectors of a grid spatial partitioning inefficient?

I'm using a grid system for spacial partitioning. If I have moving entities, will I have to reassign every entity to its correct section every frame? Surely this is inefficient. Have I got the wrong ...
8k views

### How to calculate corner marks of a rotated rectangle?

I've got two elements, a 2D point and a rectangular area. The point represents the middle of that area. I also know the width and height of that area. And the area is tilted by 40° relative to the ...
587 views

### How to choose cell to put entity in in an uniform grid used for broad phase collision detection?

I'm trying to implement the broad phase of my collision detection algorithm. My game is an arcade game with lot of moving entities in an open space with relatively equivalent sizes. Regarding the ...