A 2D shape consisting of straight lines that are joined to for a circuit.

learn more… | top users | synonyms

49
votes
2answers
3k views

How can I get textures on edge of walls like in Super Metroid and Aquaria?

Games like Super Metroid and Aquaria present the terrain with the other facing parts having rocks and stuff while deeper behind them (i.e. underground) there's different detail or just black. I ...
18
votes
5answers
598 views

Moving CW or CCW?

Lets say we have a jagged shape: And two creatures moving along it's outline. Then we smooth the shape completely by pulling the corners out. We get this: It is easy to see now that Orange is ...
12
votes
3answers
583 views

What caused “falling out of the world” and what fixed it?

A lot of early 3D games had the problem where you'd be trundling merrily along and suddenly everything was black, with an island of what looked like the hollow facade shell of the scene you'd been ...
12
votes
1answer
3k views

A* navigational mesh path finding

So I've been making this top down 2D java game in this framework called Greenfoot and I've been working on the AI for the guys you are gonna fight. I want them to be able to move around the world ...
8
votes
2answers
1k views

How to create 2D game terrain?

Last month, I experimented a lot in game development using cocos2d for the iPhone, especially on moving and modifying sprites. However, vertices and polygons are still new stuff for me. I developed ...
8
votes
2answers
2k views

How do I determine if one polygon completely contains another?

I have 2 polygons. I know the vertex coordinates of both polygons. What's the best way to check if one is completely inside the other? For example, the algorithm should only recognize the black ...
7
votes
3answers
681 views

Polygon editor to draw collision data over image

I need an editor to plot a polygon over the texture for of a ship in my game. It would look like this.. Where the red is the collision outline and the image is the texture. I want to store the ...
7
votes
3answers
173 views

How can I add and subtract convex polygons?

I have two 2D convex polygons overlapping each other. I am looking for an algorithm to subtract and add them. The result must be a single concave polygon or (even better) a set of biggest convex ones ...
7
votes
1answer
220 views

How do I get the areas enclosed by an arbitrary 2D shape?

In my game I want users to be able to draw arbitrary 2D shapes of any length around game objects. The shapes must be closed and drawn with a single stroke that does not overlap. For example: I ...
6
votes
3answers
803 views

Can a straight line be called a polygon?

According to the definition of Polygon, If a Poly-line's first and last points are connected then it is called Polygon. See the image below. I have P1, .... P5 Polyline. If I draw a line from P5 to ...
6
votes
2answers
2k views

How do I handle collision detection so fast objects are not allowed to pass through walls?

I'm creating a 2d sidescrolling shooter, and I'm having a little trouble with collision detection for the bullets. Everything including the bullets are objects with their own polygons / update ...
6
votes
1answer
570 views

Puzzle game: clipping of non-convex polygons on the figures

I have an original figure in the SVG file. I need to break it randomly on parts, an example of which is specified below: I have an idea, to use for partitioning Voronoi diagram (Fortune's algorithm). ...
6
votes
1answer
128 views

Separating axis theorem with multiple polygons?

I am attempting to implement the separating axis theorem in C#. I have a function that can calculate the minimum translation vector between two polygons. However, I can't seem to create a function ...
5
votes
5answers
6k views

Any reliable polygon normal calculation code?

Do you have any reliable 3d polygonal face normal calculation code? Any language will do, I'll port it to make it work. Even if you find some code in a 3d game engine and post it here I'll be more ...
5
votes
2answers
164 views

Random 2D point in rectangle, but not in a polygon

I have a static rectangle and dynamic polygon. I need to generate a random 2D point in that rectangle, but not in a polygon. This is what I mean: Green is where random point can be generated and ...
5
votes
1answer
429 views

Algorithm for constructing the corners of a regular, n-sided polygon

I've googled this using a lot of keyword combinations, but to my great surprise I could not find an algorithm for constructing a regular, n-sided polygon into a given circle, i.e., finding the ...
5
votes
2answers
2k views

How do I align the matrix used in SpriteBatch and the matrix used in BasicEffect?

I'm writing a Windows tool that uses XNA and allows the user to place textures on the screen. I'm using a 'camera' for the SpriteBatch used to draw the textures, e.g: Matrix matrixForSpriteBatch = ...
5
votes
1answer
224 views

Splitting an object into two

I'm using Farseer physics engine. I have a simple rectangle body and would like it to split into two pieces given a starting coordinate (where the bullet enters the object) and ending coordinate ...
5
votes
1answer
447 views

Do I need to roll my own polygon segmentation algorithm to automate Box2d body creation from a tile map?

Before re-inventing the wheel I figured I'd ask: I'm working on a tile-based 2d-maze level generator for cocos2d + box2d. The idea is: I'm using one of the well-known graph traversal algorithms to ...
4
votes
4answers
179 views

What decrease of polycount should occur as a function of distance?

What decrease in polycount should occur as a function of distance. I make a terrain and I wounder what is the right formula to keep the "poly size"(the screen size) constant. Or is there some mental ...
4
votes
1answer
232 views

Is there any heuristic to polygonize a closed 2D raster shape with n triangles?

Let's say we have a 2D image black on white that shows a closed geometric shape. Is there any (not naive brute force) algorithm that approximates that shape as closely as possible with n triangles? ...
4
votes
2answers
850 views

What is a good way to determine if a vector is between two other vectors?

I could operate with the angles, but I do not have the angles calculated yet (and would like to avoid having to do that). It would be possible to calculate and cache the local-coordinate-frame angles, ...
4
votes
2answers
680 views

I need help with 2D collision response (of stacking rotating polygons, with friction and gravity, for a game)

Hi I am looking for suggestions on how to write a collision response for game programming purpose (so not a scientific simulation). I am dealing with 2D polygons that are rotating, and I want them to ...
4
votes
1answer
231 views

Polygon count budget

Is there any smart way to think about polygon budget relating to PC gaming today? My game will have one static 3d background scene and two fighters. No more enemies. I am thinking about having ...
3
votes
3answers
1k views

How did they do it: Trine 2.5d terrain?

How did they make the terrain in trine? I think they took a polygon approach. It doesn't seem that they used a heightmap because it is in all three vectors, or a voxel method because it doesn't have ...
3
votes
2answers
456 views

Scan-Line Z-Buffering Dilemma

I have a set of vertices in 3D space, and for each I retain the following information: Its 3D coordinates (x, y, z). A list of pointers to some of the other vertices with which it's connected by ...
3
votes
3answers
342 views

Adding tolerance to a point in polygon test

I've been using this method which was taken from Game Coding Complete to detect whether a point is inside of a polygon. It works in almost every case, but is failing on a few edge cases, and I can't ...
3
votes
1answer
592 views

Breakout clone, how to handle/design for collision detection/physics between objects?

I'm working on a breakout clone, and I wish to create some realistic physics effects for collision - angles on the paddle should allow the ball to bounce, as well as doing curve balls etc. I could use ...
3
votes
2answers
201 views

Subdividing a polygon into boxes of varying size

I would like to be pointed to information / resources for creating algorithms like the one illustrated on this blog, which is a subdivision of a polygon (in my case a voronoi cell) into several boxes ...
3
votes
1answer
141 views

Algorithm for approximating sihlouette image as polygon [duplicate]

Possible Duplicate: Is there any heuristic to polygonize a closed 2D raster shape with n triangles? I want to be able to analyze a texture in real time and approximate a polygon to ...
2
votes
3answers
2k views

Mesh with quads to triangle mesh

I want to use Blender for making models yet realize some of the polygons are not triangles but contain quads or more (example: cylinder top and bottom). I could export the the mesh as a basic mesh ...
2
votes
2answers
231 views

Would it be more efficient to handle 2D collision detection with polygons, rather than both squares/polygons?

I'm working on a 2D game engine and I'm trying to get collision detection as efficient as possible. One thing I've noted is that I have a Rectangle Collision collider, a Shape (polygon) collider and a ...
2
votes
3answers
289 views

Polygonal Triangulation - algorithm with O(n log n) complexity

I wish to triangulate a polygon I only have the outline of (p0, p1, p2 ... pn) like described in this question: polygon triangulation algorithm and this webpage: ...
2
votes
1answer
493 views

Maya 2012: Is it possible to convert a single polygon to solid object?

Is it possible to somehow extrude a single polygon into creating a solid object (ex: converting square polygon to cube)?
2
votes
2answers
171 views

How can I move a polygon edge 1 unit away from the center?

Let's say I have a polygon class that is represented by a list of vector classes as vertices, like so: var Vector = function(x, y) { this.x = x; this.y = y; }, Polygon = function(vectors) { ...
2
votes
1answer
651 views

Box2D + Love2D (Lua) - Assertion fail with polygon meshes

When I try to create a triangle collider for my game it sometimes leads to an assertion fail. I use the physics engine that comes with love2d (Box2D). That's the error message that appears when the ...
2
votes
2answers
148 views

What is the purpose of glEdgeFlagv?

I know that what both glEdgeFlagv and glEdgeFlag do is toggle boundary edge status, but my question is why does the v version exist when the documentation specifies that the only difference is that ...
2
votes
1answer
1k views

How can I make Maya export a mesh as double-sided?

I'm exporting from Maya 2009 to OBJ. The mesh I'm exporting has in it's Render Stats "Double Sided" checked, but when the polygon is exported, only a single side is actually exported. What really ...
2
votes
2answers
59 views

How can I test if a point is behind a polygon in 2D?

In order to improve the performance of my visibility graph generator I am trying to figure out the following. Given the image below; is there a way to find out if a point is 'behind' the polygon? For ...
2
votes
2answers
320 views

Farseer Physics: How to create shape from Vertices?

As you can understand from the title, I'm pretty new to game development. I'm doing this for fun. Anyway here's my question. I have this Farseer Physics samples and i've been studying them for a few ...
2
votes
2answers
105 views

Splitting Graph into distinct polygons in O(E) complexity

If you have seen my last question: trapped inside a Graph : Find paths along edges that do not cross any edges How do you split an entire graph into distinct shapes 'trapped' inside the graph(like ...
2
votes
0answers
43 views

How do I convert a partially transparent image into polygons?

I'm using GLEE2D, a level editor allowing me to import images, scale them, rotate them, and position them onto layers and export the data into XML format. However, it does not tell me objects' ...
2
votes
0answers
43 views

Minimum number of vertex moves to un-intersect a polygon with itself [migrated]

In my game, I have n points that form a self-intersecting polygon. The points can be moved by dragging them. How can I form a non-intersecting polygon this way, in the minimum number of moves?
1
vote
1answer
238 views

Use PIX to find model Polygon count in XNA?

I'm using PIX from the DirectX SDK to monitor my XNA application. I want to see the polygon count a model loaded in the application and was told this was information I could get from using PIX. ...
1
vote
1answer
411 views

How can we match polygon data structure with a background image

I am referring to this fireball game. The ball will collide with background, which is in polygon form. I was wondering, how I can match my polygon data structure with the background image. Say, I ...
1
vote
1answer
357 views

2D SAT Collision Detection not working when using certain polygons (With example)

My SAT algorithm falsely reports that collision is occurring when using certain polygons. I believe this happens when using a polygon that does not contain a right angle. Here is a simple diagram of ...
1
vote
1answer
258 views

How to decompose a rectangular shape in a Voronoi diagram, only generating convex shapes?

I think this is a very straighforward question, lets say i have a building in 2D, a rectangle shape. Now i want to decompose that area in a lot of convex shapes, as seen in a voronoi diagram, or ...
1
vote
2answers
850 views

LWJGL Determining whether or not a polygon is on-screen

Not sure whether this is an LWJGL or math question. I want to check whether a shape is on-screen, so that I don't have to render it if it isn't. First of all, is there any simple way to do this that I ...
1
vote
2answers
248 views

Polygons vs sprites rendering performance in Unity for windows phone 8

I'm currently building a windows phone 8 game with unity, having 111 (no more no less) sprites being updated each frames. I have a strong overhead in the profiler (70% to 90% minimum) I tried the ...
1
vote
1answer
119 views

How can I drag a polygon based on a mouse-moved event?

I have drawn a polygon in Java using java.awt.Polygon. I want to move that polygon with the mouse (by dragging it). I know that I have to use mouseDragged method in addMouseMotionListener. That way I ...