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

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4
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1answer
289 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? ...
6
votes
3answers
1k 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 ...
2
votes
2answers
130 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 ...
18
votes
5answers
805 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 ...
3
votes
2answers
640 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 ...
0
votes
1answer
186 views

Scanline filling of polygons that share edges and vertices

In this picture (a perspective projection of an icosahedron), the scanline (red) intersects that vertex at the top. In an icosahedron each edge belongs to two triangles. From edge a, only one triangle ...
2
votes
1answer
2k 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 ...
3
votes
1answer
173 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
344 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: ...
0
votes
5answers
2k views

Polygon count target range for MMO being released in 2 years

What would a realistic poly count target range be for NPC and player models in a 3D MMO that will be released in 2 years? What about poly count target range for the entire camera view (environment, ...
1
vote
1answer
493 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
362 views

Collision within a poly

For an html5 engine I'm making, for speed I'm using a path poly. I'm having trouble trying to find ways to get collision with the walls of the poly. To make it simple I just have a vector for the ...
0
votes
1answer
217 views

How can I locate empty space next to polygon regions?

Let's say I have the following area in a top-down map: The circle is the player, the black square is an obstacle, and the grey polygons with red borders are walk-able areas that will be used as a ...
2
votes
2answers
208 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) { ...
3
votes
3answers
452 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 ...
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 ...
1
vote
1answer
346 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 ...
6
votes
1answer
690 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). ...
5
votes
1answer
563 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
1answer
524 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 ...
12
votes
1answer
4k 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 ...
2
votes
1answer
798 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
1answer
639 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)?
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 ...
7
votes
2answers
3k 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 ...
7
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 = ...
7
votes
3answers
756 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 ...
1
vote
1answer
249 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. ...
2
votes
2answers
159 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 ...
0
votes
1answer
807 views

How to render images/textures in shape/polygon form?

I'm working with SFML right now, and upon finishing the tutorials I still do not know how to give a shape a texture or image -- not just a solid color/outline. The only thing I know can take an ...
1
vote
1answer
426 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
2answers
1k 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 ...
8
votes
2answers
2k 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 ...
5
votes
1answer
231 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
5answers
8k 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 ...
3
votes
1answer
641 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 ...