Polygons with three corners or vertices and three sides or edges which are line segments.

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2
votes
2answers
227 views

Drawing multiple triangles at once isn't working

I'm trying to draw multiple triangles at once to make up a "shape". I have a class that has an array of VertexPositionColor, an array of Indexes (rendered by this Triangulation class): http://www....
2
votes
3answers
494 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: http://cgm.cs.mcgill.ca/~godfried/...
12
votes
3answers
3k views

Why are triangle fans not supported in Direct3D 10 or later?

http://msdn.microsoft.com/en-us/library/windows/desktop/bb206271(v=vs.85).aspx Why? Are there inherent drawbacks to working with triangle fans?
7
votes
2answers
420 views

Must I worry about quad-based rendering in real world scenarios?

Most of the time in the first chapters of a random book about rasterization and rendering techniques, I find some phrases about a triangle-based rendering system and a quad-based one. I have never ...
4
votes
1answer
278 views

Create shape from points / lines in editor and mathematically calculate nearest points within shape

If I want an editor that accepts "points" of a minimum of three (a triangle) and I just add some points first, like this: how can I mathematically connect these corners (points) into an object of ...
1
vote
1answer
701 views

Why is my mesh generation algorithm not working properly?

I am trying to generate a grid in OpenGL ES, using known methods for triangle strips and stitching as shown in: this post and this post The code below, generates the vertices for a 4x4 grid with a ...
0
votes
4answers
785 views

Missing triangles in model

I am having an issue where triangles in a model aren't being shown. The left is wireframe, the right is the finished image. For some reason a bunch of the triangles aren't being shown. The project ...
1
vote
1answer
192 views

Drawing texture does not work anymore with a small amount of triangles

When i draw lines, the vertices are well connected. But when i draw the texture inside the triangles, it only works with i<4 in the for loop, otherwise with i<5 for example, there is a ...
4
votes
2answers
275 views

What does “kTriangles/s” mean in hardware graphics benchmark reports?

I've looked around and found several sites offering benchmarking statistics for mobile platforms and I've been seeing the unit of measure as "kTriangles/s". Originally I misread this, missing the 'k'; ...
1
vote
1answer
1k views

Opengl create tunnel TRIANGLES and texture coords on a 3d path

I have a path, lets say a bezier, or a circle. I d like to make a continously 3d cylinder (tunnel) on it (R=0.5f) How can I calculate tha TRIangles (TRIANGLE_STRIP) coordinate, and the texture ...
3
votes
4answers
251 views

Ray Triangle Intersection issue

I'm trying to perform ray triangle intersection on a mesh made of triangles. The below code seems to work fine but only about 50% of the time. The ray often gets into positions where no intersection ...
1
vote
1answer
819 views

What are the basics of 3D triangle/quad sorting?

I am really curious how any 3D engine or even the GPU sorts triangles and quads. Are they basically taking a "center" point of a particular triangle/quad/poly and then calculate a distance from a ...
3
votes
1answer
2k views

How do you split indices and vertices if their quantity goes over the limit?

I try to draw a flat surface of 500x500 squares which are built out of four vertices by two triangles. There are 1,000,000 vertices and 1,500,000 indices. The Reach profile of xna, limits primitives ...
3
votes
2answers
2k views

How does a BSP tree work for Z sorting?

I'm developing a 3D engine in software, and so I must compute Z sorting manually. I'm currently using the painters algorithm to sort triangles and then drawing them back-to-front. This causes ...
2
votes
1answer
1k views

Drawing a textured triangle with CPU instead of GPU

I understand the benefits of GPU rendering and such, but for a certain limited application I need to render textured triangles purely using CPU. I've built a 3D engine capable of object handling, ...
2
votes
1answer
333 views

Dynamically creating astar node map by triangular polygonal map

My game's map format uses a bunch of triangles to make up the platforms and terrain in 2d. Right now I can set up a 2d array of nodes for the astar algorithm that basically is a bunch of rectangles ...
3
votes
4answers
680 views

How to draw a line of a given length towards a given object?

I wanna draw a line between two moving objects I can't use: cDrawLine(startPointCG, endPointCG); because the line must have a length. So I'm trying to measure the angle between those two points ...
1
vote
1answer
207 views

How to optimize primitives in SecondLife/Opensim?

SecondLife/Opensim uses Primitives to construct models. How it works in details is explained here. Now I have many triangles which link together. Is there any way to make them into one prim, thus ...
6
votes
2answers
3k views

How do you triangulate an arbitrary polygon?

I need to triangulate a polygon for rendering in opengl es on android ( no glu triangulation available) Is there an already known algorithm for polygon triangulation? The polygon can be convex or ...
40
votes
8answers
17k views

Why do game engines convert models to triangles compared to keeping it as four side polygon

I've worked using maya for animation and more film orientated projects however I am also focusing on my studies on video game development (eventually want to be either programmer or some sort of TD ...
4
votes
3answers
6k views

Triangle - Rectangle Intersection in 2D

I had previously asked this for 3D but now I changed my strategy and would like to do the intersection in 2D. The Rectangle is axis aligned and will always be in a fixed position, and has a constant ...
4
votes
2answers
3k views

Triangle-Plane intersection in 3D space

I would like to clip a triangle if its bounds lie partially out of a cube for this I guess I would need some kind of Triangle Plane intersection code, I'm not well versed with math but I do have the ...
10
votes
1answer
1k views

Triangulation A* (TA*) pathfinding algorithm

I need help understanding the Triangle A* (TA*) algorithm that is described by Demyen in his paper Efficient Triangulation-Based Pathfinding, on pages 76-81. He describes how to adapt the regular A* ...
3
votes
1answer
1k views

Ray-plane intersection to find the Z of the intersecting point

I have a rectangle in 3d space (p1, p2, p3, p4) and when the mouse rolls over it I need to calculate the exact Z of the point on the rect, given the mouse coordinates (x, y). Would a Ray-plane ...