# Tagged Questions

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

51 views

### Triangles go missing as Z changes

I'm rendering a height map using shader-based OpenGL (3.3 to be precise). The height map data is from a grayscale bitmap (2D array of bytes). The dimension of the bitmap is 256 x 256. With this data, ...
128 views

### OpenGL: I only see one square instead of a cube / giving information to vertex shader

I am new to OpenGL and tried to follow this tutorial. I use C# and OpenTK. So I translate the C++ Code from the Tutorial: My C#-Code: /* Hintergrundfarbe */ ...
39 views

### Create dynamic cities of perspective angle x with least amount of tiles

I found you can create unique building sizes with perspective with six tiles using parallel projection, whose angles are always 45 degrees... this allows you to connect to the next tile without issue: ...
76 views

### Why does this code to render a triangle in SlimDX only show a black screen?

Here is the code: var elements = new VertexElement[] { new VertexElement(0,0,DeclarationType.Float3,DeclarationMethod.Default, ...
72 views

### Generate 2D Triangular Mesh from Vertices on a Map

Given a map of vertices {(x1,y1), (x2,y2), ... (xn,yn)}, how can I generate a 2D triangular mesh covering all vertices, and where the area of all triangles completely covers the map? The triangular ...
181 views

### OpenGL drawing, breaking down triangles

if I want to use no textures in a game (i.e png's), would I just break down my drawing into triangles and combine them the way I want? I found this in Google Images.
93 views

### Given face normal and vertices of a triangle, how to find the acyclic order of vertices?

I'm in the process of constructing a custom 3D triangle mesh. I found the vertices of the triangle in the 3D space and it's face normal. How do I find the acyclic order of vertices? If I draw the ...
107 views

### How to draw non-triangulated mesh?

I am working with DirectX (C#/C++). I am wondering is it possible to do not triangulate meshes and what the difference between cases (in loading and rendering code)? If so, how to do this? I know ...
624 views

### Triangle-triangle continuous collision detection

I am making a 3D game engine and I use continuous collision detection. I am using Sphere-Trees to cull primitive collision checks to a minimum. However, I'd like to perform continuous ...
165 views

### Directional, Triangular Collision Detection in Pygame [duplicate]

I am trying to create a game in Pygame, with Python 3, and am trying to figure out an algorithm that will tell me which direction a rectangle is colliding with a rectangle, so that I can push it back ...
223 views

### How does the Direct3D 9 rasterizer determine triangle coverage?

I'm working on a software rasterizer to use in my project. I have implemented one that works well, however, often my rasterizer under or over estimates triangle coverage. I need perfect emulation of ...
129 views

### Angle between two planes

I have two triangles in 3d space which share 1 edge and I would like to determine if the angle between their normal vectors is "uphill" or "downhill". In other words, if you set one flat, would the ...
734 views

I'm curious to know which is better for games? Quads or Triangles? Wouldn't quads be better for rendering performances and smoothing out tessellation?
134 views

### XNA Calculate two points of triangle with given Z

I want to calculate the two points of a 3D triangle that have a specified Z coordinate. I guess the way to do this would be to somehow create a plane which is perfectly flat with my given Z coordinate ...
59 views

### XNA inverted matrix acting strange

First of all, I am trying to calculate the two points of a triangle that have a given z position. I have figured out what I think to be quite a good method. First of all I move the triangle to be ...
1k views

### How do I find the circumcenter of a triangle in 3D?

I want to find the circumcenter of a triangle. Wolfram only shows how to find the circumcircle of a triangle in R2. How can I find the circumcenter of a triangle in R3?
146 views

### SAT test for Triangle - convex hull

I'm having real trouble resolving this issue with triangle-convex hull SAT test intersection. The problem is as follows: Misses are detected accurately enough: Clear miss I have not found a ...
158 views

### Efficient way to draw multiple separated quads

Let's assume I want to draw several separated (possibly textured) quads in Direct3D 9, each consisting of two triangles: How should I draw these for maximum performance, i.e. which of the following ...
144 views

### Moller Tri Tri intersection

I'm done implementing Moller's tri-tri intersection routine. It gives you the location of where each triangle edge intersects the line of intersection between the 2 triangle planes: Really you get ...
274 views

### Is there a game not using meshes for models? [closed]

Traditionally, models consist of lots of vertices connected by triangles. That forces the use of a high amount of vertices for detailed organic shapes or makes models kind of blocky. Even though ...
107 views

### XNA 4.0 thick triangle strip to fix aliasing issues upon rotation

My triangle strip based lines are disappearing intermittently when I rotate my camera around the X axis. I was advised that this is due to aliasing issues and that "At a certain angle when its edge ...
214 views

### How do I implement my old OpenGL-based gfx_render_triangle_list using DX11?

I am working at a game that has lots of procedural content. I had built a game engine using OpenGL that handles everything needed for creating a basic 2D game, sprites, primitives, blending, polygons ...
2k views

### Unity's “Stats” window displays bizzare number of triangles and vertices

In my Unity scene I have: 7-8 Barrels (with lids) each at about 2-400 triangles. 4 planes, each at at the very most 200 triangles camera, 3 lights, a FPS controller When I turn on the "Status" ...
216 views

### Optimizing models & improving performance

I've created a map editor for a game I've been developing. The maps (planets) are made using a form of meta ball editing. Basically, in the end the Marching Cubes algorithm is used to get my final ...
750 views

### How to draw a trapezoid in OpenGL?

The question seems easy, but you simply change vertex positions to match the corners of a trapezoid but it simply fails. I've tried scaling top and bottom edges like this : but when I apply my ...
4k 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 ...
171 views

### Point[] and Tri not “could not be found”

Hi I'm trying to learn how to load a .obj file using OpenTK in windows Forms. I have seen a lot of examples out there, but I do see almost everyone uses List, and Point[]. Code example show these ...
264 views

### Texturize a shape of multiple triangles in 2D

This is an example of a shape consisting of multiple points, triangles and eventually a shape: Red Dots = Vector3 (X, Y, Z) or Vector2 (X, Y) If I have a Texture of a certain size, how do I ...
474 views

### Fast software color interpolating triangle rasterization technique

I'm implementing a software renderer with this rasterization method, however, I was wondering if there is a possibility to improve it, or if there exists an alternative technique that is much faster. ...
259 views

### Software rendering 3d triangles in the proper order

I'm implementing a basic 3d rendering engine in software (for education purposes, please don't mention to use an API). When I project a triangle from 3d to 2d coordinates, I draw the triangle. ...
196 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): ...
331 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: ...
2k 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?
327 views

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 ...
239 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 ...
494 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 ...
495 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 ...
150 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 ...
267 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'; ...
781 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 ...
183 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 ...
555 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 ...
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 ...
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 ...
840 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, ...
300 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 ...
579 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 ...
192 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 ...