# Tagged Questions

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

127 views

### Make a triangular mesh from of a map defined by points that follow the coast lines

I have a set of points which follow the coast lines of a world map. I would like to somehow triangulate so that I can render the continents filled in. The points seam to be in order so that if you ...
31 views

### Drawing a gradient triangle with depth in mind [closed]

I'm writing a software 3D rasterizer. I managed to get a gradient triangle to work in it: And a triangle with z-depth shown on it: But, how do I blend these two? So that I draw a gradient ...
83 views

### If a 3d surface is occluded by another 3d surface, does this have any effect on the performance and rendering speed?

We have a 3D character who is wearing a Gauntlet on his forearm and visibility of which can be turned on and off. Would it be better to create 2 versions of arm, one without extra triangles that are ...
125 views

### How to rotate a triangle towards the point in Qt?

I have an issue with items rotating. I have a point and a triangle which needs to be rotated with its apex point towards the taregt point. The right side of the picture represents how it is should to ...
94 views

### How to reproduce this triangle filling scanline effect using a shader?

I'm writing a renderer for an old DOS game were 3D polygons were rendered in software. I'd like to simulate, using a shader, the following material/effect, used for filling a triangle : The fist ...
103 views

### The better performance in occlusion culling, plane or quad?

In the above picture, when the left camera shows two small parts of the quad, all of that is rendered (it can be a very large quad). But in the right one only two small parts of it is rendered. ...
32 views

### Triangle mesh - curvature

I have a triangle mesh with normals. What algorithm is considered to be "standard" with best possible quality for triangle mesh curvature computation (mean and gauss). Something like for normal ...
118 views

### Algorithm for triangle picking?

So i found out that i need a triangle picking algorithm, i need to see if my mouse is over the triangle. I've heard what color picking is, but it would pretty much just drop the performance twice ...
200 views

### Calculate the slope of a 3D triangle?

I have lots of triangles in 3D space. How do I determine the slope/angle of these triangles with respect to a fixed ground plane? I need pseudo code examples at the very least. Thanks!  Based ...
32 views

### Strange offset when accessing pixels from an SDL surface

I am using a routine to map a triangle from one surface to another. The problem is that the function below chooses the correct pixel to draw on the destination surface, but the pixel selected from the ...
128 views

### Should a mesh consist of triangles or quads?

Currently I am a bit puzzled. I am writing my master thesis about procedural mesh and texture generation and for that I am writing a Blender Add-On to generate low poly planets with physical ...
286 views

### Generating mesh along path

I'm currently trying to generate a path along an array of points(Vector3) This is the result i'm currently getting The dark gray points are the given path The red points are the generated verticies ...
29 views

### How to calculate per vertex normals? (OpenGL) [duplicate]

I am really confused and quite much thinking about how to do that? Cross product and then, normalizing is not working for me. Or perhaps, I take them all wrong. Well, please explain me that while ...
150 views

### Does triangle-plane clipping in 3D always produce a triangle?

When you clip a triangle against a plane, will you always get a triangle out? Are there perhaps cases where you don't get a triangle out of clipping it against a plane?
121 views

### Libgdx Drawing a triangle cannot resolve method “render ”

I am looking to draw a triangle. I found a lot of code such as : https://github.com/libgdx/libgdx/wiki/My-First-Triangle-%28Example%29 The code I found are old I think; if I use ...
82 views

### Good way to support multiple types of triangles? (C# XNA)

[this question is somewhat long. here's my question in a nutshell] I want to use multiple types of Vertex data types for my triangle, interchangeably. So if I have a generic type T private void ...
491 views

I have about 2+ years of experience in computer gaming development and I just started writing my own shaders to help me utilize performance. I have this problem that I'm trying to work around but ...
705 views

### Fastest way to find closest triangle of mesh from specified point

I have two triangle meshes (let me call them A and B). The meshes may be really big (10.000 - 100.000 polygons). I want to find for every point in A the closest triangle from mesh B. Is there fast ...
863 views

### Triangle-Triangle Intersection Code

Does anyone have experience implementing this triangle-triangle intersection code that I found online? I don't understand it. I made a post on Stack Overflow about this and got the advice that: ...
815 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, ...
3k 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?
362 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 */ ...
102 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: ...
354 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, ...
166 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 ...
335 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.
268 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 ...
203 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 ...
2k 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 ...
7k 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 ...
363 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 ...
519 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 ...
332 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 ...
2k 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?
159 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 ...
232 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 ...
232 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 ...
307 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 ...
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 ...
305 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 ...
137 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 ...
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, ...
239 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 ...
16k 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 ...
4k 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" ...
358 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 ...
1k 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 ...
205 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 ...