# Tagged Questions

In geometry a vertex is a point defining the corners of polygons or intersections of lines. A triangle for example is defined by 3 vertices with lines between them. In 3D-graphical APIs like OpenGL and Direct3D a vertex is a data structure containing information about the positions, normals, colors,...

16k views

### What are normal, tangent and binormal vectors and how are they used?

I would like to find out the following information: What are they? Example usage in game development (the area they are used in) About the following vector types: Normal Tangent Binormal A ...
649 views

### Special relativity shader in GLSL

I'm trying to implement a GLSL shader which helps understanding special relativity Lorentz Transformation. Let's take two axis-aligned inertial observer O and O' . The observer O' is in motion w.r.t ...
2k views

### How does Unity3D lower an imported .obj vertex count?

I have a question regarding how Unity3D handles importing of .obj files. I'm importing this teapot: http://groups.csail.mit.edu/graphics/classes/6.837/F03/models/teapot.obj The number of vertices ...
3k views

### OpenGL Vertex Attributes - Normalisation

Alas, I have searched, and have found no definitive answer. When would you normalize the vertex data in OpenGL using the following command: glVertexAttribPointer(index, size, type, normalize, stride,...
587 views

### Best practices with Vertices in Open GL

What is the best practice in regards to storing vertex data in Open GL? I.e: struct VertexColored { public: GLfloat position[]; GLfloat normal[]; byte colours[]; } ...
1k views

### Geometry Shader not generating geometry for some Vertices

I am playing with a geometry shader and I am wondering why it doesn't generate geometry for each vertex in all meshes? I don't think this is a Cull problem because the same vertices generate ...
352 views

### GLSL vertex shaders with movements vs vertex off the screen

If i have a vertex shader that manage some movements and variations about the position of some vertex in my OpenGL context, OpenGL is smart enough to just run this shader on only the vertex visible on ...
1k views

### What is the purpose of a Direct3D vertex layout?

This tutorial (msdn) gives a description of a vertex layout. This is an example of a input layout: D3D11_INPUT_ELEMENT_DESC layout[] = { { "POSITION", 0, DXGI_FORMAT_R32G32B32_FLOAT, 0, 0, ...
367 views

### How do I simplify terrain with tunnels or overhangs?

I'm attempting to store vertex data in a quadtree with C++, such that far-away vertices can be combined to simplify the object and speed up rendering. This works well with a reasonably flat mesh, but ...
795 views

### Something other than Vertex Welding with Texture Atlas?

What options (in C# with XNA) would there be for texture usage in a procedural generated 3D world made of cubes to increase performance? Yes, it's like Minecraft. I've been doing a texture atlas and ...
395 views

### How do professional games avoid showing pixel seams in adjacent mesh boundaries due to decimal imprecision?

Graphics cards are mathematically imprecise. So when some meshes are joined by their borders, the graphics card often makes mistakes and decides that some pixels at the seam represent neither object, ...
8k views

### Mapping a Vertex Buffer in DirectX11

I have a VertexBuffer that I am remapping on a per frame base for a bunch of quads that are constantly updated, sharing the same material\index buffer but have different width/heights. However, ...
4k views

### calculate new vertex position given a transform matrix?

How can I get the new position of my vertex given a 4x4 transform matrix or simply 9 floats (positionX, positionY, positionZ, rotationH, rotationP, rotationR, scaleX, scaleY, scaleZ)? Usually I can ...
1k views

### Memory allocation strategy for the vertex buffers (DirectX 10/11)

I'm writing a CAD system. I have a 3D scene and there are many different objects (walls, doors, windows and so on). The user can add or delete objects. The question is: How do I keep track of all the ...
712 views

### Spritebatch Vertex shader world matrix change after each draw

I have a spritebatch where I draw some textures transformed in 3d space. The easy way was just Begin with the transformation matrix, draw, and end it right after. But that is silly, so I'm trying ...
847 views

### Using raw vertex information for sprites rather than SpriteBatch in XNA

I have been wondering whether using SpriteBatch is the best option. Obviously for prototyping or small games it works well. However, I've been wanting to apply techniques such as shaders and lighting ...
784 views

### Per-vertex position/normal and per-index texture coordinate

In my game, I have a mesh with a vertex buffer and index buffer up and running. The vertex buffer stores a Vector3 for the position and a Vector2 for the UV coordinate for each vertex. The index ...
612 views

### How can I find the “end” vertices on an open-ended mesh?

I was looking at a video of a system that extrudes meshes along a curve, connecting them end to end but adjusting the vertices for a smooth connection. It does this with a mesh that as far as I know ...
221 views

### 2D Boxes/Vertices merging

I want to optimize my colliders geometry, at the moment is composed by boxes (it's a tile based game) of the same dimensions, i want to remove the inner vertices to have, at the end, only the shell. ...
729 views

### What is the practical use of IBOs / degenerate vertex in OpenGL?

Vertices in 3D models CAN get cut in the process of optimizing 3D geometry, (degenerate vertices) by 3D graphics software (Blender, ...) when exporting because they aren't needed when reusing a vertex ...
128 views

### Most efficient way to get the world position of the 8 vertexes of a Box Collider (C#)

What I am looking for is the most efficient way to get the world position of the 8 vertexes of the Box Collider of a freely rotated Gameobject. I cannot use collider.bounds since object is rotated, ...
136 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 (...
5k views

### Computing pixel's screen position in a vertex shader: right or wrong?

I am building a deferred rendering engine and I have a question. The article I took the sample code from suggested computing screen position of the pixel as follows: VertexShaderFunction() { ... ...
2k views

### DirectX 9 - model rendering from .obj files issues

Well I can clearly tell that what rendered is close to what I wanted, but there seems to be a few problems. The .obj files contained values like "f", "v", "vt". Image Of Problem: http://i49.tinypic....
2k views

### XNA - Update vertices property stored in a VertexBuffer

I've a class that creates a cube using VertexPositionColor and these vertices are stored in a VertexBuffer. Now i would like to dynamically change the color of my vertices. In my class i have a ...
1k views

### Apply Vertex Colors to XNA Spritebatch sprites

I know that you can use custom vertex and pixel shaders using SpriteBatch but I can't figure out how to apply colors to individual vertex points on a sprite generated by spritebatch. All I can do is ...
495 views

### Count number of Vertices in VertexBuffer in XNA 3.1

Where in XNA 4.0 one can go: myVertexBuffer.VertexCount; What is the best way to count the number of vertices in 3.1 for a dynamic buffer (i.e. where I do not know the number of elements that ...
65 views

### Vertex position problem for connected lines

I’m trying to generate a mesh to display connected segments representing street lines in a mini map. I have problem with vertex orientation that my math knowledge has hard time to resolve. Let’s ...
549 views

### Shader that draws just vertex points

The game I am developing is in unity and I want to make a shader which can be put on a mesh that only 'draws' color on each vertex point. I am not proficient with shaders, and out of all my searching ...
156 views

### Surface normal to screen angle

I've been struggling to get this working. I simply wish to take a surface normal and convert it to a screen angle. As an example, assuming we're working with the highlighted surface on the sphere ...
3k views

### How do I morph between meshes that have different vertex counts?

I am using MeshMorpher from the Unify wiki in my Unity project, and I want to be able to transform between arbitrary meshes. This script only works when there are an equal number of vertices between ...
192 views

### Overlapping vertices on sphere?

Iv started up doing some programming in XNA as Iv been doing C# for several years and would like to start do some 3D work with C# and XNA framework. Right now Im trying to build a sphere by code. It ...
6k views

### How to determine counter-clockwise vertex winding

I've been causing myself some confusion lately with regards to vertex winding in a mesh class that i'm writing. Currently, the mesh contains the appropriate structures for: vertices (vector3) ...
459 views

### Can using different vertex-buffers for each vertex-attributes be good in certain scenarios?

Is there scenarios where this is actually good practice? Or does it slow down performance? Example: //Vertex format is: //X, Y, U, V var myXYs:Vector.<Number> = new <Number>[ -1, -1, ...
758 views

### When I select one vertex it selects multiple vertices?

I'm trying to do some kind of a face. When I select a vertex it selects two other vertices. However, when I try to select one of the two other vertices it doesn't select them. I want to move only one ...
86 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 ...
300 views

### Shader and Custom Vertex Format Errors

I am creating an editor of sorts that allow you to create 3D voxel models. I just got started and have ran into a few errors. Here is what it is producing: I think the problem has to do with the ...
2k views

### How does one avoid hundreds of copies into a vertex buffer each frame?

Assume a Direct3D9-based 2D game, high resolution, very busy. Performance critical. A particle system has 2,000 particles. They are scattered throughout the world with only a subset visible on screen ...
150 views

### Why doesn't Array.Copy to mesh.verticies work in Unity?

I am rebuilding a mesh but something seems odd that I have to create a temp array just to hold the verticies rather than copy an array. I'm not using list because this is used frequently and I do not ...
87 views

### OpenGL vertex data per index

Usually, vertex data is assigned to a particular vertex, like this: [data] [vertices] [1.31] -> [1, 13, 5] [84.3] -> [5, 8, 12] [.095] -> [8, 3, 10] Then, you would typically have an ...
133 views

### How can I deal with vertex precision errors between terrain chunks?

I am using OpenGL to render the following scene, using vertex data from one of the map files of a popular MMORPG. The data is chunked and the pictured scene is made up of 256 (16x16) chunks. However ...
182 views

### One or multiple VertexBuffers

I'm currently working on a personal project where I'm trying to load the levels and all of the geometry from the game "Medal of Honor Allied Assault" into my own C# code-base based on SharpDX. I ...
137 views

### Pixelated Normal Generation

I am generating normals for each vertex in a standard 512*512 quad. Yet when I do using the following code: public Vector3f[] normals(Vector3f[] surface){ Vector3f[] normals = new Vector3f[surface....
435 views

### Implementing IVertexType Interface

In XNA, I have created a new VertexType, called it VertexPositionTextureLight which inherts the IVertexType Interface, but apparently I need to implement the member of VertexDeclartion which I cleary ...
196 views

### Point welding on generated terrain

I am converting two 2D images (A Voronoi graph and a Diamond Square noise map) into a 3D object. However when finding the corner points of the Voronoi I am left with gaps, so I thought to drop these ...
411 views

### XNA calculate normals for linesegment

I am quite new to 3D graphical programming and thus far only understand that normal somehow define the direction in which a vertex faces and therefore the direction in which light is reflected. I have ...
1k views

### How do I create a manual object with colors for each vertex?

How do I create a shaded manual object with colours for each vertex? Eg if ogreObj is the Ogre::ManualObject : ogreObj->begin("BaseWhiteNoLighting", Ogre::RenderOperation::OT_TRIANGLE_LIST); ...
330 views

### Disappearring instances of VertexPositionColor using MonoGame

I am a complete beginner in graphics developing with XNA/Monogame. Started my own project using Monogame 3.0 for WinRT. I have this unexplainable issue that some of the vertices disappear while doing ...