Importing and Displaying .fbx files in OpenGl

Question

I have been trying to import and display an fbx file using the `FBX SDK.Untill`. I managed to load in the file, but I got stuck at the part where I have to display it. The questions: - What exactly are those indices? - How should I display the vertices? Here is the class that I made: `3dModelBasicStructs.h` ``` struct vertex { float x,y,z; }; struct texturecoords { float a,b; }; struct poligon { int a,b,c; }; ``` `Model.h` ``` #ifndef MODEL_H #define MODEL_H #define FBXSDK_NEW_API #define MAX_VERTICES 80000 #define MAX_POLIGONS 80000 #include #include "3dModelBasicStructs.h" #include #include using namespace std; class Model { public: Model(char*); ~Model(); void ShowDetails(); char* GetModelName(); void SetModelName( char* ); void GetFbxInfo( FbxNode* ); void RenderModel(); void InitializeVertexBuffer( vertex* ); private: char Name[25]; vertex vertices[MAX_VERTICES]; poligon poligons[MAX_POLIGONS]; int *indices; int numIndices; int numVertices; }; #e…

Accepted Answer

2) How should I display the vertices?

Questions like these indicate, that you should work through some OpenGL tutorials. Those are the basics and you need to know them.

This is a good start regarding your problem, but you'll need to work through the whole tutorial http://opengl.datenwolf.net/gltut/html/Basics/Tut01%20Following%20the%20Data.html

1) What exactly are those indices ?

You have a list of vertices. The index of a vertex is the position at which it is in that list. You can draw vertex arrays by its indices using `glDrawElements`

Update due to comment

Say you have a cube with shared vertices (uncommon in OpenGL, but I'm too lazy for writing down 24 vertices).

I have them in my program in an array, that forms a list of their positions. You load them from a file, I'm writing them a C array:

```
GLfloat vertices[3][] = {
    {-1,-1, 1},
    { 1,-1, 1},
    { 1, 1, 1},
    {-1, 1, 1},
    {-1,-1,-1},
    { 1,-1,-1},
    { 1, 1,-1},
    {-1, 1,-1},
};
```

This gives the vertices indices (position in the array), in the picture it looks like

To draw a cube we have to tell OpenGL in which vertices, in which order make a face. So let's have a look at the faces:

We're going to build that cube out of triangles. 3 consecutive indices make up a triangle. For the cube this is

```
GLuint face_indices[3][] = {
    {0,1,2},{2,3,0},
    {1,5,6},{6,2,1},
    {5,4,7},{7,6,5},
    {4,0,3},{3,7,4},
    {3,2,6},{6,7,2},
    {4,5,0},{1,0,5}
};
```

You can draw this then by pointing OpenGL to the vertex array

```
glVertexPointer(3, GL_FLOAT, 0, &vertices[0][0]);
```

and issuing a batches call on the array with vertices. There are 6*2 = 12 triangles, each triangle consisting of 3 vertices, which makes a list of 36 indices.

```
glDrawElements(GL_TRIANGLES, 36, GL_UNSIGNED_INT, &face_indices[0][0]);
```

Importing and Displaying .fbx files in OpenGl

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