Using sketch up data to render a cube in Xcode

Question

I am playing around with the OpenGL ES template in Xcode 4.5. I draw a cube in Google Sketchup and exported into collada. I copied the vertex and normal data into the open gl template in Xcode as below:

GLfloat gCubeVertexData[] =
{
    // Data layout for each line below is:
    // positionX, positionY, positionZ,     normalX, normalY, normalZ,
//    0.5f, -0.5f, -0.5f,        1.0f, 0.0f, 0.0f,
//    0.5f, 0.5f, -0.5f,         1.0f, 0.0f, 0.0f,
//    0.5f, -0.5f, 0.5f,         1.0f, 0.0f, 0.0f,
//    0.5f, -0.5f, 0.5f,         1.0f, 0.0f, 0.0f,
//    0.5f, 0.5f, -0.5f,         1.0f, 0.0f, 0.0f,
//    0.5f, 0.5f, 0.5f,          1.0f, 0.0f, 0.0f,
//    
//    0.5f, 0.5f, -0.5f,         0.0f, 1.0f, 0.0f,
//    -0.5f, 0.5f, -0.5f,        0.0f, 1.0f, 0.0f,
//    0.5f, 0.5f, 0.5f,          0.0f, 1.0f, 0.0f,
//    0.5f, 0.5f, 0.5f,          0.0f, 1.0f, 0.0f,
//    -0.5f, 0.5f, -0.5f,        0.0f, 1.0f, 0.0f,
//    -0.5f, 0.5f, 0.5f,         0.0f, 1.0f, 0.0f,
//    
//    -0.5f, 0.5f, -0.5f,        -1.0f, 0.0f, 0.0f,
//    -0.5f, -0.5f, -0.5f,       -1.0f, 0.0f, 0.0f,
//    -0.5f, 0.5f, 0.5f,         -1.0f, 0.0f, 0.0f,
//    -0.5f, 0.5f, 0.5f,         -1.0f, 0.0f, 0.0f,
//    -0.5f, -0.5f, -0.5f,       -1.0f, 0.0f, 0.0f,
//    -0.5f, -0.5f, 0.5f,        -1.0f, 0.0f, 0.0f,
//    
//    -0.5f, -0.5f, -0.5f,       0.0f, -1.0f, 0.0f,
//    0.5f, -0.5f, -0.5f,        0.0f, -1.0f, 0.0f,
//    -0.5f, -0.5f, 0.5f,        0.0f, -1.0f, 0.0f,
//    -0.5f, -0.5f, 0.5f,        0.0f, -1.0f, 0.0f,
//    0.5f, -0.5f, -0.5f,        0.0f, -1.0f, 0.0f,
//    0.5f, -0.5f, 0.5f,         0.0f, -1.0f, 0.0f,
//    
//    0.5f, 0.5f, 0.5f,          0.0f, 0.0f, 1.0f,
//    -0.5f, 0.5f, 0.5f,         0.0f, 0.0f, 1.0f,
//    0.5f, -0.5f, 0.5f,         0.0f, 0.0f, 1.0f,
//    0.5f, -0.5f, 0.5f,         0.0f, 0.0f, 1.0f,
//    -0.5f, 0.5f, 0.5f,         0.0f, 0.0f, 1.0f,
//    -0.5f, -0.5f, 0.5f,        0.0f, 0.0f, 1.0f,
//    
//    0.5f, -0.5f, -0.5f,        0.0f, 0.0f, -1.0f,
//    -0.5f, -0.5f, -0.5f,       0.0f, 0.0f, -1.0f,
//    0.5f, 0.5f, -0.5f,         0.0f, 0.0f, -1.0f,
//    0.5f, 0.5f, -0.5f,         0.0f, 0.0f, -1.0f,
//    -0.5f, -0.5f, -0.5f,       0.0f, 0.0f, -1.0f,
//    -0.5f, 0.5f, -0.5f,        0.0f, 0.0f, -1.0f


    9.8425197/9.8425197, 9.8425197/9.8425197, 0.0000000/9.8425197,    0.0000000, 0.0000000, -1.0000000,
    0.0000000/9.8425197, 0.0000000/9.8425197, 0.0000000/9.8425197,    0.0000000, 0.0000000, -1.0000000,
    0.0000000/9.8425197, 9.8425197/9.8425197, 0.0000000/9.8425197,    0.0000000, 0.0000000, -1.0000000,
    9.8425197/9.8425197, 0.0000000/9.8425197, 0.0000000/9.8425197,    0.0000000, 0.0000000, -1.0000000,
    0.0000000/9.8425197, 9.8425197/9.8425197, 8.2677165/9.8425197,    -1.0000000, 0.0000000, 0.0000000,
    0.0000000/9.8425197, 0.0000000/9.8425197, 0.0000000/9.8425197,    -1.0000000, 0.0000000, 0.0000000,

    0.0000000/9.8425197, 0.0000000/9.8425197, 8.2677165/9.8425197,    -1.0000000, 0.0000000, 0.0000000,
    0.0000000/9.8425197, 9.8425197/9.8425197, 0.0000000/9.8425197,    -1.0000000, 0.0000000, 0.0000000,
    0.0000000/9.8425197, 9.8425197/9.8425197, 8.2677165/9.8425197,    -0.0000000, 1.0000000, 0.0000000,
    9.8425197/9.8425197, 9.8425197/9.8425197, 0.0000000/9.8425197,    -0.0000000, 1.0000000, 0.0000000,
    0.0000000/9.8425197, 9.8425197/9.8425197, 0.0000000/9.8425197,    -0.0000000, 1.0000000, 0.0000000,
    9.8425197/9.8425197, 9.8425197/9.8425197, 8.2677165/9.8425197,    -0.0000000, 1.0000000, 0.0000000,

    9.8425197/9.8425197, 9.8425197/9.8425197, 0.0000000/9.8425197,    1.0000000, 0.0000000, 0.0000000,
    9.8425197/9.8425197, 0.0000000/9.8425197, 8.2677165/9.8425197,    1.0000000, 0.0000000, 0.0000000,
    9.8425197/9.8425197, 0.0000000/9.8425197, 0.0000000/9.8425197,    1.0000000, 0.0000000, 0.0000000,
    9.8425197/9.8425197, 9.8425197/9.8425197, 8.2677165/9.8425197,    1.0000000, 0.0000000, 0.0000000,
    9.8425197/9.8425197, 0.0000000/9.8425197, 8.2677165/9.8425197,    -0.0000000, -1.0000000, -0.0000000,
    0.0000000/9.8425197, 0.0000000/9.8425197, 0.0000000/9.8425197,    -0.0000000, -1.0000000, -0.0000000,

    9.8425197/9.8425197, 0.0000000/9.8425197, 0.0000000/9.8425197,    -0.0000000, -1.0000000, -0.0000000,
    0.0000000/9.8425197, 0.0000000/9.8425197, 8.2677165/9.8425197,    -0.0000000, -1.0000000, -0.0000000,
    9.8425197/9.8425197, 0.0000000/9.8425197, 8.2677165/9.8425197,    0.0000000, 0.0000000, 1.0000000,
    0.0000000/9.8425197, 9.8425197/9.8425197, 8.2677165/9.8425197,    0.0000000, 0.0000000, 1.0000000,
    0.0000000/9.8425197, 0.0000000/9.8425197, 8.2677165/9.8425197,    0.0000000, 0.0000000, 1.0000000,
    9.8425197/9.8425197, 9.8425197/9.8425197, 8.2677165/9.8425197,    0.0000000, 0.0000000, 1.0000000
};

enter image description here

When I run, I have the rendered cube below, so something is not right.

=======

It looks like if I am using normals, I don't need to provide the indices to render a 3D object. But in my case there seems to be something out of order either in the vertex data or normal... Does any one know how in collada this two data are arranged? I read through the documentation but I couldn't find an answer... Thanks

If I am using normals I don't need the indices do I? because the iOS OpenGL template code doesn't have indices, it has normals though. — Pupillam, Sep 30 '12 at 07:43
Yes, you do. The only time you don't need indices is if they are consecutive, e.g. 0-N. even then, they just get generated — jterrace, Sep 30 '12 at 13:16

Using sketch up data to render a cube in Xcode

0 Answers0