Hi there! I''m switching from D3D to OpenGL... and it''s painful!! Well... the problem is that I define a vertex structure like this: struct CUSTOMVERTEX { GLfloat x, y, z; // Position GLfloat nx, ny, nz; // Normal GLfloat tu, tv; // Texture coordinates }; and init the indices for my mesh: GLushort indices[] = { 0+0, 0+1, 0+2, 0+2, 0+3, 0+0, 4+0, 4+1, 4+2, 4+2, 4+3, 4+0, 8+0, 8+1, 8+2, 8+2, 8+3, 8+0, 12+0, 12+1, 12+2, 12+2, 12+3, 12+0, 16+0, 16+1, 16+2, 16+2, 16+3, 16+0, 20+0, 20+1, 20+2, 20+2, 20+3, 20+0 }; Then, I init some shape (a cube) this way: void Create_Cube() { // Define normals VECTOR n0( 0.0f, 1.0f, 0.0f ); // Top face VECTOR n1( 0.0f, -1.0f, 0.0f ); // Bottom face VECTOR n2( -1.0f, 0.0f, 0.0f ); // Left face VECTOR n3( 1.0f, 0.0f, 0.0f ); // Right face VECTOR n4( 0.0f, 0.0f, -1.0f ); // Back face VECTOR n5( 0.0f, 0.0f, 1.0f ); // Front face // Top face vertices[0] = Init_Vertex( VECTOR(-1.0f, 1.0f, 1.0f), n0, 0.0, 1.0); vertices[1] = Init_Vertex( VECTOR(-1.0f, 1.0f, -1.0f), n0, 0.0, 0.0); vertices[2] = Init_Vertex( VECTOR(1.0f, 1.0f, -1.0f), n0, 1.0, 0.0); vertices[3] = Init_Vertex( VECTOR(1.0f, 1.0f, 1.0f), n0, 1.0, 1.0); // Bottom face vertices[4] = Init_Vertex( VECTOR(-1.0f, -1.0f, -1.0f), n1, 1.0, 0.0); vertices[5] = Init_Vertex( VECTOR(-1.0f, -1.0f, 1.0f), n1, 1.0, 1.0); vertices[6] = Init_Vertex( VECTOR(1.0f, -1.0f, 1.0f), n1, 0.0, 1.0); vertices[7] = Init_Vertex( VECTOR(1.0f, -1.0f, -1.0f), n1, 0.0, 0.0); // Left face vertices[8] = Init_Vertex( VECTOR(-1.0f, -1.0f, -1.0f), n2, 0.0, 1.0); vertices[9] = Init_Vertex( VECTOR(-1.0f, 1.0f, -1.0f), n2, 0.0, 0.0); vertices[10] = Init_Vertex( VECTOR(-1.0f, 1.0f, 1.0f), n2, 1.0, 0.0); vertices[11] = Init_Vertex( VECTOR(-1.0f, -1.0f, 1.0f), n2, 1.0, 1.0); // Right face vertices[12] = Init_Vertex( VECTOR(1.0f, -1.0f, 1.0f), n3, -1.0, 0.0); vertices[13] = Init_Vertex( VECTOR(1.0f, 1.0f, 1.0f), n3, -1.0, -1.0); vertices[14] = Init_Vertex( VECTOR(1.0f, 1.0f, -1.0f), n3, 0.0, -1.0); vertices[15] = Init_Vertex( VECTOR(1.0f, -1.0f, -1.0f), n3, 0.0, 0.0); // Back face vertices[16] = Init_Vertex( VECTOR(1.0f, -1.0f, -1.0f), n4, 0.0, 1.0); vertices[17] = Init_Vertex( VECTOR(1.0f, 1.0f, -1.0f), n4, 0.0, 0.0); vertices[18] = Init_Vertex( VECTOR(-1.0f, 1.0f, -1.0f), n4, 1.0, 0.0); vertices[19] = Init_Vertex( VECTOR(-1.0f, -1.0f, -1.0f), n4, 1.0, 1.0); // Front face vertices[20] = Init_Vertex( VECTOR(-1.0f, -1.0f, 1.0f), n5, 0.0, 1.0); vertices[21] = Init_Vertex( VECTOR(-1.0f, 1.0f, 1.0f), n5, 0.0, 0.0); vertices[22] = Init_Vertex( VECTOR(1.0f, 1.0f, 1.0f), n5, 1.0, 0.0); vertices[23] = Init_Vertex( VECTOR(1.0f, -1.0f, 1.0f), n5, 1.0, 1.0); } By the way, VECTOR is a simple structure: typedef struct _VECTOR { GLfloat x, y, z; } VECTOR; And Init_Vertex returns a valid CUSTOMVERTEX structure. Now, how can I use Indexed Vertex Arrays with this data? I tryed the following: // Enable and specify the vertex array glEnableClientState(GL_VERTEX_ARRAY); glVertexPointer(3, GL_FLOAT, sizeof(CUSTOMVERTEX), vertices); // Using Drawarrays glDrawElements(GL_TRIANGLES, 24, GL_UNSIGNED_SHORT, indices); ... but failed. Please give me a hand. I really need it. Thanks in advance, and sorry for the long post. Cristián Ramírez (gameovercl) ICQ #38991565 Viña del Mar CHILE

Doh! It was so easy! I solved my problem.
If anyone is interested on the solution, e-mail me at ramirez2@entelchile.net

Hummm... sometimes is hard to think in OpenGL terms when you worked with D3D for years...

Cristián Ramírez (gameovercl)
ICQ #38991565
Viña del Mar
CHILE

Hey,

Great that you solved the problem
You said that switching from d3d to openGL is painful. What is exactly the hardest part in it, if I may ask?

-tee

Well, my friend, OpenGL is far easier than Direct3D (any version of it). But switching from a left-handed coordinate system to a right-handed coordinate system is a pain (it''s not that easy to only change the sign of the Z coordinate).
On the other side, DX offers the D3DX library, which supports loading differents file formats, does math calculations (dot product, cross product, matrix algebra, etc.). So, without D3DX, you start to feel a bit without a great tool :=)
On the other side, D3D is much "C++ friendly" - I mean - it was made thinking on a C++ basis. OpenGL - trying to be portable - is like "another" language, if you know what I mean. One example is the idea of the "state machine", which does not exist on D3D; the bahavior in this sense on D3D is more C++ oriented than OpenGL.
Anyway, switching to OpenGL is a nice trip

If you want to port your code to D3D, feel free to e-mail me. So, you will not suffer as I am suffering now (LOL).


Cristián Ramírez (gameovercl)
ICQ #38991565
Viña del Mar
CHILE