How to load 3D models in OpenGL C++?

Question

I am trying to load 3D models. How do I to read the data in the model file?

For an example, this is the data:

VERTICES
80 21 32
32 34 17
14 93 56
33 54 87
MODEL_SCALE 5

I know the data in 3D models is not like this, but how will I read the 'vertex data' and the 'model scale amount'?

Solution

OpenGL doesn't do this for you. You should write your own parser, store the readed datas into your defined data structures and use OpenGL primitives to render them.

Here's a nice tutorial.

Comments

[CppOgl]

Yes but how will I read the data? What I want to do is read the data of the file and draw vertices on them.

[user786653]

It looks like milkshape is a binary format, which I'm not sure is applicable for OP as it looks like he's showing an example of a text format.

[CppOgl]

Hmm... seems quite helpful. But there is a way reading words with string.h and other stuff like that, right? I'll try to use that too. Anyway, thanks!

[datenwolf]

@CppOgl: FILE *filp = fopen(filename, "r"); fread(...), etc. Or in C++ using ifstream. This not an OpenGL question then, but a generic "how do I read a file" question.

[Heisenbug]

@user786653 : yes you are right. But like datenwolf pointed out, this is not an opengl question. The linked tutorial illustrate some basic operation and datastrutctures that one usually use while loading a model to be rendered with openGL primitives.

[CppOgl]

Actually, NeHe's tutorials are not always useful which is why I'm a bit stuck on loading external models. Otherwise, Nehe's site comes on the first page when searched in google.

[Heisenbug]

@CppOgl: When I was studying openGL nehe's tutorial have been very useful to me. But I think what you have problem with seems not related to opengl, but to file parsing.

[CppOgl]

Could be. I have seen many model loading tutorials but most of them are never helpful

[user786653]

@0verbose: It wasn't meant as a criticism of your post, the OP is extremely vague, so I was just pointing out that perhaps the OP was looking for something more like this. (Not tested, found by googling "asc opengl" where asc was just the first text 3d model format I could think of).

[Heisenbug]

@user786653 : don't worry. no problem. even the criticism are always well accepted. I think that everyone of us should be here to improve his knowledge.