How to import an image using openGL [closed]

Question

I am new to openGL C++ and what I wanted to know is if there was a pre-existing function in the OpenGL library that would allow me to import a 3d or 2d model?

For example, if I make a 3d image using photoshop, or a 3d model using 3ds max could I use a library in openGL example (not real function): glUse3dimage(3dmodel); ?

Or would importing images be more difficult and I would have to make my own function? I am not really a good programmer so I wanted to see how difficult this would be.

Another question I had was if this was difficult would this be easier using openGL with another language? For example openTK with C#?

Answer 1

There are no specific file handling or file format APIs in openGL http://www.opengl.org/archives/resources/faq/technical/miscellaneous.htm

You could dump textures of vertex buffers direct to disc and reload them, but it's much better to use some common 3D model format, like .obj

I would also recommend you get MeshLab to allow you to view and test your models independantly

Answer 2

No, thats not within the scope of OpenGL itself.

To load 3d models, one good tool is the Open Asset Import library:

http://assimp.sourceforge.net/

For 2d models (assuming you mean images here), use whatever library available in your language/framwork for loading images, and then draw the pixels using opengl's functions.

Answer 3

OpenGL does not specify a standard for model or image data. Which means you can import data in whatever format you want. Which also means you have to write/obtain code to load the data in whatever format you want. I once implemented a parser for the 3D Object format. It was pretty straightforward, and many modelling applications at the time could export basic geometry into this format. If you want to load more sophisticated models (maybe with procedural textures specified, or animation data) you might want to look for an existing library that can do that, though it would also be a good learning experience. ;) There are many libraries for loading image data, I think I just found some from BMP loader code and used that.

I can't speak to using OpenGL with other languages, as I ever only wrote C and C++ and a tiny bit of Objective-C code for OpenGL. I know of JOGL which would let you use Java to write OpenGL applications, but I have never used it myself.