Step by Step BASIC Tutorial? (Blender/OpenGL)

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1

Ok, i am a complete nub to the modeling process, and especially. I am new to OpenGL but i have enough knowlage that i can atleast figure out my problems via Google Resources.

However, with Blender, i know so little i litterally cannot even google my ass outa this lol. Its not so much commands, what they do, ect. I need help step by step with the whole process.

So, say i want to make a simple eye, or building, or hell, some dice. Can someone point me in the direction to a tutorial that is for the most complete basics of blender, to get me from point a (a blank Blender screen) to point b (a running OpenGL program with what i have made in blender).

Now the OpenGL side i should be fine like i said… hopefully, too be honest i know so little of blender who knows :p.
I dont even know the general modeling process. I’v scanned tutorials on Blender, read quick start stuff, but im still lost when pertaining to OpenGl.

Thanks to any help!

  • Zeus
2

Try “Basic Training”, and other tut links in my sig.

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3

well, there is a bunch about the modeling technique, you really ought to be able to find what you need

[and you’ll need a lot of practice, the tutorials will only show you the tools, not how to best use them]

well anway, to export to opengl you’re best off writing your own exporter/importer

python is pretty straight forward, you could probably become proficcent in a couple days. Also, the blender api is well enough documented.

but anyway, here are a couple useful things in python:

import Blender
print dir(Blender.NMesh)

will print:

[‘Col’, ‘Face’, ‘FaceFlags’, ‘FaceModes’, ‘FaceTranspModes’, ‘GetRaw’, ‘GetRawFromObject’, ‘Modes’, ‘New’, ‘PutRaw’, ‘Vert’, ‘doc’, ‘name’]

or… pretty much the same thing you get in the docs:
http://www.blender.org/modules/documentation/236PythonDoc/NMesh-module.html

or, you can:

import Blender
print Blender.NMesh.Face.__doc__

to see the doc string [showed on the same link as above… the docs rule]

well anyway, in blender verticies store only locations [the uv coordinates they store aren’t the ones you want], you get the uv coordinates and vertex colors from the face objects [this allows them to change across edges]. You’ll probably want to build triangle strips or something, which will require finding discontinuities in these and trying to cross them a minimum of times.

or you could just use gl_triangles… but this comes with a performance hit.

4

well, there is a bunch about the modeling technique, you really ought to be able to find what you need

I just cannot find anything that goes from zero knowlage, and involves OpenGL lol.

But i’ll give Fligh’s links a readthrough and finish scanning the links on the sticky topics. But ya, like i said, my main problem is a complete lack of knowlage of the basic concept behind exporting from a modeling program. Most of the tutorials on these sites seem to assume knowlage of what said programs are lol.

I fully relize how complicated the program is but im a fast learner if i can find the right materal to get the ball rollin hehe, thanks :slight_smile:

5

You are attempting to do too much at once, learning opengl programming and modelling at the same time (the two aren’t really related). I would proceed in the following steps.

  1. Write a simple opengl program where you can spin a cube using the arrow keys on your keyboard. A cube is trivial to calcuate the coordinates for.

  2. Learn to add textures and shading to your 3d cube in opengl.

  3. Learn to use indexed vertex arrays in opengl.

The following site is probably the easiest to learn the above from:

http://nehe.gamedev.net/

  1. Now that you have the basics of opengl programming down. You can learn to model a more complex object.
    This is where the blender tutorials come in.

  2. Export your object in obj format. Import it into Anin8or (a free 3d prog google for it) which can export C-source code. There is some example code on the site but it is hard to locate if I remember correctly.

  3. You should be able to use the exported code in your opengl program.

Hope this helps,
GreyBeard

6

#5 makes sense to me, for the mostpart the blender to ogl answers i’v recieved still puzzle me lol.

but #1/2 no prob, done a long time ago (though i’v been teaching myself flash also, so im a bit rusty lol), #3 i never did.

So im roughly on #5 atm, i just had no idea what to do involving modeling/Blender.
Hopefully i can piece enough info over the next few days to make sense of some of it. Once i can complete a simple project like make a cube in blender and bring it to OGL, then i can start learning lol.

Thanks again :slight_smile:

7

or the mostpart the blender to ogl answers i’v recieved still puzzle me lol.

You seem to be speaking like opengl is a file format which it isn’t. Opengl is a programming api and a fairly low level one at that. For example if you want to use tga images as textures you have to write the code to do it. If you want to import a 3d model from ANY 3d application you have to write the code that places the data in arrays that opengl can use – there is no built in code in opengl to convert automatically from any model format.

If you are at stage 5 as you say you are you should KNOW what data opengl needs to draw your object and it isn’t difficult using python to extract the information from blender to whatever format you want. It is up to you to write the code to read your formatted data and place it in data structures opengl can use.

GreyBeard

8

Ya see thats one thing i didnt understand, i have a targa loader/texturizer (however not written by myself, just modified), i just didnt understand the concept of modeling.

Such as you said, blender will export a file format containing my model and i have to write a reader like i do for bmp/tga ect… formats.

I’ll play around with Blender and hopefully figure enough out to peice it together.

Thanks

edit
And by blender to ogl i didnt mean ogl is a file format, i ment the process of taking what i build in Blender to OpenGL. Just like taking any external thing (images, ect) to OGL.