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Creating a tiled world with OpenGL

Answer 1

+2 A:

Jon Watte 2010-02-06 00:17:39

Wait, so, what do you mean by tile position and camera position?

Tamir 2010-02-06 00:59:16

Good answer, but if you want to be direct, take a look here:http://irrlicht.sourceforge.net/docu/example006.html

eMgz 2010-05-19 21:31:40

You obviously didn't get me.I know the tiles are 2D, but it involves the usage of models.If you take a better look in the video, you'll figure that the houses are models.

Tamir 2010-05-25 09:57:30

My answer is specifically intended for 3D models on a 2D plane (although you could use it for quads, too, I suppose).And, by "camera" and "tile" position, I mean just that -- the camera's position in (imagined) world space, and the tile's (model's) position in (imagined) world space.

Jon Watte 2010-06-05 00:16:14

Answer 2

+1 A:

The projection used by that video game looks Oblique to me. There are many different projections, not just perspective and orthographic. See here for a list of the most common ones: http://en.wikipedia.org/wiki/File:Graphical_projection_comparison.png

You definitely want perspective, with a fixed rotation around the X-axis only. Around 45-60 degrees or thereof. If you don't care about setting up the projection code yourself, the gluPerspective function from the GLU library is handy. Assuming OpenGL 2.1:

glMatrixMode(GL_PROJECTION); //clip matrix
glLoadIdentity();
gluPerspective(90.0, width/height, 1.0, 20.0);
glMatrixMode(GL_MODELVIEW); //world/object matrix
glLoadIdentity();
glRotatef(45.0f, 1.0f, 0.0f, 0.0f);
/* render   */

The last two parameters to gluPerspective is the distance to the near and far clipping planes. Their values depend on the scale you use for the environment.

Mads Elvheim 2010-05-23 15:35:10

Alright, thank you.So basically, this is the setup for the camera, and how do I scroll, and draw 2D tiles for example?I would be happy to get some information about the scale of the locations, like one unit as in twenty pixels, or what?

Tamir 2010-05-24 11:35:41

With a perspective projection, units don't map to pixels. And definitely not in a linear manner. And you're asking too many questions for me to answer here in the comment field.

Mads Elvheim 2010-05-24 11:50:53

I know unit don't map to pixels, I'm asking about the scale.What should be the interval of positioning between after each tile for example?

Tamir 2010-05-25 09:59:12

That would depend on the size of the tile. With a perspective projection, x and y is scaled by z. That is, z is plugged into w, and then x, y and z is divided by w.

Mads Elvheim 2010-05-25 12:28:39

Okay, so my solution was using a simple unit of 1 as the size of a tile in both factors (x, y).But now I get a little space between each tile, maybe it's because of a defect when loading the texture, here is my code: http://kono.pastebin.com/6sxqasph sorry for the shitty code.Thank you for your relevant answer.

Tamir 2010-05-25 17:45:40

Tamir: Everything you're asking now is like 4-5 new questions. I'll gladly help you more on a more direct manner. If you have IRC, please come to ##OpenGL on FreeNode. I don't promise I have an answer for everything though.

Mads Elvheim 2010-05-25 18:42:57

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Creating a tiled world with OpenGL

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