Using VBO

[Skatty]

Hello

Can somebody help me figure out VBO idea. How it work? I wanna do something like minecraft clone. So i have to define 1 VBO for each block(built from triangles and using texture) or just 1 VBO for them all and only change somehow texture?

[quew8]

Minecraft divides the world into chunks, each occupying an 128 * 128 * worldDepth volume. This makes it easier to do the dynamic world loading (loading the area you walk into, unloading the area you walk out of) and is a good size to make a vbo. Use one vbo per chunk. As for the texture, you have two options that are really sort of the same.

1) Use a texture sheet. This is one 2D texture divided up into areas with each area containing one image. Use texture coords to get the right image.

2) Use a texture array (OpenGL 3.0+ only). Which is "like" an array of textures. I have never used them but I believe the idea is that you use the 3rd texture coord to specify which texture in the array to use. Generally the above is easier and requires smaller VBOs (only 2 tex coords). Only use this method if you are using very high resolution images and it would exceed the max texture size to put several of them together. 

[quew8]

Also this wiki book http://en.wikibooks.org/wiki/OpenGL_Programming contains a section talking you through creating "GlesCraft" which is a Minecraft clone. It is a tutorial aimed at beginners so you might want to check it out.

Again, I haven't read it so I don't even know if it uses VBOs or not but other items there that I have read seem very good.