Irrlicht Engine

i want to know the why?

isnt good use pictures?

or the better option is draw everything

for example if i want to do the floor with grass, so i take a pic of a pretty grass

what do you think about it?

thank you

they do use images, for example in oblivion.
In oblivion they are compacted into BSA files.

If you look around other game installations you will find the image files somewhere, but in most cases they are compressed along with the models.
If you find a massive single file its probably it.

its just like using .pk3s

Edit: unless you mean why do they make the textures in programs like photoshop, where the reason is partly because they tile better if you make them yourself, and because it can look wierd if you use photos

This sort of thing just depends on the game and who's making it. Some people will go out with a camera to get their textures, some people will make them in photoshop.

you will have to edit the picture you took IRL so it looks good when multiplied side by side on a terrain, but of course you may use them, and lots of game do ! (as long as their graphic orientation allows it -- realistic)

If you mean: 'why don't they use photographs as background/environment?'
That would certainly look good and realistic, until you move your character/camera, as photo's are 2D and for many games you want to move in 3D.