Making noise for terrain of the game ( OpenGL + C++ )

Question

hi all, I want to make some noise for the terrain of the game. ( like minecraft )

I tried with rand() function but it doesn't look pretty well
this is what I have: https://ibb.co/eiv4M6
this is what I want: https://ibb.co/i1Ps8m
can someone help?

Answer 1

Instead of making each block’s elevation completely random, make a few points random, then the ones in between transition in elevation between them. The more points you make random, the more unordered it will be. Tweak the numbers until you get what you want.
Although congratulations for figuring out OpenGL, I’ve been trying for ages some success in understanding but none in remembering.

Answer 2

Jacob Pembleton,
This is my OpenGL learning source: https://learnopengl.com/
it completely explains everything. I think it's useful for you ( if you still want to )

Answer 3

@kurwius
sorry, but I don't understand this part:
extern float Gradient[IYMAX][IXMAX][2];
what I have to assign to it ?
and can you give me an example.