How can I create a chaotic structure from a triangled mesh I have a cube, which I subdivided into smaller parts, which I then changed into triangles. I would like to reproduce something like this : https://www.pinterest.fr/pin/392657661240154630/

Now my cube is subdivided, though its faces are flat. How can I do to create those "bumbs" and "cavities" ?
If i understood the question

Press Shift+A Add cube.

In edit mode press W subdivide 

Press F6 and play with the settings with Fractal and Along Normal



To make the faces from Quad to triangulate In Edit mode Press Ctrl+T or In edit mode -> Mesh -> Faces -> Triangulate faces.