Irrlicht Engine

Hello,
I'm using Irrlicht in my project and I have a problem with rendering scene on different graphic cards.
EDT_DIRECT3D9 mode works fine anywhere.
EDT_OPENGL mode works fine, but on the integrated graphic cards and some notebooks picture looks bad.
What I need to do for correct work in OpenGL mode?

Here is two screenshots from the same computer with integrated graphic card
Direct3D looks fine

OpenGL looks bad

seems your OpenGL drivers or card are REALLY OLD

i.e. the fuzzyness of the ground suggests that Trilinear Filtering is not available

if the grass pops in front of the brick (the outlines change) then the issue with the rendering is the standard "bit-depth precision" issue, where your near distance is too small or not enough bits in your ZBuffer (i.e. 16bit instead of 24bit)

If using windows... REMEMBER THE OPENGL THAT SHIPS WITH IT IS DESIGNED TO BE poop AND DISCOURAGE/UNDERMINE OPENGL!
Hence you need to download proper up to date drivers from your GPU manufacturer

thanx for help, the problem was in z-buffer bits.