I have this problem in my OpenGL project but i will show you the same thing over blender3d with video. So I believe that I will better explain the problem. it is just 30 seconds. Take a look. Youtube LINK
How can i fix these problem ?
As others have already pointed out, it's called Z fighting, and happens when two or multiple polygons are close to eachother (depth-wise) and the framework has trouble distinguishing which should be drawn over which. At its core, this is caused by floating point inaccuracies.
All that is nice to know, but how do you fix it?