Broken quads, weird rendering? I have a bit of a problem, at the moment I'm creating a few rocks for game purposes. Im starting of sculpting them and then baking them from multires, and applying that to the lowest "subdivision", just plain hi-res to low-res. 
Now the problem I have ran into is that when i use the lowest subdivision all my quads are "broken" and when rendered it looks all weird(I'm attaching a picture of it). And this is not a one time thing, this happens on every rock i create! 

Now my question is, how do I solve this? without having to manually change every vert, which i tried but it took like 1 hour, and when i was done i noticed that changing them made a bunch of other quads get broken instead. 

And is there a way to get around this completely? 
And i have also noticed that this only happens with Cycles and not with blenders internal render!
Select your mesh.
In the object mode in the left panel of your 3D view there is bunch of options such as trnaslate and rotate and...
In Shading section you can see smooth and flat button side-by-side.
Click on flat then you'll see your mesh as it is.  

If you want to use smoth shading option, your mesh should be hi-res (at least a little bit) or it will be like what you can see in your attached image.  

Take a look at this (the same object all the time):