Rendering Glitchiness

I though that the rendering would render properly...
but what actually happened was it glitched out
I also wasn't at the farlands. I think its a graphical glitch because i can still walk on the real terrain and take damage, but i see this glitched out random
terrain

I was going to do a survival lets play but then it happened. I don't know how to reproduce the glitch (I didn't record it though)