Why does this happen? "Cracks" in my object


I couldnt come up with a better title…

I’m working on a bus in Blender, and I’m currently trying to do the front lights in my object. The light itself will be placed inside the body but when I’m trying to make a hole in the body, “cracks” appears around the area.

Is there any better way of doing this? I placed a cylinder around the area where the hole will be and used the knife tool to cut out the round circle as you can see above. Then I extruded the area inwards.



It’s a result of poor topology. Please, always attatch a .blend file with a specific, problem-oriented question like this. It’d be much easier to see whats wrong with your mesh