Making a Cutout to in Low Poly Model without affecting the surface flow I am making a model of Helicopter. Its comparatively low in polygons. I want to create a cutout in it. Deleting faces or doing boolean operation on major portion of model, my model becomes a mess and shape drastically changes. Can anyone suggest what is the correct way to do it.





Adding more geometry also causes the shape to change.
The "problem" is caused by the subsurface modifier.
it's the expected behavior.

You have a few options here:

— proximity loops: use ctrl + r to create supporting geometry around the edges of the hole

– edge crease: select the edges around the hole and press shift + e to change the crease weight (the edges become red)