Making ventilation holes in a hockey mask style model I have searched tutorial videos and google for the answer to this but maybe I haven't been searching for the right thing, I basically want to make a grid of evenly spaced circles that can be wrapped over the surface of my model so that I can cut evenly spaced holes out of the mouth area for ventilation like a hockey mask. I want the circles when cut out to be perpendicular to the curved surface they will be set on, rather than all the holes cutting in the exact same direction. Is there a better way than making a grid of circles and manually warping them to a close enough curvature? I have found the circles to end up warping too much out of shape when doing this for my liking so wondered if there is a way to do this whilst keeping the perfect circular shape completely or almost intact. I have added a screenshot from a tutorial for modo with the orientation I want to achieve with my own ventilation holes.
If your mesh is clean and subdivided enough you can make as many holes as you need with the following method. If it has not enough edge loops you can add some with W > Subdivide Smooth or add and apply a Subdivision Surface modifier.


Select four faces, press i to inset, and scale down the inset.
Press W > LoopTools > Circle
Delete the inner faces of your circle
Now you have a hole
Add a Solidify modifier to give thickness to your shape
Add an edge loop around your circle if you want a sharper edge


If you want a low-poly mesh you can create a low-poly version of your mask, bake your high-poly version, and, in the low-poly material, recreate fake holes with Normal or Bump maps.