Depending on factors like how detailed it needs to be and how close the camera is to the surface it could be achieved in a few different ways. The quickest way to model them would be to use modelling boolean on the surface, all you would need to do is make the triangle shape and then go to boolean > difference(think thats the right mode, haven't got Maya open at mo).

You could also do this using a displacement map, either using a 2d package like photoshop to draw the triangle shape or a 3d one like zbrush or mudbox to sculpt the whole on the displacement map.

If it just had to be the illusion of holes then a bump map may well be easiest option.

Chris