repeating hole pattern or texture on surfaces (climbing wall drill holes)

Question

Im trying to replicate the drilling holes which can be found on climbing walls. They are uniform in shape and should tile with the same distance and should not be cut on corners (getting half holes for example). I've tried different methods like using a texture and using different nodes (polka dot generation with all sort of different math nodes) to replicate this effect but none of them seem to do the thing I want to do or I get some weird black mesh results and it srews up (I am also pretty new to Blender and not very good at it).

This is an example of what I want to achieve.

My question is, what would be the best method and how would I achieve this? cutting physical holes in the mesh, or make a texture with some sort of bump/displacement mapping since the camera is a bit in the back and does not really show the actual holes from a distance.

Be advised that my mesh is not just one flat surface but consists of different surfaces with different angles. This is what I currently have;

preferably I'd use the node editor (im using cycles render engine) for maximum control but I haven't found any decent solutions which actually make it sort of look like the holes I want them to be. If anyone has some sort of solution or can point me in the right direction that would be much appreciated.

Answer 1

Final:

Overview and Node setup:

You can use node setup with dots. The requirement is to have proper UV map. As far as I can see in your picture you have triangulated mesh so it will be a little bit harder to UV Unwrap it. I have used Follow Active Quad method (check it in my answer) but I have created quad based mesh.

As for the node setup it's from someone else (can't remember where I've found it).

You can manipulate dots size, position and gaps between them by three Value nodes. Also near the end of this setup there are two Mix RGB nodes, one is for Bump node (black and white colors) and second one for wall and holes colors. You can also make second one as a mask for some advanced texturing. Note that I'm using Principled BSDF from Blender 2.79 RC2 but you can use any shader you want.

Answer 2

You could try particles. However this is destructive and you have only little control over the positions of the holes.