# making holes in objects

hello, noob here, so forgive me if it’s just too simple
(but I couldn’t find it in the knowledge base)

let’s say I want to make a cheese with holes in it. So I start with a simple model: a cube with sphereshaped holes in it.

I tried to do it with a simple mesh cube and bringing that in contact with a sphere that was transparant (‘invisible’). And yeah, it formed holes in the cube.
The problem is that I don’t like the way the holes are created, it simple destroys the face of the cube, but you don’t see anything behind it.

So how do I get this effect? Somehow I need a ‘solid cube’ that can react to incoming objects (the spheres)

I hope this makes sense

do you know booleans? you can substract the sphere from the cube. seelct both and press W >> subtract

Yeah, booleans would do the trick. Because I’m a bit lazy, I might just use a displacement map. In some 2D program (GIMP2 or Photoshop - probably gimp as it’s free), just make a circle with a spherical interpolation from black at the perimeter to white in the centre. Duplicate and resize the circles a few times and make the bits in between circles all black (it’s good to have the circles on layers so you can move them easily) then just wrap it round your model as a displacement.

This saves you having to make loads of spheres and boolean intersections. Also, if you do the displacement map right, you get perfectly spherical holes. It’s much easier to change the configuration of the holes too because you just change the 2D map by moving the circles around. I think you can also change displacement maps to geometry if you wanted.

wow, thanks… yeah booleans work great… (but there is no subtract option, I do it with the difference option)

thanks for the displacement map idea too… but I can’t use it for the project I am now working on (it’s like an inverted pile of spheres inside a cube)

Displacement maps are great when what you want is a visual effect and don’t need the actual geometry.

Depending on the situation, it’s also sometimes useful to start out by creating the desired geometry on a two-dimensional plane and then extruding it. For example that’s a great way to make wheels and such; much easier than starting out with a cylinder. It seems to me that in various situations that would also apply to things with holes in them, like cheese.

Hmmm, I think you are mixing up a normal map and a displacement map.

Disp maps do generate actual geometry and are really useful imho.

I don’t have substract also and difference dosen’t work. Which one should I select first? The mesh i want to cut out from the other or the mesh that stays after boolean with a hole in it?

When I tried booleans I couldn’t get it to work. I did the extrusion/sword tutorial where you make a handle, hilt and blade. Everything looked great until I decided I wanted the handle and hilt to be one mesh. So I did WKEY>>Union and I got a mess instead. The handle was still intact, but the hilt was destroyed.

You shoul have tried a CTRL-J that joins the meshes.