Guild of Writers

Hollow Cube Study 1
With sweat dripping off the end of me nose, i would like to ask if anyone can give me a straight forward series of steps for cutting doorways?

I am simply planting a small cube (really, a hexahedron) across the future threshold in a solid wall, and trying to use it to open a hole.

Sometimes it works; sometimes i struggle with it and find out that i have to erase 12 previous attempts to find that the hole Was cut (at some point, but it did not show); sometimes other stuff happens. And when it works, i am too confused to remember/reproduce the correct path.

I am using Boolian Operations > Intersect and Difference. The problem is that i don't know the sequences to arrive easily at the hole in the wall: Do you 'a' away all the highlighted events after Bool Ops? Then what? Do you just move the highlighted events after one of the Boolian operations (which one?)? And if you do move the portion of the complex with the hole, and it is actually there, why do you have to move it – it has to be moved back?

And so forth and so on. Can any one tell me if i am barking up the wrong tree altogether; or if not, what is the precise (emphasize, 'precise') path to cutting the hole in the wall (once the cube is hollowed out)?

Hollow Cube Study 2



I have lots of color questions, but for now, can someone help me with this:

In the above pic i highlighted just one of the gray boxes. I applied the rust color to it that you see – but all of the boxes got sprayed. I guess they were down wind?

How do you paint only one highlighted object in a group? I would have thought just highlighting a thing would be enough screening, or masking.

Actually it looks like you have quite a good grip on this all.

While I use Booleans extensively with solid geometry, in my preferred modelling package, I don't really in Blender, preferring to add faces manually onto vertices on support lines, but I'll give this a shot...

I'll take it from the start, even though you are already familiar with it.

First of all, make one window an "outliner" window. This is a hierarchical list of all your objects, so when you add a cube, it will get an entry in this list -- the first cube will simply be called "cube" -- this is its default name, subsequent ones will get a trailing number: "cube.001", "cube.002" and so on.

I like the outliner - it really helps overlooking one's scene and should help you see what is going on here.

Now, starting with a new scene (menu: File/New):

- Add one cube.

Now, if you look in the outliner, there should be a "cube" entry,
with a little triangle with dots at the corners next to it. This
symbol signifies that the object contains a 3D gemoetry mesh.
This symbol can be clicked, to select this mesh and go straight
into edit mode.
Clicking the tiny arrow to the left of the object name,
will expand one level of the object's hierachy tree.
Never mind all this, right now, though. :P

When you add a mesh in object mode, Blender will automatically
jump into edit mode - we do not wish this, so...

- Return to Object mode.

- Add the second cube and again, return to object mode.

Now there should be a "cube.001" in the outliner.


I intend to use only "difference" (or "AND NOT") now.

So, after you have scaled and positioned the cubes, so that they
intersect, here comes the multi-select bit:


- First select the cube that will act as a tool, acting on the other.

Then, holding down shift...

- Select the cube that will be acted upon.

I.e. to use a real would analogy, you -first- pick up your drill,
with a suitable bit fitted and -second-, grabs hold of the plank you
want to make a hole in.

You may have noticed that when you got that second cube selected,
the outline around the first changed colour. This is because there
is only one main, or primary selection at any time - the others
just trail along, for the ride. -Should you (still holding down
shift) click the first cube again, IT will become the primary
selection, indicated by the white outline, as opposed to the
light blue one and then the effect will be reversed - that is,
it will become the plank, to the drill bit of the second cube.
The last selection is always the main selection and the medium
that the secondary selections drill, route, scoop, etc into.

- Do a boolean "difference"

--> Now have another look in the outliner. There is now a cube.002.
--> This is because we are not in actuality changing the original cubes;
--> instead a new object is created, in the shape of what we would have
--> if cube really did take a bite out of cube.001.

At this point your previous selection stands; you can now, as you
suggested, delete these two "source material" cubes, if you have no
further use for them -- they are already selected, so just hit "X"
to get rid of them.

You could, of course have kept one (or both) of them, to use for
chiselling away further bits of your new cube.002, in exactly the same
way you just did, which would result in yet another new "cube(.nnn)" object.

For the other two boolean operations (AND and OR), the selection order is less important, since the objects are "equals" there, rather than having a guilliotine/amputee relationship.


As for the colour; many objects can share one material. If you have a
"sapient pearwood" material assigned to fifteen cubes and change its colour
to ultramarine, you will wind up with fifteen ultramarine-coloured pearwood cubes wondering what the hell is going on.

Now, if your original cube here had a material assigned to it, that
same material will be on all the cubes derived from it.

If you bring up the material buttons, with one of your red cubes selected
and look at the box displaying the material's name, you may find there is a
number next to it. This tells you how many of your total number of cubes
are made from that material. At this point you can make a personal copy of
that material, for the selected cube, by clicking the number and confirming
the action with a second click. The new copy of the material will get the
same name as the original, with a trailing number, just as with the cubes
earlier. This material can, of course, then be added to further objects,
should you so wish.


Hope I didn't just make things worse now.... :7

Great, Jojon!
I've just started reading your post; and the "outliner" window makes so much sense, i had to stop and tell you. The idea of an "hierarchical list of all your objects", fills my planner's heart with warmth, apple pie, and everything -- or whatever the great computer (on Hitch Hiker's Guide) was supposed to provide.

Thanks

PS: While i've got you here, Jonon, could you please tell me about those tiny little pipes running throught the open cubes you did for my Gestoypahts plan. They look like the pipes to cooling fins. But i doubt it's A/C for the masses of TwoCities, right?

Jojon

The two cubes (one Actor Cube.001; one Acted-upon Cube) are built one inside the other, so going back into Object Mode hides the smaller, or interior cube.

When i place the pointer inside the visible cube for Selection purposes, it seems to automatically select the Acted-upon cube first, then the other.

And this is not the sequence you specified. How do i subvert that automatic selection?

EDIT: Jojon, I think the answer to my problem is that the cube numbers change; so it seems (i am thinking) that the new cube has become Cube, and the old Cube is now Cube.001?? For i think the Difference Boolean does dig out the gourd here, so to speak, just as it should.

Umpf, that was quite a task, however, I learned soooo much! I noticed later I forgot to smooth the bottom of the flutes, so some of it looks a bit rough... but overall I am sort of happy. I certainly had to make use of every single skill I learned so far!

Show Spoiler

The Pillar

Pillar.jpg (90.41 KiB) Viewed 3256 times

Fantastic, Sophia!

Umpf, that was quite a task, however, I learned soooo much! I noticed later I forgot to smooth the bottom of the flutes, so some of it looks a bit rough... but overall I am sort of happy. I certainly had to make use of every single skill I learned so far!

/gawk
Ooooh! Ahhh! I am amazed at how good that pillar looks, Sophia!

And what building is that, pappou? Part of Gestoypahts? (And thanks a million for helping, Jojon; I'm running on two hours of sleep now and I don't even have time to read this whole thread. )

LOL, I spent all day with it, and finally found an easier way of doing it... the one you see would actually lag the game to 2003 standards

I am beginning to think though it might be easier and faster to chisel the pillar out of real stone!

SO what's going to happen? Are each lessons going to be put in a different thread, a sub forum for this classroom, or anything? OR is it going to just be left this way?