Welcome to Normals in Blender! In this
video we're going to learn about normals,
why they're important, and how to fix them if they've gone wrong.
Let's hop over into Blender!
So here we have the periscope, which we've reduced to 12 vertices,
and we're going to do something a little silly, we're going to
push it through itself. So with the Edge Select
Tool in Edit Mode, I'm going to select this top edge
and push it through itself at the back here.
Now you can see it's gone a bit of a funny color,
If we more around now. It's not quite rendering how it was
before. Now when it comes to your
normals, they are incredibly important. If we were to export this now
to another 3D package, it would not render
correctly. So I want to show you now how to show
your normals, so you can understand A which way they're
pointing and B how to correct them.
So over in the Properties Pane, if we scroll down there are
two sections that we're going to focus on. One is called Shading
and one is under Mesh Display, Normals. So
first of all, let's do the Mesh Display! Now there are several
types of normals but, in this case, we want Face Normals. So we're going to click
the Face icon there and we're just going to increase the size a little,
and that shows us which way our
Face Normals are facing. Now, for rendering
purposes, light will come in and it will strike a surface,
but if the normal isn't there, if it's facing the other way
like these ones are here, you end up with something like this.
So go up to Shading
and turn on Backface Culling. Now Blender's quite
cleaver, it just demonstrates the 3D model for you.
However, in most other programs you'll get a model that
kind of looks like this, with this weird
sort of display going on. It's all see through but only at certain angles,
and that just won't do, it would look absolutely silly when
it comes to exporting it into another package.
I'm just going to turn on this other one here, called Ambient Occlusion. It just
makes it, you know, highlights it just that much more. What's going on
here as we twirl around, it just looks, well it looks a mess
and it is a mess! So how do we go about sorting this
out? Well there are a couple of ways, so in this case,
we can pick Face Select whilst we're in Edit Mode,
we can click the face we're referring to, go to Mesh,
Faces, and Flip the Normal around.
Now that will enable us to... Well now the
normals are facing outwards, and we can do the same for all of
these faces.
So guys, I have a challenge for you!
In your assets
you will find a file called Normal_
Mess.blend. I'd like you to open up that file
and set all of the normals to face outside.
Go pause the video now and give that
a go!
Welcome back! Let's show you how to fix the normal mess!
So if we go and open up Normal_Mess...
So here we have the normal mess, and it looks
like we've got some patches. It's almost like a Rubik's Cube
going on here, and these patches have the
normals faced the wrong way. So we can just check that by opening up the Properties
Pane, going to Shading, and turning on Backface Culling,
and whoa! We've got some holes in our mesh and it looks horrible! So as
you can see, this is how it would import into
another package, and that's not what we want. So let's hop into Edit
Mode and see if we can solve this! So let's select the object
first, hop into Edit Mode, and there we
go! We can see... Oh, naughty naughty! I left
all of these faces selected. I better go edit that for you guys,
so [Laughs] you don't have so much of an easy job,
and so we could go along and we could select the faces
going into Mesh and going Flip Normals, to put them
right. And of course, you can hold down Shift, as you go through these,
and go Faces, Flip Normals. Ah the other
thing you can do is, you can select everything. So we can go down to Select
and go Select All.
If it doesn't do it the first time, it will deselect if anything else is selected.
And then, we can go to Mesh,
and along here, if I put my glasses
back on... There we go!
So Normals, here we go, Recalculate Outside!
That's the one we wanted, and that will flip them all so they're facing
outwards, out of the model. And finally, we can just
check that with one other check, and
if we scroll down here, we can turn Face Normals on and just extend the size
and we can see they're all now facing outwards.
How did you guys get on? I hope it was good!
See you in the next lecture!