Original subtitles

Outlines! We've discussed them a little bit at different moments throughout the course.

Here we wanted to bring a bunch of different ways to create outlines all together into one section

to make it easier to reference, so let's get into it. As I record this the official blender version

is 2.92 that we can download here. But if we come over to the download page and scroll down a little

bit further to where it says go experimental we'll see that we can get access to 2.93 alpha

for various different operating systems and from there we can launch into 2.93 which you

can see i've got open here and i've got a simple scene with a few basic primitive shapes and we're

going to need 2.93 because it's got a cool new very useful feature for us and probably the

easiest and fastest way to get started for some decent outlines and that's the grease

pencil outlines. So the way we get started here is just simply go 'Shift A' to add in a grease pencil

and we've got these three new options down here at the bottom don't worry we can actually change

this after the fact so for now i'll just click on 'object line art' and now we have a new grease

pencil object added into our collections here. I'm going to put that into its own collection actually,

i'm going to press 'M' and then move that to 'grease pencil stuff' and click on OK. So this works

off of a camera and we don't have a camera in the scene. So i'm going to have to go 'Shift A' and add

in that camera and as soon as we do that we can see we actually get something show up in the view.

Let's turn on our viewport overlays just so that we can see everything and what i'm going to do is

press 'ctrl alt and 0' to snap the camera to about this position and i'll come over to the settings

of this camera actually and just reset a little bit of the rotation on this and also a little

bit on its Y position there just to straighten it out a little bit. To track the camera straight back

a little bit we can just double tap G and move the mouse a little. And here now we can see our

grease pencil outlines. If we come over to the 'line art' we can see actually this is simply a modifier

and we can see our source object is the cylinder. We could instead of setting this to object set it

to the whole scene and now we can see that we're getting outlines on everything. Or we could be

a bit more specific and say potentially this shapes collection (which probably makes the most

sense in this case) this creates its own layer here called 'Lines' and also gives it a material called

'black' which is just a simple stroke material. Come over to the modifier again we can see that layer

and material plugged in here so we can change quite a lot of these settings after the fact. Now

as mentioned it works off this camera position so if we were to jump out and take a look from

this angle we can see the illusion breaks quite a lot especially on these more curved objects

but jumping back into the camera everything looks smooth in fact i can go Shift ` (the accent grave)

to enter into a kind of fly mode and use WASD to zoom around the view here and

we can see it is actually updating perfectly fine. I'm going to right click though to reset the view

back to where we had it and before moving on we can just take a little bit more look at what the

options are here, nothing too exhaustive just the main beats. So disabling all of this all of these

options we can see that essentially our lines the category of lines are all summed up in this bit.

The contour would be the outline, the silhouette i should say, the material borders are fairly

straightforward should we select this cube for example and press 3 to select this front

face, 'I' to inset it a little bit like this and then let's come over to the materials click on the plus

icon to create a new material, i'm going to start off by slotting in that second material but i'm

going to click the assign which currently doesn't make too much sense because it's actually just

the same material but as you can see now we do actually have at the border of those two materials

a nice little outline. Typically though that would be a different material so if i just click on the

6 there and change this to some other color that's typically how we would be using this.

If we did instead for example want to do that so 'I' again to inset there and rather than using the

same material as a different material slot so let's select our 'line art' instead of using our

material borders we could just use our edge marks instead. So we would select our cube come in here

and with those four edges selected we can go 'ctrl E' and then mark a freestyle edge. We can see they've

gone a slightly different color there and if we 'Tab' back into object mode we can clearly see our

extra outlines. Let's select our 'line art' again to get back to the options, the next option we've got

are intersections. Now these are pretty interesting because if i move this sphere to intersect with

the cube we can see the extra outlines that we're getting there but if we take this cube,

in fact i'm going to make a new one by tabbing into edit mode and then going 'shift A' and adding

in a cube but let's take this cube over here and intersect it and then tab back into object mode we

can see we are actually getting some intersection so that's even within the same object. Let's scale

that up a little bit larger and place it on the left side, tab into object mode we see that's still

working. Let's go over to our line art and turn on the next setting which will be our creases this is

essentially our internal lines so the two main ones kind of top and tail this, so the contour

and the crease and we can control our crease with the angle that we've got here so as soon

as we pass 90 degrees we're going to see all these pop in. In this area of the modifier

we have a little bit more option for example the style so we can increase the thickness

or decrease the opacity in this section, i think this can get a little bit confusing because we do

also have an opacity for the layer itself we also have the same again for the actual material but

to make things a little bit more interesting, (let's just move our sphere back over there a little bit,

zoom in a touch more) here in the modifier for our line art (let's just turn off the overlays again

over a moment) we could actually collapse this modifier here and then instead add a new modifier

for example the thickness modifier. Let's set it to uniform thickness and now we can control our

overall thickness from here but we can also add a custom curve and create some difference like this

so i believe the start of a stroke would be very thin and then at its thickest in the middle and

then at the end of the stroke would be thin again. This is probably a little bit easier to see if

we were to go 'ctrl tab' move into draw (mode) and then let's take our strength setting all the way up

and then let's just left click and drag in the view there and hopefully we can see there that

is exactly what's just happened so it's thinnest on both ends and thickest in the middle. So with

this modifier i'm going to turn off the visibility of that in the render and in our viewport here and

also take a look at the noise modifier and turn off the randomize here and this is going to allow

us to create some variation so lots of position variation or we could create different opacity

variation by increasing our strength or thickness variation again by turning up this influence

slider for how we want the noise to affect our various properties. The noise scale at zero is

quite large noise but we can crank that right up if we find that we need a little bit more points

for which to create our noise with we can actually add a subdivide modifier and left click and drag

that above the noise, and let's turn up the amount of subdivisions a little bit and now we can

see we're getting things pretty fuzzy indeed, so let's turn down the amount that that is happening,

and maybe the amount of thickness as well. By default we can see that our subdivisions are set

to 'Catmull Clark' which is why things are rounding out on the more angular surfaces over there but we

can just set that to simple. That gives it almost like a nice organic wobbly but human feel to it.

I had a go at putting together a very basic scene, something with a lot of simple shapes

nothing much beyond basic insets and extrusions and then use these very same ideas for the grease

pencil outlines here so making it a little thick in the middle there, giving it some extra points to

work with and then just throwing some noise at it, mostly on the thickness but a little on the

position there. i think it's come out pretty nicely, this is just the simple solid shading workbench

engine but I tinkered with some lights as well so that in the rendered view we get a little bit

of high contrast going with that extra lighting but either way i think it works pretty well,

and although it is a little bit sluggish in the viewport, certainly without the grease pencil being

baked, i think it's, uh, overall it's pretty workable. So outside of the modifiers we could just jump

back into our materials and change say the color of our outline, this way, we could actually change

the style from a solid to a texture. We don't really have any textures in the scene though

so i'm going to jump over to the texture paint workspace and in here just create a new texture,

I'm just going to call this 'square' and click on the color swatch and make the alpha all the way down

so that when we press OK we're going to get an image which is completely blank so far, and here

i can just draw in a little square, well it's not looking particularly square right now, i'm going

to press 'F' to scale up this brush just to cover more distance, and as i draw this very, very rough

square in, i'm leaving the edges of it completely free and with that done i'm going to click on the

image there and just pack it into this blend file, and then let's switch back to the layout, and then

over here now we can find our square texture, and as you can see, it's now like a dotted line. We can

adjust how much we want to blend in that original base color, and we've also got the UV's

that we can scale up or down to our satisfaction. Let's turn off the 'line art' by left clicking

dragging across the eye and the render-ability there, actually let's find our 'shall we see it in

the viewport' option and also disable it there that way, when we press 'alt H' it won't keep popping up

in our view. So in a similar way, something that we can do is just simply add in our own grease pencil

object set it to blank, create a layer for it, create a material for it, and then 'Ctrl tab' into

draw mode, and then as we draw in the view here we can get some grease pencil strokes going, however,

i'm going to undo that and set the origin to be the surface, and set the offset all the way down.

So here now we could actually start to draw on objects and create our own outlines to match.

That's going to be tricky for these kinds of things where we need to determine where the

border should actually be, the actual outline, the actual silhouette, the contour as the other

'line art' option was categorizing it as, but in certain circumstances, probably more angular options, this

could actually be quite a nice effect, depending again on the overall message or the general style

or mood that is trying to be created. Again keeping within the grease pencil realm we can go 'ctrl tab'

to switch into object mode. Let's select this object here and let's come up to the object menu

and come down to convert and we can convert this to a grease pencil object. Let's come over to our

options here and we can click on 'keep original' and here we can find another object in our view, so i'm

just going to bring it down here a little bit and here we'll notice that we have the cube stroke and

we have a couple of materials, 2 fill materials which means we can come over to the fill material

and color this and then we're getting that different hue that we had before.

The problem with this is that we're not really getting any intersection lines, in this example,

and also every single edge has been converted to a stroke so we would have to go through and manually

alter what we want to keep and what we don't. But generally speaking grease pencil has a lot of

potential for this kind of stuff, especially with the new options that we've got down here in our

grease pencil add menu. With the grease pencil side of things out of the way i've jumped into

blender 2.92 so for this recording we're back in official land and what i'm going to do is

just disable the grease pencil collection here, we don't need to see that now and for this next way

of generating outlines in blender it's going to be pretty much the most simplest, the most basic,

the least customizable, and it's probably just worth quickly highlighting here, and that's in

the solid shading view we can turn off the x-ray let's make this flat actually, give it a sort of

super basic toon shading, which we could set to a particular color, so for example let's set all

the objects to a slight blue and - as we can see down here - we have our outline. Now it's tricky to

see because our world background is quite dark so let's take our viewport here and just make this a

little bit lighter and then we should be able to start to see our outline. It'd be probably more obvious if

we just come down to our outline color swatch here and make this a much more obvious red for

example and that means that we can now take our background a little bit darker again to be able

to see it even so it's still quite slight and it's only just about creating the contour,

the silhouette for us and we can see there's no intersections happening here between these two

cubes of the same object but as soon as we start overlapping different objects we can see we are

getting various intersections. So depending on the project the solid shading view this most basic of

work bench renders might actually do in some cases. Aside from using the flat lighting we also have

mat cap options and to pair with this maybe we would probably use this little toon matcap which

might help or we could use our own matcaps. It's actually worth pointing out that if we had

a matcap which looked a little like this or like this one where just at the edge of the sphere was

dark then we're gonna get at least a little bit of a kind of outline that we can use depending on

the falloff that we've got of course. That helps us segue into another option which is a shading

option which is basically doing the same thing as that matcap but perhaps in a way we could

argue that it's even simpler than that which is simply using our fresnel. So if we use the input layer

weight node and ctrl shift click on this thanks to the node wrangler add-on it'll automatically hook

it up to an emission shader for us so we can see it clearly in the view and here i'm going to take

a math node and drop that in afterwards and in fact i'm going to take the facing instead of the

fresnel and let's take that down to zero so it's not actually doing anything and the reason

i'm using the facing is because it's just going to take the very very center the face that is exactly

in alignment with the camera it's gonna make that zero and at the very very edges it's gonna make

that 1. So it's basically pretty easy to get a clean result. Switching the math node to power

means when we change the exponent value we can control the falloff (the way that it goes from

black to white) giving it a much softer transition through those values or if we'd rather have a fast

sharp transition between our black and white we can do that with a math node set to 'greater than'

or 'less than' and keep our value between 0 and 1 and we should be able to control the thickness.

This is a lot more effective on more curvy shapes as you can see with our torus donut and the

sphere but it's not working so great on these flat planes that we can see within the cylinder and

these cubes. This might work in a pinch though if all we're looking to do is create a mask of some

kind and that allows us to create a color mix rgb node, slot this into the mix and then we can choose

which two colors that we want to mix between. Or of course we could add our own textures into here

instead for different sorts of effects. The next method is a pretty popular one which is generally

referred to as the inverted hull method i'm going to ctrl shift click this principled shader again

though to start us off. Now we're still in our material preview and i'm going to come over to

the materials and click on the little plus icon there to add in a new material. I'm going to switch

it to the emission shader and i'll take that down to be pretty close to black then i'm going to come

over to the modifiers and then add a solidifier modifier. With that done all we need to do is tell

it to use the second material that we just created our material.003 in this case but just to keep it

clean i'm going to call that 'mat hull outline' and then come back over to the modifiers and then

set this to number one so we don't even need the name of it here actually. Zero would refer to the

first material and one the second and so on and so forth. The thickness of our outline is going to be

controlled by the thickness slider here but at the moment we can see that it doesn't really look like

much is going on we're getting a slight increase in the size of the sphere but not much else.

So what we need to do is come over to our normals we need to flip them and now everything seems to

have turned black. The final thing we need to do is to just come over to our materials again,

come over to the settings that we have down here and just select 'backface culling' also while we're

at it we don't want this to cast any shadows. Now we can see the outline taking effect and we can

hold 'shift and left click' and just see whether we want this to be an outline growing away from

the sphere or kind of giving the effect that the sphere is shrinking inwards. The interesting thing

about this technique is that we can pair this with other modifiers so i can click 'add modifier' and

give this a displacement modifier, click on the 'new', create a new texture, press this button at the end

to jump over to the image settings and i'm going to set that to a clouds texture and then jump back

to the modifier. The strength is pretty strong at the moment so i'm going to turn that right down

and now we're getting some interesting noise and variation to the outline. One main issue that we

might be having at the moment is that not only are the outlines being displaced but the whole object

itself, so for that we just need to come over to our vertex groups and click on the little plus

and for this we'll call it 'outline' and then jump back to the modifier and then when we create our

solidify shell that we're using to invert we can just tell it to output into a particular vertex

group. So in here in the shell section we can just select our 'outline vertex' group and then within

the displacement modifier we can tell it to only use that 'outline vertex' group. with that done now

we can control the strength of our outline, we can control the mid level and for the size of

the noise we just click our little button here on the right and that jumps us over here and we can

adjust the size. This isn't a perfect method of course we can't do intersections, let's just copy

this over to another object so we can see what's happening here, so let's turn on our overlays.

I'm going to select our cubes and then shift select the one we've got working and go 'ctrl L'

and then make a link for the modifiers and then also 'Ctrl L' to link the materials and here now we

can see we're getting a little bit of an effect. It's working better on the sphere because we've

got way more geometry to work with so in this case we might be tempted to come over and give this a

subdivision surface modifier to put at the top of the stack, so i'm going to left click and drag

that all the way to the top there. We don't want it to have sphere envy and try and smooth itself

over, so we're just going to switch to simple and then give this a few extra subdivisions. Finally

if we're using the displacement idea we can see the red 'outline' screaming at us there so we need

to come over to our vertex groups and give it a vertex group called 'outline'. Those are the steps we

would need to do if we were to copy this technique around. We are getting some internal contouring,

some localized overlapping of silhouettes happening a little bit but it's not really an

ideal method for every case. Another basic option we've got which we can use within our modifiers is

the wireframe modifier that we've got down there and we'll uncheck 'replace original' and then we'll

increase the thickness. Again we can see here we've got the opportunity to create a material offset

so in the materials i'm going to click on the little plus and give that to the 'mat_hulloutline'

again and then let's jump back to the modifier and set this to one, so in this instance

what we're basically doing is just creating some geometry for each of the edges in our meshes.

For a lot of curved objects this isn't really going to be a very good method but it can work

for some more boxy shapes like this but even in this case it's going to struggle a little bit so

if we just clear the modifiers from that and then shift select our cylinder and go 'Ctrl L' and link

the modifiers. We can see that on this object we've got all those supporting edges which we might

not want and there isn't a clean way to exclude particular edges even with the vertex group option

since that's at the vertex level and not the edge level. The same kind of limitation would occur if

we go really old skool to create some outlines and that's to jump into our UV editing options

and then with this object i'm going to select everything and let's just do an automatic unwrap

let's go 'U' and 'smart uv project' basically and click OK then from there what we could do is go

'UV' and export our uv layout save this anywhere it makes sense, we've got a few settings here on the

side which we can toggle on and off with our N key for the sidebar or use this little cog icon and

we can even dictate the format. The simplest option would be to just use our png and i'm going

to take down the fill opacity so it's just the lines themselves, click export uv layout then i'm

going to jump over to the shading options and then 'Shift A' to add in a texture > image texture and then

click 'open' find that uv layout, open that image up and then let's just ctrl shift click on this

and it's not going to make much sense on a lot of these other objects but on this one we should get

an outline for every edge. Let's just click on the uv layout png that we can see there and actually

before we take a look at the texture i've ctrl shift clicked the principled shader as we won't see what's

on our texture yet because the geometry the wireframe modifier is creating is in its way so

we'll need to remove that, and with our uv layout image we can control shift click on this. Instead

of the color output i'm going to go and click on the alpha output and now we can see our outlines.

I'm going to just use a color ramp node, drop this in, click on the little down chevron and flip the

color ramp and then we can kind of squeeze this in and make it a little bit more prominent if we want

and then otherwise we could then jump over to the texture paint, click 'N' to open up our sidebar and

i'm going to switch this to be erasing the alpha as we can see there and then zoom in on here press

F to shrink the brush down and i'm just going to left click across this area and as you can see

here the line is being erased. Now it is showing us the complete alpha here so what we might want to

do is switch over to our material preview and then we can see a bit more of what's really going on

as well as painting in the 2d window we can paint in the 3d window to remove certain edges too. This

old skool technique i include here just because it might help out in some other obscure way for

a more interesting result you could take the uv export out of blender completely especially if you

use the svg format and convert that into dashed lines in krita for example then when using those

results back as a texture in blender then things might start to get a little bit more interesting.

So from here i'm going to jump back to the shading workspace ctrl shift click on the main shader that

we've got here, select this and just remove the modifiers, same on this one and jump to the next

probably best but also actually happens to be the slowest option and does require a little bit of

experimentation. So i'm going to jump over to the layout workspace give ourselves a little bit more

room here, if we jump into the camera we can see our lineup here. If we press F12 at the moment we get

this render result. To make things a little bit easier on us i'm gonna just add in a light and

a sunlight double tap R to just rotate it so that it's illuminating from almost a 45 degree

angle. F12 again which isn't bad. I'm just going to jump over to the light settings and just change

this to about 5. One more render with F12 and i think that's looking mostly clean enough for us.

Now to press F11 to take a look at that render we just made we can't have failed to notice that

clearly by default no freestyle lines are being shown here and if we want to see them we're going

to jump over to the render properties tab come over to freestyle down at the bottom here and

just enable it there. Then when we press F12 we'll see it render and it just takes a second and it'll

add our freestyle lines on top. So essentially it's going to take our regular shading that we've got

in the viewport, so we might want to have a toon shader on here or just simple flat shading or

whatever we want and the freestyle engine is going to create lines based on whatever inputs

we give it and the settings we have for them and it will generate those lines, so freestyle really

is all about them lines! Up at the top here we can see we've got a combined and depth and a

'view layer' so there's a few extra options that we could throw into this and for that i can jump

over to the compositing workspace select 'use nodes' and we can see our render layers here, Ctrl shift

click on this to auto generate a viewer node so we can see the results in the background here.

But we can see we're only getting image alpha and depth if we come over to our layers tab here (let's

just pull this out a little bit) and scroll down we'll see here's all our freestyle options. There

are two main modes that we've got here, we've got the parameter editor mode and the python scripting

mode so really if you're familiar with python we can go crazy with all these lines. But i'm just

going to stick to the parameter editor to show a few basic things here. There's essentially just a

few sections here we've got the overall freestyle settings at the top, we have our 'line set' and then

at the bottom we have the actual 'line style' for that 'set'. We can interpret this as being kind of a

generator and then a style for what has just been generated. To see this as a render pass we're going

to need to enable this checkbox here and now we can see that the freestyle has popped up. If we

ctrl shift click down our outputs here we're not really going to see anything until we re-render

again with F12. With that done we can now jump over to the view layer and we can see our various

potential outputs, so we've got combined depth and freestyle so here it gives us the chance to

be able to use this as a separate render pass and use any number of compositing tricks, so blurring

or using it as a mask for something else. The options are kind of endless really, to join

these together though i'm just going to simply use a color alpha over node, drop that in there,

take our freestyles output and then plug that into the second socket of this alpha over node then when

we ctrl shift click we can see a more expected result in the background there. We've also got this

factor slider so we can decrease the overall alpha that we have there. At this point we could

also colorize it but we also have a lot of those settings within the freestyle options themselves.

So with this first line set we can see we're taking the silhouette, the creases and we can also

see things like the contour and the edge marks so if we were to jump over to the layout, take this

cylinder right here, press 2 to select this edge 'Ctrl E' to mark a freestyle edge and then come

back over to our compositing and hit F12. Notice that we still don't get any edge there but once

we enable our edge marking and press F12 again we should see it pop up. As i say i'm not going to go

over absolutely every option but we will take a look at changing the style to just a few of these.

So to change the actual thickness of this we're going to need to jump over to the thickness tab,

let's just crank that really high to 10 and then render again and we see the obvious changes there,

here i'm going to come over to the layout actually and jump over to the layer properties in this view

as well just so that we can see it all opened up in this window, give that a little bit more space

and then also i'm going to take this object double tap R and just rotate that around so we can see a

little bit more of it and then we'll render again. I'll set that thickness back to 3 though, we've

got these modifiers that we can add for example we can add some noise and then if we scroll down we

can see the settings for that and then press F12 again and we get some cool effects. So as you can

tell this is pretty powerful stuff with all the options available to us but we do need to keep

hitting render to be able to see the results. Just before we move on i'm just going to select 'strokes'

and just come down here to the dashed line section and you can see we've got 'dashes' and 'gaps'. I'm just

going to use this first group, so let's set this to be about 15 pixels long and then a gap of 5 pixels.

Press F12 and we can see where all our lines were, they're now dashed. Something pretty impressive here

is that we can actually combine things together so for example we can add an additional 'line set'

and set this to 'hidden' instead. For example come over to the 'color' set this to be something else,

something like this and then come back over to the strokes set this to be a dashed line, so 15 and 5

for example and then come back over to the first 'line set', disable the dashed line on that one, maybe

make this a little bit thicker at 5 and then come back over to 'line set' 2, so we have this one

which are all the lines we can see and then the second 'line set' will be only the lines that are

hidden. So we go F12, now we start to get this kind of effect. Other options include other versions of

blender, so for example at this link right here at graphicall we'll notice that there's this 'line

art' build for windows 64 at least, i haven't personally tried this build but seeing how

this is a chapter on 'line art' i think we should probably include it. Even the main developer for

the grease pencil stuff is making a comment here so it's great to see this kind of interactivity.

Speaking of other builds of blender this section wouldn't be complete without discussing the

ongoing BEER development and the Malt render engine, we have a chapter showing how to set

that up and get started and a key feature of this engine is its ability to create real-time outlines.

That is looking super promising and it's recommended to stay tuned to the NPR show and the

website in general actually for more options and updates on the non-photo realistic rendering scene.