WEBVTT

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Hey there, welcome to Scripting for Artists.

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This is a video tutorial series on Scripting Blender.

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It is aimed at people

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who don't necessarily want to be a programmer,

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but for whom Scripting may be beneficial.

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And it can be useful for a lot of things,

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as we'll see soon.

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Before we start, let me introduce myself.

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My name is Sybren Stuvel.

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I'm a core Blender developer and

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I worked at the Blender Institute.

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I've experience working next to artists.

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I've worked on the Blender Cloud itself,

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and I've worked as a tractor in Flamenco.

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I also have a PhD in computer animation,

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during which I worked on the Blender game engine.

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After that I started working here

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at the Blender Institute.

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This series is about Scripting Blender.

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Basically

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letting Blender pushing its own buttons.

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If you have ever done any dump monkey work that

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takes a lot of clicks and a lot of repetition,

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this may be the series for you.

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Examples for Scripting would be useful.

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Our mass naming of bones or objects,

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or rendering 10,000 OBJ files in some directory.

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One thing to keep in mind is that

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computers are stupid. They will just do

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what they're told, line by line, word by word,

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and not really think about what you mean.

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So

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it's good to keep in mind that

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you have to be a literal.

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So that's it for the introduction of this series.

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Let's go and do something practical

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in Blender itself.

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Blender can be programmed in Python.

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That's quite a nice language

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that can be read and understood quite easily.

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Furthermore, it allows you

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to interactively toy around with it.

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So let's dive into Blenders Python console,

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"after I change my shirt", that is.

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So here is the default startup file.

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We can replace the timeline with the Python console,

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because we don't need the timeline right now.

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Let's do some computations,

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3 x 4 = 12, 2 + 3 x 4 = 14,

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because multiplication and division

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go before addition and subtraction.

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So if you want to do the addition first,

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you have to use parentheses,

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(2 + 3) x 4 = 20.

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Let's go and see if we can do something

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to that default Cube.

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If we press N in the Viewport for numeric data,

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you can see locations X Y Z.

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Let's move it somewhere else.

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So if you hover your mouse over the locations,

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you can see it in Python information,

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bpy.data.objects.cube.location.0,

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which basically means from

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Blender's Python Interface, get the data, in there are objects,

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from those objects, I want to have cube,

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cube has a location,

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and location has a few components.

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X is component 0, Y is component 1

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and Z is component 2.

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We can just copy this into our Blender Python console,

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bpy.data.objects.cube.location.0

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and this gives us the X location,

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and location 1

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gives us the Y location, and

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of course 2 will give us Z.

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Alternatively you can use letters.

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So there is actually a ".X", do exactly the same thing.

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I like those little bit better.

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It makes your script a bit easier to read

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if you just name them X Y and Z.

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This isn't limited to reading,

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we can also write to it.

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So we can set ".Z" to 0,

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and then is (0)

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or 1

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or Alt + 0

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which means increment.

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Increment by 0.1,

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and we can keep using this.

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I'm pressing the up arrow key in the console

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that gives me the previous command,

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and then press "enter", so you don't have

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to type everything by hand again.

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We can also assign to the location directly

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instead of to each component individually.

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By removing the last component and then

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assigning it three numbers in parentheses.

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For example like this,

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and then we set X Y Z at the same time.

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This also worked for Scale.

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And it also works for the Rotation.

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Except that on the Python side of things,

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Rotations always work with Radiance,

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and not with Degrees that you might see in the UI.

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So this might get

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a little bit getting used to.

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One more thing that may make things

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a little bit easier to type is that

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the Python console supports auto-completion.

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So you can do "bpy.date" and then

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press Ctrl Space ".object.cube",

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you have to type yourself,

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bu then "rotation" and then "euler".

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So this is done with Ctrl Space,

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can be really useful.

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Can also help you figuring out what is there to type

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in the first place.

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So there's a whole list of things here.

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This you can find in the documentation by the way.

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If you go to Help, and then Python API reference,

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then you get all these information.

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But we'll cover that in a moment.

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Let's look at some other things.

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We can find about Python in Blender User Interface.

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We have seen these properties of existing objects.

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Let's see if we can delete

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and maybe create some new objects.

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This is done with operators,

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operators are Blender's way of binding certain functionality

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to menu items or buttons in the interface.

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So what we can do is just hover over Button,

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and then you see the operator command.

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You don't even have to remember it.

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You can just press Ctrl C to copy,

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and then press Ctrl V to paste it into the console,

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and it will just work.

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So  now we've deleted an object,

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let's look at creating one.

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You press Shft A, then over an operator

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hover your mouse and you see

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"bpy.ops.mesh.primitive UV sphere add".

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So again, press Ctrl C and then in the console,

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press Ctrl V and "enter"

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and there, you have your sphere.

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It's a bit boring one, is the default one.

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Let's see if we can do something about that.

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Don't be afraid,

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if you don't understand all these options yet,

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I will give you some information later

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where you can find out exactly what they do.

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So let's create it

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with size equals 0.10

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at location 1 2 3.

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And there you have a really tiny sphere.

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Let's create a bit bigger one at a different location.

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It's that simple really.

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We've already found quite a bit of information

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in Blenders User Interface,

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but there is also Blenders API documentation,

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which you can find right

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here in Blender, Python API reference.

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It opens the browser for you with information,

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and you can

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use that copy paste trick again.

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So Let's see,

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Shft A, Mesh, UV Sphere, Ctrl C,

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then I go to the browser and hit Paste in the quick Search,

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click on the first link,

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and there you have the explanation of what is what.

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Another good source of information

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is the Python standard library.

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So what have we seen so far?

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We know that computer is stupid

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and just do the commands one by one which we gave them.

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We've seen how to use the Python console,

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and how to create objects, remove objects,

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and modify existing ones.

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We've seen what we can do with

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copying information from Blenders User Interface.

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And it points you to a few sources of information

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where you can find more stuff.

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So in the next video, we will look at

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Names and Objects because typing

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bpy.data.objects.cube.something.something.something

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becomes really boring after a while.

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See you in the next video.