Code. Play. Teach. Learn. Research. Demo.
Starter Tutorial (P5)
on Ancient Brain using the
- The P5 library is probably most suitable for beginners.
More experienced programmers may prefer to start with the
Three.js Starter Tutorial.
- In any case, this tutorial
- All links from this page open in a new tab/window, to keep this tutorial on screen.
Getting set up
Get an account
- To create Worlds, you need an account.
- Use "Register" in the menu at the top of the page.
- Register, and get your password via email.
Clone "One Cube World"
- Go to the page for
"One Cube World" (P5 version).
This is a simple Starter World.
less than 30 lines
of program code.
It displays a single cube on screen.
You cannot move the camera so the cube rotates to show you it is 3D.
- Click "Clone" to make your own copy.
- Go to the World page for your clone.
- Check your clone runs.
On the World page for your clone, click "Edit" to launch the editor.
- Edit the title.
- Edit the description.
- Go back to the World page and reload. You will see the new title and description.
First look at the code
- The program is a set of instructions for the computer to "execute".
- Instructions end with ";". This is important.
- Whitespace does not matter. You can add or remove whitespace according to taste.
- Comments begin with "//" (and continue to end of line). These are notes to the human reader and are ignored by the computer.
There is a lot to learn about
but you do not need to learn it all before trying some programming.
Change some code
You can change code, press "Save" and then "Run" the new code.
Nothing bad can happen.
You cannot damage your machine or our server.
Change the following:
- Change the cube size.
- Change how much the rotation angle changes each step.
Changing this can make a dramatic difference.
- Change the background color.
Here is a list of color names.
- Change the cube color.
- You can change the box to not be a cube by giving it numbers for all 3 dimensions:
box ( width, height, depth );
box ( 200, 50, 1000 );
Every time you make a change, press Save, and Run again.
P5 programs use the following structure
to define what code runs once at startup,
and what code runs every time step:
// Can define global variables and constants up here, outside both functions
// Instructions to be executed once, at start of run
// Instructions to be executed every time step
Note the chain brackets. These define the start and end of blocks of code.
We will now add some new code at certain locations within the structure.
Paint the cube
The cube is "painted" with a solid color.
It would be nice to paint it with a JPEG or PNG image.
Insert the following code at the locations indicated:
// Put the following right at the top of the program:
img = loadImage ( "/uploads/starter/earth.1.jpg" );
// Put the following inside the "draw" function
// Remove the line that makes the cube a solid color, and insert this line instead:
You will now get something like the following:
Upload your own image
- Web search for some image you want to use.
Right-click and "Copy image".
- Go to menu "User" - "My uploads".
Paste (Ctrl-V) and the image is uploaded.
- You can also select an image from your computer
by browsing files.
You need the exact file name of the image.
to point to your userid and your file:
- The cube will now be painted with your image.
Make another box
Change the line
to the following:
translate(250, 250, 250);
This makes a second box some distance away. Both will rotate.
Make lots of boxes
To see the power of programming, we will make lots of boxes,
using what is called a
Insert the following code at the positions shown:
// Insert this code at the top:
const noboxes = 30; // how many boxes to have
var a = new Array(noboxes); // array of the box positions
for ( var i=0; i < noboxes; i++ ) // set up the array
a[i] = [ AB.randomIntAtoB(-500,500), AB.randomIntAtoB(-500,500), AB.randomIntAtoB(-500,500) ];
// each entry of the array is a random (x,y,z) position
// (an array of three random numbers)
// Insert this code inside "draw", replacing the previous "box" and "translate" instructions:
for ( var i=0; i < noboxes; i++ )
translate ( a[i], a[i], a[i] ); // get box position i
This makes a large number of boxes in randomly different places, like the following image.
Increase the number of boxes until your browser cannot cope.
Don't worry, you cannot cause any damage!
Now we add some background music.
Insert the following code right at the top:
const MUSICFILE = '/uploads/starter/SuspenseStrings.mp3';
var music = new Audio ( MUSICFILE );
music.loop = true; // loop music forever
AB.standardAudioButtons ( music ); // create standard play and pause buttons
On some browsers (Chrome, mobile) audio will not play automatically, but only in response to user interaction.
So the code gives the user play and pause buttons.
See notes on audio autoplay on web browsers
and in particular on Chrome.
Use your own music
- Get some music you like.
- One site with free music is
There are many others.
- When you find music you like, download the music file to your computer.
- Then upload the music file to Ancient Brain.
- Edit the code to play your music file.
Errors while writing programs are normal.
The important thing is to understand where the error is.
- The editor warns you about errors using an X icon
on the left-hand side.
Hover on it for info.
- When you save the file, you will be warned again in the pop-up.
Some errors cannot be detected in the editor
and you will only find out when you run the program.
- Errors found when the program is run are displayed in the
To see the console, press Ctrl-Shift-J on Chrome and Firefox,
or F12 on Edge and IE.
See the "Docs" menu for all the documentation you need when coding.
You can also select code and press "Intelligent code help"
to get help on a specific function / object / word.
AB, ABRun and API
Ancient Brain defines a number of support objects and support functions.
You may have noticed AB.randomIntAtoB and AB.standardAudioButtons above.
AB is an Ancient Brain system object.
ABRun is another Ancient Brain object to define a particular run.
You may also have noticed ABWorld.fullwidth and ABWorld.fullheight in the original code.
ABWorld is defined by the particular
API we are using.
See the docs for
Clone and edit other P5 Worlds
and change them.
Many of them have a section of code called a
at the top.
This contains the easiest parts of code to change.
When you get more advanced, you will make your own entire Worlds.
The Worlds you create are only limited by your imagination.
Show it off
- The system will generate an image to represent your World.
To change it,
see "New image" on the World page.
The site works on mobile.
Show off your World to people on your mobile.
For some Worlds, touch will automatically drag and zoom the World's camera.
People can find your World using the search box.
So give it a good name.
You can embed your World on another website.
See "Embed code" on the World page.
- Comment on other people's Worlds.
The top menu turns red when you have a new comment.