Creators – Week 8

This week we finished off our feeding animals game and played another challenge round. This concludes our second project and we’ll be starting on a brand new project after Christmas.

Collisions in Unity

There are two types of collider objects in Unity:

  1. A collider that acts like a solid barrier (standard collider)
  2. A collider that allows things to pass through it, but detects the collision (a trigger collider)

There is an “Is Trigger” check box on all collider components that allows us to change the type.

Standard colliders are used for physical interactions – like walls you can’t pass. Trigger colliders are used detect things being in the same space, but not physically interacting.

To detect collisions between two objects in Unity:

  1. Both of them have to have collider components attached
  2. At least one of them needs a RigidBody component attached

When Unity detects collisions, it sends messages to all components on the impacted GameObjects. We can choose to receive these messages by having the right functions in one (or more) of our components:

  1. For physical collisions we implement OnCollsionEnter()
  2. For trigger collisions we implement OnTriggerEnter()

These are similar but differ in information they receive.

Adding Collision to Our Prefabs

We selected each of the prefabs in our Prefabs folder and added a Box Collider to them. In the Game View we used the “Edit Bounding Volume” tool, as shown below, to adjust the Box Collider to make it a good fit.

To the Pizza Slice Prefab, we added a Rigid Body component and make sure to clear the option to “Use Gravity”.

We created a new script called DetectCollisions.cs and attached it to the animal prefabs. Editing this script we added the following function:

void OnTriggerEnter(Collider other)

Testing our code after this, we note that the animals disappear when they’re hit by a piece of pizza, but the pizza slices keep going. Once more change allows this code to remove the pizza slice as well:

void OnTriggerEnter(Collider other)

A Very Basic “Game Over”

We implement the most basic possible “Game Over’ message by updating the Update() function in DestroyOutOfBounds.cs as follows:

    void Update()
        if (transform.position.z > topBound)
        else if (transform.position.z < lowerBound)
            Debug.Log("Game Over!");

Now, when an animal reaches the bottom of the screen, the message “Game Over” gets printed to the Console window Unity.

Code Download

The code for this week’s project is on our GitHub, as always. 

Modelers – Coin Pile Part 3 – Week 8

This week we finished our animation by texturing the plane to look like a tabletop and adding a background image of a desert island.

We also saw how to add an add-on to Blender, namely Lily Surface Scraper.

Here are the video instructions:

Here’s a link to the finished animation:

Here’s a link to the folder where we store all our files . You’ll find a new file in there called dubloon_wip3.blend, containing everything we did this week.

Modellers – Week 8

Hi folks.

This week we started looking at texturing. Texturing is the process of taking an image, which is flat, and mapping it onto a 3D object, which generally isn’t.

UV maps are just the plan that shows which part of the texture goes to which part of the 3D model.

Unwrapping is the process of taking the 3D surface of the model and laying it flat, like peeling an orange. This flattened version of the model, when placed over the texture becomes the UV map.


The animation above illustrates the process for a simple shape as if we really were unfolding the shape manually. In reality, we just tell Blender where the seams are (where it can cut the model’s surface) and the rest can happen automatically.

Here are the video instructions for this week:

The model file can be downloaded from here.

Next week, we actually paint the model and perhaps add a logo.

Week 8, Explorers – Pen Commands

Hello Everyone,

This week we finished off our Paint Program from last week and did some more work with Pen Commands.



We didnt get to do all the code that is in the attached notes so if you want to give it a go yourself, that would be great. You can add a start and stop button and some variables.












Here are the full Pdf version of my notes from this weeks session. CDA-S8 Week 8-Pen Command.pdf

Hope to see you all this Saturday, we will be doing a great Maths Guessing Game!


Julie, Iseult, Eoin and Rauidhrí

Week 8 2019 Explorers – Paint Program

Hi everybody,

our drawing program. We made good use of costumes this week to make it look like we were dipping our paint brush in each of the different colours.

We also used a variable similarly to how we used in the Piano Game we made. We made it into a slider and then code select the Pen Size we wanted.

Here are the notes in PDF. CDA-S7-Week_08-Paint.PDF





Creators – Painting


This week we looked at making a painting program.

We started with three built in P5.js variables:

  • mouseIsPressed – true whenever the mouse button is held down
  • mouseX – contains the X position of the mouse pointer
  • mouseY – contains the Y position of the mouse pointer

We put the call to background() in the setup() function because we didn’t want to clear the background every frame. After that, in the draw() function, we just needed to draw an circle at the mouse’s position every time the mouse button was pressed.

This gave us an very basic painting program in just a few lines of code!


We then looked at the idea of a toolbar to contain buttons for selecting colours and the size of the brush.

We first need to decide where it would be (the left side of the screen) and we created a variable toolbarSize to store the width of it.

In the draw() function we then added a check not to draw an circle if we were inside the toolbar area.

We then added a new function called mouseClicked(). This is a special function name (like setup() and draw()) that P5.js will call at the appropriate time. In this case its called when the mouse is clicked (button pressed down and the released).

Colour and Sizes

We created two arrays to store a list of colours and brush sizes at the top of our script:

let colours = ['black', 'white', 'red', 'blue', 'green'];
let sizes = [5, 10, 20, 40, 80, 160];

To draw the toolbar, we made a new function called drawToolbar() and put a call to it in our draw() function. In the new function, we looped over the colours array, drawing a new button, filled with the respective colour and then another loop over sizes drawing a square with a circle inside to represent the brush size. We needed to scale those circles to make them fit inside our buttons.

Detecting Selected Button

Since everything in our toolbar was toolbarSize high, to determine what had been clicked on, we just needed to divide mouseY by toolbarSize to get the index of the button that had been clicked on. We looked at that index, if it was less than the number of colours, we must have clicked on a colour. If greater, it had to be a size (or beyond the end).

Selected colours and selected sizes were stored in two variables called currentColour and currentSize respectively and used within the draw() function when creating our circles.

Featured Artwork

Mark suggested that people draw a portrait of me to test our new program and there were some brilliant renderedings. Three people were kind enough to share theirs with me so that I could put them here. I think they’re great!


The files for this week can be found on our GitHub repository.

Week 8 2018 Explorers – Paint Program

Hi everybody,

our drawing program. We made good use of costumes this week to make it look like we were dipping our paint brush in each of the different colours.

We also used a variable similarly to how we used in the Piano Game we made. We made it into a slider and then code select the Pen Size we wanted.

Here are the notes in PDF. CDA-S7-Week_08-Paint.PDF





Explorers Week 8 – Making a Start on a Paint Program

Hi everybody,

No notes this week, I will wait until we complete the game this Saturday.

Hope you all enjoyed the visit from Medtronic, we really appreciate the volunteers coming out to see us and showing us all the really interesting and exciting things they do….and the lollipops were lovely too.

See you all next week and we will complete our Painting program



Creators – Blender


This week we did some basic modelling in Blender. Blender is a very powerful 3D graphics package that is free and open-source. It is supported across all major desktop platforms.

Blender is so large and fully featured that it can be quite intimidating to learn. Knowledge of a few shortcut keys for common operations can really improve the experience of working with the program. We were indebted to Giuliano D’Angelo’s wonderful Blender shortcut infographic for providing us with some quick reference in this regard:

Moving About and Zooming

The first thing we covered in Blender was moving about. Practically speaking, Blender requires a three button mouse to operate. In Blender the middle mouse button (MMB) is used to control the view. Used on its own, it tilts the camera. When used with the SHIFT key, it pans the camera instead. CTRL and the MMB are use to zoom, but this is also more often achieved by scrolling the mouse wheel.

Object Mode and Edit Mode

We used Blender in two modes: Object Mode and Edit Mode. The TAB key can be used to switch between these. In Object Mode we can create, select and reposition objects but we cannot do any detailed editing on them. In Edit Mode, we can do any detailed editing we require on the currently selected object. Note that selecting items in Blender is done with the right mouse button (RMB).


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