In this article, I am going to introduce how to create many rubber balls in Unity, and how to import that setup to a scene in STYLY.
- 1 Sample
- 2 Preparation
- 3 What you can do with Playmaker
- 4 Create a floor
- 5 Creating a rubber ball
- 6 Make a Prefab from the ball
- 7 Create balls with PlayMaker
- 7.1 Open PlayMaker
- 7.2 Add a FSM
- 7.3 Set a Create Object Action
- 7.4 Set a Prefab to the Create Object action
- 7.5 Changing the spawn position
- 7.6 Set the ball spawn point to pos
- 7.7 Check that the ball is correctly created at (0,2,0)
- 7.8 Set the spawn point to random
- 8 Create 100 balls
- 8.1 Sort and close the states
- 8.2 Implement the repeat process
- 8.3 Check that 100 balls are created in the scene
- 8.4 Set the parent of the ball
- 9 Set the ball color randomly
- 10 Set the balls to fall down
- 11 Set the balls to bounce
- 12 Uploading to STYLY
You can see what the scene looks like in STYLY from the URL below.
The sample project in Unity
Check the Sample Asset in WebEditor
※If you have a STYLY account, you can check the sample asset created in this tutorial from the WebEditor.
If you do not have an account, please press the button after you create one.
In this tutorial, we are going to use Playmaker to create the rubber balls.
What you can do with Playmaker
In this article, we use Playmaker for the following settings.
・Placing a object in a random position
・Changing the material of an object
・Selecting a material randomly
・Repeating a certain process using event transitions
Placing a object in a random position
You can place a object in a random position each time you execute an action by using Playmaker.
I used the following Playmaker actions
- Create Object
- Random Float
- Set Vector3 XYZ
Changing the material of an object
You can change the material of an object randomly by using Playmaker.
I used the following Playmaker actions
- Set Random Material
Repeating a certain process using event transitions
You can repeat a process by using Playmaker.
I used the event transition fucntion of Playmaker for this process
Create a floor
First, let’s create a floor.
Create a Plane object
Click the Create button in the Hiearchy, select 3D Object > Plane, and create a Plane object.
Set the Plane scale to (4,4,4).
The creation of the floor is complete!
Creating a rubber ball
Next, let’s create a rubber ball.
Create a Sphere object
Click the Create button in the Hiearchy, select 3D Object > Sphere, and create a Sphere object.
A white Sphere object is created.
Setting a color to the ball
To set a color to the ball, let’s create a material.
By using a material, we can set a color to the ball.
Right click in the Hierarchy window, and select Create > Material.
First, we are going to create a material for a blue ball, so let’s name the material “Ball_Blue”.
Setting the material color to blue
The created material is white by default, so we need to change it to blue.
Select the Ball_Blue material, and check the Emission checkbox in the Inspector window.
A color setting option will appear, so click it and set the color.
A blue material is created.
Check the material
Drag and drop the material to the Sphere, and check how the ball looks like with the material attached.
Preparing 4 more color materials
Repeat the process and create 4 more different color materials.
I created a blue, green, pink, red, and yellow material for this tutorial.
Make a Prefab from the ball
In order to use the ball with Playmaker, we need to create a Prefab from the ball.
Drag and drop the Sphere from Project to Hierarchy, and create a Prefab.
Change the name to SuperBall.
Set the SuperBall scale to (0.4,0.4,0.4).
The Prefab editing is done!
Let’s move on to PlayMaker.
Create balls with PlayMaker
Next, let’s create balls with PlayMaker.
Choose PlayMaker / PlayMaker Editor from the menu, and open the PlayMaker editor.
Open the Action Browser too.
I tend to place the windows like below for accessiblity.
Add a FSM
Select the Plane in Hierarchy, right click once in the PlayMaker window, and click “Add FSM”.
A FSM is created. An FSM is needed to run processes in PlayMaker.
It starts from the START state, then moves on to State 1, and so on.
Set a Create Object Action
For this tutorial, we are going to add a “Create Ball” process to State 1.
When you want to add a process to create an object (for this tutorial, a ball), we use the “Create Object” action.
Select State 1, and drag and drop the Create Object from the Action Browser to the State tab.
The Create Object action is registered to State 1.
This Create Object action will become a “create object” process.
Set a Prefab to the Create Object action
A Create Object action is added now, but we also have to register what object we want to create with the action.
Drag and drop the SuperBall prefab from the Hierarchy to the GameObject box, and register it.
When we play the scene after we register the SuperBall prefab, a SuperBall object is created.
The created object name will become the Prefab name + “(Clone)”.
Changing the spawn position
Next, let’s try to move the spawn position of the ball upwards.
Prepare variable “pos”
Drag and drop the “Set Vector3 Value” from the Action Browser to the space above Create Object.
Next, let’s create a variable named “pos” to store the 3-dimention position value.
The pos variable is going to be used to store the position value (x, y, z) of the ball.
Set up the pos value
Next, add (0,2,0) to pos.
Set the ball spawn point to pos
Click the Position in the CreateObject action, and choose pos from the popup menu.
Now, the ball is set to be created at the pos position(currently 0,2,0).
Check that the ball is correctly created at (0,2,0)
Click the Play button, and check the spawn position of the ball.
Set the spawn point to random
Next, let’s change the ball spawn point to be chosen randomly.
The Set Vector3 Value action we just created is no longer needed, so delete it.
Adding a Random Float action
Add a Random Float action by drag and drop from Action window. Repeat this process 2 times (Create 3 Random Float actions).
Random Float action is a process that creates a value by random.
Add a Set vector3 XYZ action
Next, add a Set Vector3 XYZ action in between RandomFloat and Create Object.
The Set Vector3 XYZ action is a process that sets the position to (X, Y, Z).
Check the registered actions
Check that your actions line up as below.
Set up the Random Float action
Set the RandomFloat action as below.
Variable X, Y, Z does not exist, so we need to create the variable by clicking “New Variable…”.
Set up the Set Vector3 XYZ action
Set the Vector3 XYZ action as below.
A position pos with random parameters is created.
Variable pos is used by the CreateObject, so the created ball will now appear in the position pos(a random position).
Check that the ball is created in a random position
Click the play button and check that the ball is created randomly.
Each time you click the play button, the ball should appear in a random position.
Create 100 balls
We completed setting up the “Create ball” process with PlayMaker.
By repeating this process 100 times, we can create 100 balls in random positions.
Sort and close the states
Sort and close the states so you can easily see the states you have created.
Implement the repeat process
The steps to repeat the processes
STEP1. Create a counter with a 0 value
STEP2. Add 1 to the counter
STEP3. Create a ball
STEP4. If the counter is smaller than 100, return to STEP2
STEP5. END the process if the counter is equal to 100
In programming, a for loop is used for repeating processes. We will create a similar process with PlayMaker.
Creating a counter variable
First, select the “Variables” tab in the PlayMaker window.
Select New Variable, and create a variable and name it “loop_counter”, and set the Variable Type to Int.
By pressing the Add button, an Int variable loop_counter is created.
Create an action that adds 1 to the counter
We will use the Int Add action to add 1 to the counter.
Drag and drop the Int Add action to the State tab.
Set “loop_counter” to Int Variable, “1” to Add.
We have completed the process to add 1 to loop_counter.
Adding an event transition
Next, let’s add a event so that if the counter value is smaller than 100, the process returns to the START state.
Events are used to set up how the process moves on depending on the conditions.
Click the Events tab in the PlayMaker window, type “スーパーバール作成”(or Create Ball) to the Add Event text box, and press Enter.
An event will be added to the Events list.
Next, right click State 1, select Add Transition > スーパーバール作成, and add a Transittion.
Drag the スーパーボール作成 to State 1, and a arrow will appear.
Now, whenever the “スーパーボール作成” event is called, the process returns to State 1.
We will use this event to choose which transition the process follows.
Create a repeat process
In order to create a repeat process, we will setup the following.
・If the loop counter is smaller than 100, the process returns to the first
・If the loop counter equal to 100, the process finishes
We use the Int Compare action to create this transition.
This action is similar to the if or if else function in programming.
Add an Int Compare action
First, drag and drop the Int Compare action from the Action browser.
Next, let’s set up the Int Compare action.
For Integer 1 set “loop_counter”, for Integer 2 set 100, for Less Than set “スーパーボール作成”.
The repeating process is complete now!
The process returns to State 1 if loop_counter value is smaller than 100, and will not (and stops) if not.
Check that 100 balls are created in the scene
Check that 100 balls are created when the play button is pressed.
Set the parent of the ball
The objects will get messed up if they are created directly under Hierarchy, so let’s use the SetParent action to set a parent.
Set the ball to StoreObject, and set the parent by setting the Game Object in SetParent.
Click the play button, and check that the created balls are created under Plane.
Set the ball color randomly
Next, let’s set the ball material randomly and make it colorful.
Add a FSM to the balls
Select the ball Prefab, and right click in the PlayMaker window, choose Add FSM.
Select State 1, and register a Set Random Material action.
The Set Random Material action selects a material randomly and sets the model’s material to it.
Register materials to the SetRandomMaterial action.
Check that the ball colors are set randomly
Click the play button and check the ball colors.
Set the balls to fall down
By attaching a Rigidbody component to the balls, the balls will fall down according to gravity.
Click the play button and check that the balls fall down.
CAUTION: If the ball positions cross over when the balls are created, the balls will burst apart.
Set the balls to bounce
Set PhysicsMaterial so that the balls bounce.
Create Physics Material
Right click upon the Project window, and create a Physics Material.
Set up Physics Material
Set up the PhysicsMaterial as below.
I set Friction to 0.0, and Bounciness to 1.0.
If you want to make the balls less bouncy, please set the Bounciness smaller.
Registering Physics Material
Register Physics Material to the SuperBall prefab.
Do the same for the floor(Plane).
You can check the settings by playing the scene.
That will be all for setting up the balls!
Uploading to STYLY
To make things simple, change the Plane object name to “SuperBallPlane”.
Drag and drop the SuperBallPlane to the Project window, and create a Prefab.
Upload the prefab to STYLY
Right click the prefab, and select Upload prefab to STYLY.
A window will popup, so wait for the upload to complete.
Once the upload is complete, a Upload succeeded message will popup.
Check in STYLY
Click the SuperBallPlane in 3D Models in STYLY, and place the prefab into your scene.