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7. August 2017


With the upcoming release of Godot 3.0, Visual Programming is now officially part of the game engine.  In this tutorial we are going to look at the basics of programming using the new Visual Programming interface.


To get started using Visual Programming, just like using GDScript or other options, you have to attach a script to an object in Godot, like so:

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In the script creation dialog, you can now select the programming language to use:

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It will now bring you to the following programming interface:

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To get started, we need to implement one of the available Godot callbacks.  These are exactly the same as GDScript and represent various different functions that will be called over time by the game engine.  To get started, in the Members section, click the following icon:

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The various different callback functions available for the selected object type are available:

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The most commonly used callbacks are _process() which is called every pass through the game loop, _ready() which is called when the object has been created, _init() which is called to create the object (think constructor), and _input() which is called when input is received.  We are going to create an exceedingly simple example here that moves our sprite each from, so select _process.  Now you should see:

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White arrows represent program flow.  Connections on the right represent output, while connections on the left represent input.  This is the entry point for our code and is going to be called each frame.  You can see we are passed a floating point value “delta” as a parameter.  Now we need to get a reference to our object, we use a “self” node for this.  You can locate notes via search:

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This gives us access to the Sprite object our script is attached.

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Now click on the blue/green ball output from the Sprite and drag a connection out, selecting Get as the option:

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This will now give you access to all of the data of a sprite object and all other inherited classes:

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Locate and select position, which is a Vector2 object.  Now lets create a variable we are going to use to define our move amount.  In the variables section, click +:

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Now right click and select Edit Variable:

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Select type as Vector2 and value of (1,0)

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Finally click the variable name and rename it to moveBy.  Now drag our newly created variable onto the canvas:

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Now we want to create an Add node and add our two vectors together, like so:

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Now we use another Self (or the same one we created earlier) and this time do a Set and select position.  We now pass in the added Vector2 result, also we attach program flow from _process, like so:

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This simple program will cause the sprite to move by 1 pixel per update.


Video Version

Programming ,

5. July 2017


There are a wealth of great add-ons for the Godot game engine, such as Add_Primitives, which adds several geometric primitives to the Godot editor, such as capsules, spheres and more.  This quick tutorial (including a video) goes step by step through the process of enabling an add-on in your Godot project.


First, you need to download the add-on you wish to enable, that or git clone it.  In this tutorial we are going to simply download it.  This link will download the add_primitives add-on zip.


Next, create a project.  Add-on’s are now located at the project level, not in the %APPDATA% folder.  In the project directory, create a folder called Addons.  In that folder, extract the zip file you downloaded earlier.  Next be sure to rename it from add_primitives-master to add_primitives, so the folder name matches the add-on name.  If you cloned using git, you wont have to perform this step.


Now load Godot.  Select the Scene Menu->Project Settings.

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Switch to the Plugins tab

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Next change Status to Active.

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And done!  If you are using the Add_Primitives add-on from this example, you should now see an additional icon in the 3D view:

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The Add-on will also be shown in your project view:

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You can watch the above process in video form below.

Programming , ,

29. June 2017


In this section of our Bowling with Game Engines series, we will be implementing our bowling game in Unity. The idea is straight forward, implement the same simple 3D game across a number of game engines.  The Unity game engine is a logical place to start, as it is perhaps the most popular game engine in use today.  We will go step by step through the process of creating our game, both in text as well as a video version available here.   I am not a regular Unity user, so please do keep in mind, a lot of what I am about to show may not be best practice!  All of the assets used in this tutorial are available for Patreons as part of the bowling game kit, along with project files and this document in PDF form.  Don’t worry, these aren’t needed to follow along.

Let’s jump in.  Fire up Unity and create a new project.  In this example I am using Unity 5.6.1, however any recent version should work.


First, let’s start by dragging all of our required assets into Unity.  Simply select all of the game assets you will be using (FBX models, textures, audio files) and drag and drop them from Explorer or Finder into the assets folder.  If you are using the Patreon assets, simply copy the contents of Raw Assets in the Unity project folder.

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Unity does an extremely good job of importing assets and you should require no additional steps.  We now have all of the assets we are going to need to create our game, let’s get started.




Creating the Title Screen


First, we are going to start by creating a simple title screen with some awful looping background music.  We will be using our default scene for the splash screen and later we will create another scene for our actual gameplay.  We start off by saving our untitled scene.  Simply select File->Save Scene As…

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I saved it as TitleScreen. You should now have a new item in your assets list:

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We now have a few setup tasks to take.  We are going to be showing our title image and this requires us to alter the Main Camera entity. In Hierarchy panel select Main Camera, then in Inspector we change Clear Flags to Don’t Clear.

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This causes our camera to no longer have perspective ( things aren’t drawn smaller the farther away they get from the camera ).  Generally an Orthographic camera is what you use when working in 2D in a 3D world. Setting Clear Flags to don’t clear simply causes the default skybox to not be drawn, we could have optionally defined a background clear colour if we preferred. 


Now in Hierarchy panel, click the Create button, select UI->Canvas.  Next, with the newly created Canvas selected, click Create again and this time select UI->Panel.  At this point we should have this hierarchy.

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Next we have to make a slight modification to our imported Titlescreen image.  Select the Tilescreen.png image file in the assets view, then in Inspector change Texture Type to Sprite (2D and UI).  Then scroll down in the Inspector and click the Apply button.

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Next select Panel in the Hierarchy view, and drag our newly created Sprite over to the Source Image section in the Image (Script) section.

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If you press Play now, you should see your Title screen in the viewport.

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Now let’s add a looping music file to our title screen.  In the Hierarchy view, select the Canvas entity.  Then in inspector scroll down and click Add Component, then Audio->Audio Source.

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In the newly created Audio Source in Inspector, drag our imported audio file over to the audio clip section.  Down below, make sure Play on Awake is set and then tick the box next to Loop.

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Ok, we now have a title screen and a sound track playing!  Good work so far… now let’s add a simple script that changes scenes on click. Let’s create our script.  Right click in the Assets area, select Create-> C# Script.

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Name it PanelScript.cs.

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Double click the newly created script file and it will open in your editor of choice.  Now enter the following code:

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.SceneManagement;

public class PanelScript : MonoBehaviour {

   // Use this for initialization
   void Start () {
      
   }
   
   // Update is called once per frame
   void Update () {
        if (Input.GetMouseButtonUp(0))
            SceneManager.LoadScene("GameScene");
    }
}


Here we are simply checking every single pass through the game loop if the Left (0th) mouse button (or touch) is clicked, and if it is, we load the scene named “GameScene”.


Hmm… guess we should make a scene called GameScene now shouldn’t we?  Once again right click the Assets panel, then select Create->Scene.

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Rename the newly created Scene to GameScene.

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We are now done with our title screen scene.  Make sure you save.  Before we open our newly created GameScene, we have one last step to perform.  In the File menu, select Build Settings…, then select Add Open Scenes.

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Now double click our newly created GameScene to open it up.  If prompted to save, do so.  Now it’s time to create our game!


Click here to continue to part two!

Programming , , ,

29. June 2017

Click here for Part One

Creating the Game Scene


Now it’s time to get to work on creating the game itself.  Start off by dragging BowlingLane into the scene.

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Now move the lane so it’s at position (0,0,0) in the Inspector under the Transform component.

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One thing I noticed is the Normal map is way too strong.  Select the Bowling Lane material (either in the Materials panel, or drill down to it).  Dial back the Normal Map strength from 1.0 to 0.2.

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We are almost done with our bowling lane.  The final thing we need to do is add a Collision Shape to it, so the rest of the stuff in our game world will interact with it properly.  With the BowlingLane selected, click Add Component->Physics->Box Collider

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The nice thing with Unity is, it will automatically shrink wrap the collider geometry to match your mesh, so you should have to do no additional work!

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So, that’s it for the lane, now time to create the Bowling pins.  Simply drag the Bowling Pin into the scene:

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Hmmmm… pretty dark. What’s going on here?  Well, right now we are getting our lighting from the Directional Light in our scene.

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We don’t want to mess around with advanced lighting, so instead right click and get rid of it. Now lets set up Ambient lighting instead.  Select Window->Lighting->Settings

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Change Environment Lighting->Light Source to Color, then select the Ambient Color as white:

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Now our scene will have universal consistent lighting:

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Now it’s time to add some physics to our pin.  Once again we have to make a collision object component, but we also need to create a RigidBody component.  Add a Box collider just like before.  Then add another Component and select Physics->Rigidbody

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The default settings are about right, so there is nothing else we need to do here.


The final thing we need to do with our pin is apply a tag to it so we can locate it using code later. With the Pin selected, in the Inspector at the top drop down the Tag drop down and select Add Tag…

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Click the + Icon, then in the resulting text box enter “Pin” then Save.

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Now select the Pin again, and in the Tags list, select Pin which should now be an option.

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Now we simply need to create 4 ( or 9… depending your bowling preferences ) clones of our pin. Select the BowlingPin in the scene graph, right click and select Duplicate.  This will create a copy with all of the settings and components defined. 

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After duplicating, position the pin and repeat the process until you have enough pins.

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Click here to continue to part three.

Programming , , ,

29. June 2017


Click here to go back to Part Two.


Next, we need to create a bowling ball.  Instead of importing a 3D mesh, we are going to create one.  Select Game Object->3D Object->Sphere.

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Once created, rename it to BowlingBall.

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While we are here, create a new Tag called Ball and assign it to our object.


Let’s create a material for our Bowling ball.  Right click assets panel, select Create->Material.  Rename the newly created material BowlingBall.  Pick the color of your bowling ball with the box to the right of Albedo.  For shine add a small amount of Metallic as well.

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Now simply drag the newly created material over to our Bowling Ball in the scene.


We also need to attach physics to our bowling ball.  This time it’s using a Sphere Collider.  This is also a rigid body, but this time we increase the mass to 3.

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We are going to be putting all of the logic in our bowling ball.  One thing we are going to need to do is play audio when our ball hit’s a pin. We will add this logic later, but the audio source needs to be somewhere, so why not the bowling ball. We actually covered this process earlier when we added audio to our title screen.  Simply add an Audio Source component to the ball then attach the Hit.wav file, like so:

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Tick off the Play on Awake checkbox.


Now its time to add some scripting to our game to control input and to deal with physics collisions when they happen. Right click the Assets panel and create a new script like we did earlier. Rename it BowlingBall.cs and drag it onto our BowlingBall object.  Now double click our script and enter the following code:

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class BowlingBall : MonoBehaviour
{
    public float force;
    // Use this for initialization
    private List<Vector3> pinPositions;
    private List<Quaternion> pinRotations;
    private Vector3 ballPosition;
    void Start()
    {
        var pins = GameObject.FindGameObjectsWithTag("Pin");
        pinPositions = new List<Vector3>();
        pinRotations = new List<Quaternion>();
        foreach (var pin in pins)
        {
            pinPositions.Add(pin.transform.position);
            pinRotations.Add(pin.transform.rotation);
        }

        ballPosition = GameObject.FindGameObjectWithTag("Ball").transform.position;
    }


    // Update is called once per frame
    void Update()
    {
        if (Input.GetKeyUp(KeyCode.Space))
            GetComponent<Rigidbody>().AddForce(new Vector3(0, 0, force));
        if (Input.GetKeyUp(KeyCode.LeftArrow))
            GetComponent<Rigidbody>().AddForce(new Vector3(1, 0, 0), ForceMode.Impulse);
        if (Input.GetKeyUp(KeyCode.RightArrow))
            GetComponent<Rigidbody>().AddForce(new Vector3(-1, 0, 0), ForceMode.Impulse);
        if (Input.GetKeyUp(KeyCode.R))
        {
            var pins = GameObject.FindGameObjectsWithTag("Pin");

            for (int i = 0; i < pins.Length; i++)
            {
                //collision.gameObject.transform.parent.gameObject.tag
                var pinPhysics = pins[i].GetComponent<Rigidbody>();
                pinPhysics.velocity = Vector3.zero;
                pinPhysics.position = pinPositions[i];
                pinPhysics.rotation = pinRotations[i];
                pinPhysics.velocity = Vector3.zero;
                pinPhysics.angularVelocity = Vector3.zero;

                var ball = GameObject.FindGameObjectWithTag("Ball");
                ball.transform.position = ballPosition;
                ball.GetComponent<Rigidbody>().velocity = Vector3.zero;
                ball.GetComponent<Rigidbody>().angularVelocity = Vector3.zero;
            }
        }
        if (Input.GetKeyUp(KeyCode.B))
        {
            var ball = GameObject.FindGameObjectWithTag("Ball");
            ball.GetComponent<Rigidbody>().velocity = Vector3.zero;
            ball.GetComponent<Rigidbody>().angularVelocity = Vector3.zero;
            ball.transform.position = ballPosition;
        }
        if (Input.GetKeyUp(KeyCode.Escape))
        {
            Application.Quit();
        }
    }
    private void OnCollisionEnter(Collision collision)
    {
        if (collision.gameObject.tag == "Pin")
            GetComponent<AudioSource>().Play();
    }}

We publicly expose the Force value, which is the amount of energy to apply along the Z axis when we throw the ball.  Since it is public, it’s settable in the editor as a property in the script component.

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And done!


The Video

Programming , , ,

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