3-Handed Laser Shuffle

I recently competed in a game jam on Itch.io. The requirements were a 128×128 resolution, four colors, one weekend, and a theme of “break out.” So I made this. The controls take some getting used to. It’s intentionally a bit awkward, and requires some practice switching among three controls with only two hands. WASD controls the red laser. TFGH controls the green laser. The arrow keys control blue. Try to destroy the matching blocks before they get too close. Every 100 blocks cleared gives you a power-up that you can use with SPACE. This pauses block movement for a few seconds.

3-Handed Laser Shuffle won first place in the Mini Jam, among 20 entries. Try it out!

Creating a Circuit in Unity

During a recent game jam, my team made a game called Elevator Circuit. The game is now available on for free on Itch: https://tykenn.itch.io/elevator-circuit. The objective is to complete a circuit by moving elevators holding circuit segments, aligning them into a complete path. It currently has five short puzzles with more to come. My biggest role in the project was to program the circuit system.

The idea was that any segment without a path to a generator would be red. A segment with a path from one side, but not a path from the other is yellow. When there is a path to a battery from both sides, current can actually pass through the segment, it turns green. I used Procedural Lightning to indicate that the connectors of two segments are close enough to be connected (It happens even when the two segments are not connected to a battery, but we needed some kind of feedback).

My first (failed) attempt

I made a script for each connector that checked for other connectors to enter and exit its trigger area. It then registered the segment of the other connector to current segment. The connector then told the segment to update its material by recursively checking its neighboring segments, and then its neighbor’s neighbors, until it either dead-ends, loops , or reaches a battery. All the segments along that path would update their materials accordingly. I soon ran into all sorts of race conditions and edge cases. The lightning would correctly connect segments, but the colors of the segments would be wrong half the time. So, I scrapped that and tried something new.

Working from the battery to the segment.

Since there would only ever be a handful of segments in any stage, it would not be too expensive to check for changes every frame. I kept what I had before with each connector registering other segments to its own segments, but instead of updating the materials only during a connection change, the battery would “pulse” every frame. Going recursively to each connected segment from the battery, it would mark the visited segments as “connected” either from the left or right, depending on where the pulse came from. The segments would then all update their materials accordingly, the frame would render, and then the connections would reset for the next pulse.

Here is the script that goes on the individual connectors:

using UnityEngine;

public class CircuitConnector : MonoBehaviour {

    public bool isLeft;
    CircuitSegment segment;

    private void Awake()
    {
        //Expect CircuitSegment script to be on parent.
        segment = transform.parent.GetComponent();
    }

    //Make a connection
    private void OnTriggerEnter(Collider other)
    {
        CircuitConnector otherCon = other.GetComponent();
        if (otherCon != null && otherCon != this)
        {
            //Register connection to segment
            if (isLeft)
            {
                segment.leftSegment = otherCon.segment;
            }
            else
            {
                segment.rightSegment = otherCon.segment;
            }
            //Code for anything else to do during a
            //connection, like instantiate lightning
        }
    }

    //Lose connection
    private void OnTriggerExit(Collider other)
    {
     
        CircuitConnector otherCon = other.GetComponent();
        if (otherCon != null && otherCon != this)
        {
            //Unregister segment
            if (isLeft && segment.leftSegment == otherCon.segment)
            {
                segment.leftSegment = null;
            }
            if (!isLeft && segment.rightSegment == otherCon.segment)
            {
                segment.rightSegment = null;
            }
        }
    }
}

And here is the script that goes on the circuit segment:

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

public class CircuitSegment : MonoBehaviour {

    [HideInInspector]
    public CircuitSegment leftSegment;
    [HideInInspector]
    public CircuitSegment rightSegment;
    [HideInInspector]
    private List meshesToPaint;

    //Usually only one of these in the scene at a time
    public bool hasBattery;

    //I used a red, yellow, and green material
    public Material deadMaterial;
    public Material oneWayMaterial;
    public Material poweredMaterial;

    //Optional event for receiving/losing power,
    //like opening and closing a door
    public UnityEvent powerEvent;
    public UnityEvent losePowerEvent;

    //Resets every frame, set by pulses
    private bool leftPowered = false;
    private bool rightPowered = false;

    //Does not reset, decided after pulsing finishes
    private bool powered = false;

    //only true during a pulse for checking
    //for loops
    private bool pulsing;

    private void Awake()
    {
        //Register all the meshes I want to paint.
        //I tagged all of them with "Wire"
        meshesToPaint = new List();
        foreach (Transform child in transform)
        {
            if (child.tag == "Wire")
            {
                meshesToPaint.Add(child.GetComponent());
            }
        }
        UpdateMat();
    }

    public void Update()
    {
        //Handle events for gaining and losing power.
        if (!powered && leftPowered && rightPowered)
        {
            powered = true;
            powerEvent.Invoke();
        }
        else if (powered && !(leftPowered && rightPowered))
        {
            powered = false;
            losePowerEvent.Invoke();
        }

        //Reset power
        leftPowered = false;
        rightPowered = false;
    }

    //Don't pulse until everything is reset from Update()
    private void LateUpdate()
    {
        //Only segments with batteries start a pulse
        if (hasBattery)
        {
            if (leftSegment != null)
                leftSegment.Pulse(this);
            if (rightSegment != null)
                rightSegment.Pulse(this);
        }
    }

    //Recursive function for deciding connections to batteries
    public void Pulse(CircuitSegment from)
    {
        //If a segment has already been visited in a pulse, it
        //must have looped.
        if (!pulsing)
        {
            pulsing = true;
            if (from == leftSegment && from == rightSegment)
            {
                //Handle edge case of a circuit with only two segments
                leftPowered = true;
                rightPowered = true;
            }
            else if (from == leftSegment)
            {
                leftPowered = true;
                if (rightSegment != null)
                    rightSegment.Pulse(this);
            }
            else if (from == rightSegment)
            {
                rightPowered = true;
                if (leftSegment != null)
                    leftSegment.Pulse(this);
            }
        }
        UpdateMat();
        pulsing = false;
    }

    // Update is called once per frame
    public void UpdateMat() {
        Material mat;
        if (hasBattery)
        {
            //Batteries work a little different. Never red.
            if (leftSegment != null && leftSegment.leftPowered && 
                rightSegment != null && rightSegment.rightPowered)
            {
                mat = poweredMaterial;
            }
            else
            {
                mat = oneWayMaterial;
            }
        }
        else
        {
            if (leftPowered && rightPowered)
            {
               mat = poweredMaterial;
            }
            else if (leftPowered || rightPowered)
            {
                mat = oneWayMaterial;
            }
            else
            {
                mat = deadMaterial;
            }
        }

        //Apply the material to every assigned mesh
        foreach (var rend in meshesToPaint)
        {
            rend.material = mat;
        }
    }
}

Now, in Unity, make a GameObject and attach the CircuitSegment script. Then add some meshes that you want to change colors. Tag them as “Wire” and make the CircuitSegment object its parent. Then also make two connectors, attach the CircuitConnector script to each, and mark one as isLeft. Make them also children of the segment. Now, if you have some object you want a complete circuit to trigger, like opening and closing a door, make a new script with two public methods such as Open() and Close(). On the segment that powers the object, you can assign those methods in the inspector through the Power Event and Lose Power Event.

Ten Super Helpful Unity Assets

As I’ve been working on Nebula Gladiator VRFly Around and Zap Aliens,  and Fail to Win, I’ve relied heavily on the Unity Asset Store. It is a great way to avoid reinventing to wheel. Unity itself all the basic tools you need (physics, animation, etc.), but to get a good starting point for your game, it is pretty much essential to add some packages from the Asset Store. Many of the packages cost a small amount (I have five packages ranging between 5 and 20 dollars), but many are free as well. Anyway, I’ve played around with a lot of Unity packages and found a few to be particularly useful. I’ve limited this list to just code and effect packages, since those tend to be more generally applicable.

1. Ragdoll and Transition to Mecanim

This is what I’m using for the ragdoll transitions in Fail to Win. In a 3D game where your avatar can get hurt (which is almost all of them), using ragdolls is a lot easier than creating death animations. It also tends to respond better to forces than pre-set animations. This tool by BzSoft, makes it even easier by automatically turning a character into a ragdoll when, for example, you fall from a really high ledge. Then, when things calm down, the avatar get back onto his or her feet. Also, it’s free.

2. Procedural Lightning

I am using this to do the zapping part of Fly Around and Zap Aliens. I used to have a simpler procedural lightning effect, but this looks way better. It has a surprising amount of configuration, so if you need anything that even somewhat resembles lightning or sparks, you can probably use this. Despite that, it is super easy to set up. It only costs $9.

3. Log Viewer

This solved a frustrating problem. I tested everything in the Editor, and it worked great. Then I made a build and deployed it to my phone. I opened it up to find the game broken. I could dig around and find the log file, but finding problems that way takes more time, and you may have to dig through a lot more. I then added this to my project and could open the log from my phone with a simple circle swipe gesture. It looks like the Unity console. It also displays the frame rate, memory usage, and other stats. This could be super useful for collecting information from beta testers. This package is free.

4. ProBuilder

So, I’m not much of an artist, and even if I was, I wouldn’t want to go into Blender or Maya and design a level just to test a simple idea. So I spent a lot of time carefully aligning primitives (mostly cubes) into rooms. The Standard Assets Prototyping package helped a little, but it still lacked the kind of control I needed. ProBuilder is a free package that lets you model directly withing the Editor. Granted, it would not be ideal for anything as complex as character design, but it is fantastic for level design.

5. FinalIK

This is the priciest package I’ve listed so far as $90, but if your game involves a lot running around and climbing on stuff, this may make your animations look a thousand times better. I got tired of having floating feet when walking on slopes, so I was really excited to finally have a way to fit my animations seamlessly to the stage just like in AAA games. This package does a lot more than stick feet to floors. Climbing, opening doors, pressing buttons, and pretty much anything else that involves animation and an avatar’s surrounding are going to look a lot better with FinalIK. I’m even using it in Fly Around and Zap Aliens, although I had to be sure to turn it off every time you become a ragdoll; otherwise, weird stuff happens.

6. Mesh Slicer

Another BzSoft package that makes it easy to create a more fun game. It lets you cut a mesh along a plane, or even along the path of a knife (or sword). It is a super satisfying effect in VR. That’s why I added it to Nebula Gladiator VR. A VR sword isn’t going to meet any resistance except maybe when a family member or roommate walks through the living room at the wrong time and gets hit with a controller, so a VR sword should cut cleanly through anything it hits. It got even better when I wrote a simple script that forces the pieces to fly away from each other after being cut.

7. Head Look Controller

I’m amazed this package still works, since it hasn’t been updated since 2010. It is free, and simply makes people look at stuff. There may be some other similar packages that do the same thing and are more up to date, but most of the time, this package should be all you need. It is super easy to set up and is another subtle effect that really makes a game look so much better.

8. MK Glow

It is a nice-looking glow effect that can be added either to individual objects or to a whole scene. I’m probably going to add it to Fly Around and Zap Aliens soon. I’ve played around with it before, and it is really easy to set up. They even have a free version. The upgraded version is only $10, and offers some extra control, but the free version is already super useful.

9. Unity Particle Pack

This is a Unity Essentials pack, so there’s a good chance you have already been using it, but I had to list it here because of how useful it is. I am using its explosions in Fail to Win, but a lot of its more subtle effects like dust and sparks can add the right kind of detail to a game. Most games are going to have a good reason to use at least one of those effects.

10. Post Processing Stack

Another Unity Essentials package, but worth mentioning. When used right, this could help make your game look less like an obvious computer rendering and more like a cinematic masterpiece. I discovered it doesn’t work so well on mobile, but on other platforms, it helps give the finishing touches.

A Final Note

Many of these tools were things I discovered when I was noticing details in my games that made them seem like ugly amateur indie games instead of modern quality masterpieces. Thank you to all the creators of these tools. The asset store is a fantastic resource. I’ve both sold and purchased tools on the asset store, and the system is great. I, of course, haven’t tried everything on the asset store (there are thousands!), so I’m curious if any of my Unity gamedev readers here have used a Unity package they consider a must-have. If so, please share in the comments below.

How to model procedurally in Unity3D

Unity3D is not a modelling tool. It is usually easier to design artwork in an animation program like Blender or Maya, and then import them into Unity. However, for some things, especially procedurally generated content, you’ll need to dive into the drawing tools Unity provides in its libraries.

Note: This tutorial assumes you have a basic knowledge of the Unity Editor. If you do not, you should first go through Unity’s beginner tutorial.

First, create a new scene in Unity. Go to GameObject > 3D Object > Cube to add a new object to the scene, and position it at the origin. Then, in the Project window, go to Create > C# Script. Name the SimpleMesh, and then double click it to launch Visual Studio. Now we are ready to start coding.

We’ll begin by creating a Mesh object. This is what hold the shape of our object. We make a mesh by creating a bunch of 3D vertices and then connecting these vertices to make triangles. Unity does not have a built-in way of making pyramids, so we’ll make one with our SimpleMesh script. I’ll show the code and then explain:

using UnityEngine;

public class SimpleMesh : MonoBehaviour {

    void Start () {

        Vector3[] verts = new Vector3[16];
        //base
        verts[0] = new Vector3(-1, 0, -1);
        verts[1] = new Vector3(-1, 0, 1);
        verts[2] = new Vector3(1, 0, 1);
        verts[3] = new Vector3(1, 0, -1);

        //front wall
        verts[4] = new Vector3(-1, 0, -1);
        verts[5] = new Vector3(0, 2, 0);
        verts[6] = new Vector3(1, 0, -1);

        //back wall
        verts[7] = new Vector3(1, 0, 1);
        verts[8] = new Vector3(0, 2, 0);
        verts[9] = new Vector3(-1, 0, 1);

        //left wall
        verts[10] = new Vector3(-1, 0, 1);
        verts[11] = new Vector3(0, 2, 0);
        verts[12] = new Vector3(-1, 0, -1);

        //right wall
        verts[13] = new Vector3(1, 0, -1);
        verts[14] = new Vector3(0, 2, 0);
        verts[15] = new Vector3(1, 0, 1);

        //order the indices of verts in patterns
        //to make triangles
        int[] tris = new int[18] { 3,2,0,2,1,0,4,
                     5,6,7,8,9,10,11,12,13,14,15};

        //add the vertices and triangles to a new mesh
        Mesh mesh = new Mesh();
        mesh.vertices = verts;
        mesh.triangles = tris;

        //Assign the mesh to the MeshFilter component
        GetComponent().mesh = mesh;
    }
}

Everything will happen inside the Start() method so it will happen once when we play the game. This is what the script does:

  1. Create an array of 3D vectors to store our vertices. Our pyramid will have five vertices: the top and each of the four corners. Many of these vertices are duplicated in our array. This is because we want hard edges. Shared vertices mean there will be a smooth edge, like the surface of a sphere. Duplicated vertices mean it will draw a hard edge like a corner. We’ll come back to that later.
  2. Create and array to store triangle information. This may seem like a strange list of numbers, but each corresponds to an index in the triangles array. Every three numbers represent one triangle connecting vertices counter-clockwise. So the first triangle connects vertices 3, 2, and zero, the second connects 2, 1, and zero, and so forth.
  3. Create a new Mesh object. This stores both our vertices and triangles.
  4. Assign the new mesh to the MeshFilter. This component should already be on our object, since we are creating it from a Cube. It will also use the material already assigned to the Cube. The material tells Unity how to draw the shape on the screen based on textures and lighting. Materials can also be generated, but that is outside the scope of this tutorial.

Assign the SimpleMesh script to the cube object. If you press play, you should see something like this:

pyramid

You may need to adjust the camera position or pause the game to get a better view. The shape is right, but it still looks kind of strange. There is nothing to distinguish the edge, and the lighting is weird. This is because we have not assigned normals. Normals are direction vectors that are supposed to point away from the object. There is one for each vertex. When light hits an object, it reflects more light if it hits directly than if it hits at an angle. The normals give Unity a reference to decide what is considered direct.

normal_explanation

Normals are why we duplicated vertices. Unity blends between the normals to get smooth curves, like in the top diagram. At a hard edge, though, where would the normal point? With two vertices, we can have two normals, one pointing away from each wall that meets at that corner. There is no blending because we have two separate surfaces.

Fortunately, for a shape as simple as this, the normals can easily be calculated. Add this inside the Start() method after everything else:

mesh.RecalculateNormals();

That’s it!. Press play and you should see a pyramid that looks something like this:

pyramid2

Radar Arrows

Radar Arrows make it easier for players to find things (enemies, destinations, other players, etc.). If the object is on-screen, you can have an arrow of a constant size hover above that object, making it easier to spot. If the object is off-screen, the arrow will appear on the edge of the screen, pointing to where the object appears off-screen.

Check it out at the Unity Asset Store.

Or try out the web demo.