Importing the Base Unity Package

We’ll use the same VR Playground project here, as it already comprises all the required Tilia Packages and the entire VRTK SETUP created with this book. In this case, we’ll utilize only those prefabs required to build our minigame.

As part of the downloads that come with this book, you’ve been provided a Unity package file called “Garden Path” that you need to download and import into your project. Note that it may take a while to import. Once the import is complete, select the “Assets” folder and then navigate to and expand the “Garden Environment” folder and then expand the “Game” folder within it. Now, launch the Garden scene. You may need to rotate your garden path around in the scene view so that it’s facing forward, as shown in Figure 22-1.

The garden path you see in Figure 22-1 has been populated with 37 game objects that the player needs to pick up by rolling a Ball onto them. Some of these game objects have a basic animation on them and some don’t. However, each game object on the garden path is fitted with either a Sphere or Box Collider. The colliders on the game objects have both been set up as a Trigger. Setting them as a Trigger is vital to the development of the core game mechanic. Select any game object from within the Scene tab, and in the Inspector, you’ll see that the Is Trigger property in its collider component has been checked, as shown in Figure 22-2.

Now, you need to create a new Tag named Grabbable that will be used to identify grabbable game objects in the Scene. From the main menu, go to Edit ➤ Project Settings , and from the pane on the left, select the item Tags and Layers . Expand the “Tags” section and click the plus symbol in its bottom right corner. For the New Tag Name property , type in “Grabbable,” and click save. Now, close the Project Settings dialog, see Figure 22-3.

We next need to set up the VRTK-provided Collision Tracker component on each of the 37 obstacle game objects in your garden path. Let’s first set up this component on the Fruit Apple obstacle. To do so, expand the Environment game object in the hierarchy, then select the Fruit Apple game object, and in the Inspector, click the Add Component button and add a new Collision Tracker component. Set its Emitted Types property to Trigger. Set its States to Process property to Enter, which indicates that you’re looking for an On Trigger Enter Collision to occur against your Fruit Apple Obstacle. Once this On Trigger Enter state has been reached, the Collision Started Event listed in the “Collision Event” section will be triggered. Here you need to set the Fruit Apple obstacle game object’s Tag value to Grabbable. Let’s set this up.

Click the plus symbol located in the bottom right corner of the Collision Started Event to add an event listener. Then, drag and drop the Fruit Apple obstacle game object into this event listener box. For this function, select Collision Tracker, String, Tag. In the text box below, type in “Grabbable.” Ensure that you spell it exactly as shown in Figure 22-3.

We have now ensured that the moment the Ball collides with the Fruit Apple obstacle, its Tag will be set to Grabbable, as shown in Figure 22-4. The Collision Tracker component works like the On Trigger event that you use in coding to determine if one object has collided with another and what action should be taken in response. With the Collision Tracker component placed in each obstacle game object, the moment the Ball collides with any obstacle, its Collision Tracker component’s Collision Started event will be triggered, setting the Tag of the obstacle that collided with the Ball to Grabbable. This Tag value is later used by a rule that allows the obstacle to attach itself to the Ball, as we will see shortly.

Now it’s time for to set up the Collision Tracker component on the remaining 36 obstacle game objects in the Scene. With the Fruit Apple game object still selected in the hierarchy, copy its Collision Tracker component from within the Inspector. Select all the remaining obstacle game objects in the hierarchy, starting with Fruit Orange and going all the way down to Gate (3). Then, click the vertical ellipsis button next to the Transform component , and in the context menu that pops up, select Paste Component as New. This will set up the Collision Tracker component for each of the obstacle game objects you selected, see Figure 22-5.

Now, in the Environment game object, expand the World game object and then expand Map Objects. It is within Map Objects that the remainder of your obstacle game objects reside. Select only those obstacle game objects that are active, as they are the ones available in the Scene. In total, there are 14 active obstacle game objects in Map Objects that you need to select. Once you have selected all of them, click the vertical ellipsis button next to the Transform component. In the context menu that appears, select Paste Component as New. This will set up the Collision Tracker component on these remaining 14 obstacle game objects, see Figure 22-6.

You may have noticed that you’ve also been provided with the Ball game object as a sphere in the hierarchy. Click on this Ball game object, and in the Inspector, you’ll see that its Transform Scale valuesc have been set to 0.5 across all axes. Also, a Football Net material has been applied to it, giving it a netted ball effect. It has been fitted with a Sphere Collider, which is not a Trigger, whose Radius of 0.5 ensures that it encompasses the Ball well. It also has a Rigidbody component with a Mass of 1 and a Drag and Angular Drag of 0.5. The Use Gravity property has been checked, and the Collision Detection property has been set to Continuous, as shown in Figure 22-7. This is the basic setup you’ve been provided.

Setting Up the VRTK Prefabs

In this section, we’ll create prefabs of certain game objects in the Demo scene that are required by the Garden scene to set up its VR functionality. Let’s start by launching the Demo scene and creating a new folder in the “Assets” folder and naming it “Prefabs.” Then, with the Demo scene open, expand the VRTK SETUP game object, and drag and drop its child game object, VRTK CAMERA RIGS SETUP, from within it to the newly created “Prefabs” folder. You now have a VRTK CAMERA RIGS SETUP prefab that can be used in any other scene of your project.

Next, let’s create the remaining prefabs that will be required in the Garden scene of our minigame. With the VRTK SETUP game object still expanded, locate the VRTK INPUT CONTROLLERS game object in the hierarchy and drag and drop it into the “Prefabs” folder. Then, drag and drop the VRTK PSEUDOBODY game object into this folder. Select the VRTK PSEUDOBODY prefab in the same folder, and click the Open Prefab button in the Inspector. With this prefab opened, select the Trackers Pseudo Body game object in the hierarchy. In the Inspector, you’ll see that the property values for its Source, Offset, and Ignored Game Objects (Elements 0 through 5) have been lost. You’ll need to set these up again once you drop this prefab into the Garden scene, see Figure 22-8. This is because Unity won’t allow you to reference scene game objects in a prefab. These are all the prefabs required from within VRTK SETUP for the Garden scene.

Within the Demo scene, select and expand the Button Input Actions game object in the hierarchy. Drag and drop the Thumbstick Horizontal Axis Input game object into the “Prefabs” folder. When asked whether you want to create an original prefab or a variant of this prefab, select Original Prefab. Then, drag and drop the Thumbstick Vertical Axis Input game object into the “Prefabs” folder. When asked whether you want to create a new original prefab or a variant of this prefab, select Original Prefab.

Then, click either the Thumbstick Vertical Axis Input or Thumbstick Horizontal Axis Input prefab in the “Prefabs” folder, and then click the Open Prefab button in the Inspector. You’ll see that the Activated event settings have been lost. You’ll need to recreate both of these prefabs once you drop them into the Garden scene, see Figure 22-9. All this Activated event did was to play the Teleporting animation that goes with the Hand Proto Left game object.

Finally, as we’ll be using just one of the Slide movements for locomotion, we’ll set up this locomotion method from scratch directly in the Garden scene. Let’s start setting up the various VRTK prefabs in the Garden scene.

Launch the Garden scene. With the Garden game object selected in the hierarchy, navigate to the Assets ➤ “Prefabs” folder, and drag and drop in the VRTK CAMERA RIGS SETUP prefab. With the VRTK CAMERA RIGS SETUP game object selected, set its Transform Position property values as follows: X = 5; Y = 0; and Z = -38. This ensures that you start out positioned behind the Ball.

Now, expand the VRTK CAMERA RIGS SETUP game object in the hierarchy and deactivate the Camera Rigs, Oculus Integration and Camera Rigs, Spatial Simulator game objects. Activate the Camera Rigs, Unity XR game object. By setting this up, you can test your game using either your Oculus or HTC Vive headset .

After that, ensure that you have the Garden game object selected in the hierarchy, and then drag and drop in the VRTK INPUT CONTROLLERS prefab. You’ll need to unpack the VRTK INPUT CONTROLLERS game object before deleting some of its child game objects. Expand this game object and delete the child game objects Mouse Input, Keyboard Input, and Input Unity Input Manager Xbox Controller, as you’ll be targeting only the Oculus and HTC Vive controllers.

Next, drag the VRTK PSEDUDOBODY prefab into the hierarchy, making it a child of the Garden game object. Expand the VRTK PSEDUDOBODY game object in the hierarchy, and select its Trackers Pseudo body child game object. You need to set up all its missing property values in the Inspector. For its Source property, drag and drop in the Headset Alias game object. For its Offset property, drag and drop in the Play Area Alias game object. For the Ignored Game Objects, Element 0 property, drag and drop in the Interactions Interactor Left game object. For the Ignored Game Objects, Element 1 property, drag and drop in the Interactions Interactor Right game object. For the Ignored Game Objects, Element 2 property, drag and drop in the Custom Hand Left game object. For the Ignored Game Objects, Element 3 property, drag and drop in the Hand Proto Left game object. For the Ignored Game Objects, Element 4 property, drag and drop in the Custom Hand Right game object. Finally, for the Ignored Game Objects, Element 5 property, drag and drop in the Hand Proto Right game object, see Figure 22-10.

Your pseudo-body has now been set up.

Next, with the Garden game object selected, drag and drop the Thumbstick Horizontal Axis Input and Thumbstick Vertical Axis Input prefabs into the hierarchy, as shown in Figure 22-11.

Then, select both the Thumbstick Horizontal Axis Input and Thumbstick Vertical Axis Input game objects in the hierarchy, and populate their Activated event in the Inspector. Following that, drag and drop the Hand Proto Left game object into this event listener box. For the function, select Animator, Play String from within the “Static Parameters” section. Type “Teleporting” into the box below that, as shown in Figure 22-12, to specify that this is the animation that needs to play.

Next, in the “Packages” folder of the Project tab, locate the Tilia Locomotors Axis Move Unity package and expand its “Runtime/Prefabs” folder. Drag and drop the Locomotors Axis Move Vertical Slide Horizontal Snap Rotate prefab into the hierarchy, making it a child of the Garden game object.

Now, select the Locomotors Axis Move Vertical Slide Horizontal Snap Rotate game object in the hierarchy, and let’s set up its properties in the Inspector. Drag and drop the Thumbstick Horizontal Axis Input game object into the Horizontal Axis property of its Axis Move Facade component ; drag and drop the Thumbstick Vertical Axis Input game object into the Vertical Axis property of this component; drag and drop the Play Area Alias game object into its Target property ; drag and drop the Headset Alias game object into its Forward Offset property ; drag and drop in the Headset Origin game object into its Rotation Pivot property; and finally, Drag and drop the Scene Cameras game object into its Scene Cameras property .

You now have your Sliding locomotion set up, see Figure 22-13.

We now need to capture button input actions for the horizontal and vertical movements of our Right Controller’s Thumbstick. This will enable us to move the Ball in different directions during game play. We’ll capture these inputs for the Oculus and HTC Vive controllers.

To do this, with the Garden game object selected, let’s create a new empty game object in the hierarchy and rename this game object “Thumbstick Horizontal Axis Right.” Then, let’s add a Float Action component to this game object, and set its Sources size property to 2, which will provide you with two Element slots. Now, select the Thumbstick Horizontal Axis Right game object in the hierarchy, and duplicate it and rename the copied game object “Thumbstick Vertical Axis Right.”

Now, expand the VRTK INPUT CONTROLLERS game object in the hierarchy, and then expand the Input Unity Input Manager Oculus Touch Right Controller game object until you reach its Right Thumbstick game object, which you need to expand, too. You’ll be capturing input for the horizontal and vertical axis movement of the Right Thumbstick.

Next, expand the Input Unity Input Manager Open VR Right Controller game object until you reach its Right Trackpad game object, which you also need to expand. You’ll be capturing input for the horizontal and vertical axis movement of the Right Trackpad.

Now, in the hierarchy, select the Thumbstick Horizontal Axis Right game object. Drag and drop the Right Thumbstick Horizontal Axis [4] game object from the hierarchy into the Element 0 slot. Then, drag and drop the Right Trackpad Horizontal Axis [4] game object into the Element 1 slot, as shown in Figure 22-14.

Now, in the hierarchy, select the Thumbstick Vertical Axis Right game object. Drag and drop the Right Thumbstick Vertical Axis [5] game object from the hierarchy into the Element 0 slot. Then, drag and drop the Right Trackpad Vertical Axis [5] game object into the Element 1 slot, see Figure 22-15.

You now have two intermediary game objects that capture the horizontal and vertical axis movements the Thumbstick and Touchpad. You’ll use values for this movement to move the Ball in different directions during the game.

Enabling Obstacle Objects to Attach to the Ball

Upon rolling the Ball onto any obstacle game object in the Scene, you must ensure that the object attaches itself to the Ball. To achieve this behavior, we’ll set up a Mutators Object Follower. You’ll recall that we learned to use the Mutators Object Follower prefab when we had our Holsters follow our Play Area Alias. We also used the Offset Object property to offset the Holsters a bit in front of the Play Area. We’ll apply the same strategy here, with the Ball becoming the Source game object and each of the 37 obstacle game objects becoming a Target of the Mutators Object Follower prefab. Each of these 37 game objects contains a child Offset game object that has been assigned a random Transform Position value. Each child Offset game object with an assigned Transform Position value allows each obstacle game object to attach itself to the Ball in a slightly different position.

Let’s set this up now. Expand the “Packages” folder in the Project tab, locate the Tilia Mutators Object Follower Unity package, and expand it until you reach its “Prefabs” folder. Drag and drop the Mutators Object Follower prefab into the hierarchy, making it a child of the Garden game object, and rename the Mutators Object Follower game object, “Mutators Object Follower Obstacles.”

With the Mutators Object Follower Obstacle game object selected in the hierarchy, ensure that its Object Follower component has been expanded in the Inspector. Set its Sources Elements property size to 1, which will provide you with an Element 0 slot. Then, drag and drop the Ball game object from the hierarchy into this slot. The Ball is now the Source object that the obstacles will follow, see Figure 22-16.

With the Mutators Object Follower Obstacles game object still selected in the hierarchy, set the Targets Elements property size to 37. This will provide you with 37 Element slots. Also, set the Target Offsets Elements property size to 37. This will provide you with 37 Element slots. Note that you now have 37 target obstacle game objects in the Scene. Each has its own Offset child game object.

You now need to populate all 37 Element slots with the obstacle game objects in the hierarchy. Note that you should only use the obstacle game objects that are activated, as those that are deactivated haven’t been configured with the necessary components. Twenty-three of these obstacle game objects are available as children of the Environment game object, and you can find the remaining 14 by navigating to Environment ➤ World ➤ Map Objects, see Figures 22-5 and 22-6 earlier in this chapter.

For each obstacle game object you populate the Targets Elements list with, you should also populate the Target Offsets Elements list with the corresponding obstacle Offset child game object. This way, you’ll ensure that you don’t match one obstacle game object with a different Offset obstacle game object. Figure 22-17 shows 18 of the Targets Element list slots populated with obstacle game objects. You’ll need to populate this list with all 37 obstacle game objects.

Figure 22-18 shows 8 Target Offsets Elements list slots populated with the obstacle game objects Offset child game objects. You will need to populate this list with all 37 Offset child game objects.

We now need to set up a Rule that defines which target obstacles will be considered ready to be attached to the Ball. You have assigned a Collision Tracker component to each obstacle game object in the Scene. Whenever the Ball collides with an obstacle, the Collision Started event in the Collision Tracker component for that specific obstacle gets triggered, setting the obstacle’s Tag to Grabbable.

The Rule that you’ll create as part of the Target Validity property of the Mutators Object Follower Obstacles game object will only allow an obstacle game object whose Tag is set to Grabbable to be attached to the Ball when the Ball collides with the obstacle. According to this Rule, when the Ball collides with an obstacle whose Tag is set to Grabbable, it will be attached to the Ball. It will then begin to follow the Ball using the Offset that was created.

Let’s set up this Rule now. In the hierarchy, with the Garden game object selected, create a new empty child game object and rename it “Attach Rule.” Select the Attach Rule game object, and in the Inspector, add two new components to it: the Any Tag Rule component and the String Observable List component . We’ve already used both of these components in Chapter 16, when we set up the Snap Zone Valid Tags rule game object in the Demo scene.

Drag and drop the String Observable List component from the Inspector onto the String Observable List property parameter in the Any Tag Rule component. Set the Attach Rule (String Observable List)’s property size to 1 for the latter component. This will provide you with an Element 0 slot, in which you should type in the value “Grabbable,” see Figure 22-19.

Now that we’ve created the Rule, we need to apply it to the Target Validity property of the Mutators Object Follower Obstacles game object. To do so, select this game object in the hierarchy. Then, locate the Target Validity property in the Inspector. Drag and drop the Attach Rule game object from the hierarchy into this Target Validity property parameter, as shown in Figure 22-20.

The Attach Rule will now only allow any of the 37 listed target obstacle game objects to attach themselves to the Ball. The concerned obstacle Tag is set to Grabbable when the Ball collides with it, and it is then that the obstacle attaches itself to the Ball.

Getting the Ball to Roll About Freely

In this section, we’ll set up the Right Controller Thumbstick to control the Ball’s movement, wherein the player will be allowed to roll the Ball forward, backward, left, and right. The Left Controller Thumbstick is responsible for controlling the player’s movement and rotation.

To achieve realistic Ball movement, we’ll use a physics force against the Ball Rigidbody with the Input Combined Actions Axes to Vector 3 Action prefab . Attempting to achieve such realistic Ball movement without using this VRTK-provided prefab would require us to write math code involving Vectors and Trigonometry. But thanks to this VRTK prefab, we’re not required to write any such math code. Let’s begin setting this up now.

From within the Project tab, expand the “Packages” folder, locate the Tilia Input Combined Actions Unity package, and expand its “Prefabs” folder. Drag and drop the Input Combined Actions Axes to Vector 3 Action prefab into the hierarchy, making it a child of the Garden game object. With the Input Combined Actions Axes to Vector 3 Action game object selected in the hierarchy, ensure that its Axes to Vector 3 Action component has been expanded in the Inspector. Scroll down to the “Axis Settings” section, where you’ll need to set up some properties.

Locate the Lateral Axis property , and drag and drop the Thumbstick Horizontal Axis Right game object into this property parameter. The Lateral Axis (x axis) is responsible for capturing the left and right movement of the Thumbstick. You’ll recall that the Thumbstick Horizontal Axis Right returns a float value between -1 and 1 when you push your Thumbstick either left or right, see Figure 22-21.

Then, do the same for the Longitudinal Axis property , dragging and dropping the Thumbstick Vertical Axis Right game object into its property parameter. The Longitudinal Axis (z axis) captures the forward and backward movement of your Thumbstick. The Thumbstick Vertical Axis Right returns a float value between -1 and 1 when you push your Thumbstick either forward or backward, see Figure 22-21.

As these lateral and longitudinal axes values are too small to have any real impact on the movement and rotation of the Ball, we’ll use the Multiplier property in conjunction with the Time Multiplier property to obtain a vector value that will be applied as the force to the Balls Rigidbody. Set the X and Z values of the Multiplier property to 100. Leave its Y value at 1, as you haven’t specified anything for the Vertical Axis property since you don’t want your Ball moving up and down.

Next, set the Time Multiplier property to Delta Time. This ensures that value of each axis will be computed based on the time elapsed since the last update frame only; otherwise, you would encounter an incredibly fast-moving Ball. The settings for your Dead Zone can be left as is, or you could fine-tune them to your liking, see Figure 22-21.

Last, we need to set up the Value Changed event of the Axis to Vector 3 Action component , which is triggered whenever you move the right Thumbstick around. Expand the Value Changed event, and click the plus symbol located in its bottom right corner to add a new event listener. Then, drag and drop the Ball game object into this event listener box. For this function, select Rigidbody, Add Force from within the “Dynamic Vector 3” section. The Lateral and Longitudinal Axis values, combined with the Multiplier and Time Multiplier, are fed as a Vector 3 to the Value Changed event, which then uses this Vector 3 value to apply force to the Ball Rigidbody, which gets the Ball to move, see Figure 22-22.

Using the Input Combined Actions Axes to Vector 3 Action, we’ve taken axis input data from our Thumbstick and converted it into movement and rotational information that the Ball can use. All the math involved in obtaining this information has been encapsulated into the VRTK’s Axes to Vector 3 Action component.

Now, playtest the scene using your VR headset and roll the Ball around. Note the fluidity of the Ball movement, as physics has been applied to it. Approach one of the obstacles, and roll the Ball onto it. You’ll see that it attaches itself to the Ball. We’re now able to collect obstacles in our game.

Spatial Tooltip to Display Countdown Timer

In this section, we’ll learn to set up a Countdown Timer for our minigame. This timer counts down the seconds you have left to complete the level, and upon the timer reaching zero, you’re no longer able to roll the Ball any further. This Countdown Timer will be displayed in the world using the Visuals Tooltip prefab provided by the VRTK. You could quickly write a Countdown Timer script yourself. The reason for setting up a Countdown Timer here is mainly to learn how to use the Moment Processor available with VRTK. Once you wrap your brain around this setup, you’ll find yourself using the Countdown Timer in several situations. Let’s begin.

First, let’s set up the Visuals Tooltip that will be used to display the Countdown Timer. You already learned how to set this up when you created the Slider and Snap Zone inventory slots.

From within the Projects tab, expand the “Packages” folder and locate the Tilia Visual’s Tooltip Unity package. Expand its “Prefabs” folder, and drag and drop the Visuals Tooltip prefab into the hierarchy, making it a child of the Garden game object. Rename this Visuals Tooltip game object “Visuals Tooltip Timer.”

With this game object selected in the hierarchy, add the Tooltip Text component to it in the Inspector. Then, drag and drop the Tooltip Facade component into the Tool Tip Facade property parameter of the Tooltip Text component . Next, in the Tooltip Facade component, set the Facing Source property to the Headset Alias game object. Leave the Line Origin property empty. Set the Font Size to 50, as shown in Figure 22-23.

Now, with the Visuals Tooltip Timer game object still selected in the hierarchy, create an empty child game object within it and rename this child game object “Offset Tooltip.” Your Tooltip will follow your Play Area Alias, and this Offset Tooltip game object will allow you to offset the Tooltip timer a certain distance forward from the Play Area Alias. Select the Offset Tooltip game object in the hierarchy, and set its Transform Position property values as follows: X = 0; Y = -0.75; and Z = 2. Last, set its Transform Rotation Y value to 180. You can fine-tune these values to your liking if you wish, see Figure 22-24.

Now that our Visuals Tooltip Timer game object has been set up, we need to set up a Mutators Object Follower so that the Visuals Tooltip Timer game object can follow the Play Area Alias around at the given Offset distance. Let’s do this now.

Select the “Packages” folder in the Project tab, and locate the Tilia Mutators Object Follower Unity package and expand it until you reach its “Prefabs” folder. Drag and drop the Mutators Object Follower prefab into the hierarchy, making it a child of the Garden game object. Rename this Mutators Object Follower game object “Mutators Object Follower Tooltip.” With this game object selected in the hierarchy, ensure that its Object Follower component has been expanded in the Inspector. Set its Sources Elements property size to 1. This provides you with an Element 0 slot. Drag and drop the Play Area Alias game object from the hierarchy into this slot. The Play Area Alias is the Source Object that the Visuals Tooltip Timer game object will follow. Now, set the Targets Elements property size to 1. This provides you with an Element 0 slot. Drag and drop the Visuals Tooltip Timer game object into this slot. Next, set the Target Offsets Elements property size to 1. This provides you with an Element 0 slot. Drag and drop the Offset Tooltip game object into this 0 slot.

We have now set up the Visuals Tooltip Timer game object so that it is always positioned in front of us as we move around in the Scene, see Figure 22-25.

Setting Up the Countdown Timer and Moment Processor

The VRTK provides you with a Countdown Timer component that can be used to create a seconds countdown. Once this Countdown Timer reaches zero, you can perform an action. That action is to deactivate the Ball so that the player can no longer roll it farther. First, we’ll set up the Countdown Timer game object and then we’ll set up the two supporting objects needed to get a Moment Processor working. Let’s begin.

In the hierarchy, with the Garden game object selected, create a new empty game object and rename it “Timer.” Within the Inspector, add two new components to this Timer game object: Countdown Timer and Any Action .

With the Countdown Timer component expanded, set the Start Time property to 300 seconds. This allows the player five minutes to collect all obstacles in the level. You can adjust this Start Time property value to your liking, but note that its value should be in seconds.

Then, expand the Completed event, and click the plus symbol located in the bottom right corner to add a new event listener. Drag and drop the Ball game object into this event listener box. For this function, select Game Object, Set Active, and ensure that the check box below is left unchecked. This ensures that once your Countdown Timer has completed (i.e., reached 0), the Ball will be immediately deactivated and you’ll no longer be able to move the Ball any farther, as the time allotted to complete the level will have elapsed.

Next, expand the Remaining Time Emitted event, and click the plus symbol in the bottom right corner to add a new event listener. Drag and drop the Visuals Tooltip Timer game object into this event listener box. For thus function, select Tooltip Text, Show Tooltip from the “Dynamic Float” section, see Figure 22-26.

The Remaining Time Emitted event will be triggered whenever the Countdown Timers, Emit Remaining Time method is invoked. This method passes a float value of the seconds remaining to the Remaining Time Emitted event, which in turn passes this value to the Show Tooltip method, displaying the seconds remaining on the Tooltip. The Countdown Timers, Emit Remaining Time method will be invoked via the Moment Processor, which we’ll set up shortly.

To get the Countdown Timer mechanism working, you first need to tell the Timer to begin counting down. You’ll start the Countdown Timer by calling its Begin method via the Any Action component’s Activated event. This component can be used to execute any possible action. Here, you’ll utilize it to execute the Countdown Timer’s Begin action.

For the Timer game object, ensure that the Any Action component has been expanded in the Inspector. To get the Countdown Timer to start counting down, expand the Activated event in the Any Action component and click the plus symbol in the bottom right corner to add a new event listener. Drag and drop the Timer game object from the hierarchy into this event listener box. For this function, select Countdown Timer, Begin from the “Static Parameters” section, see Figure 22-27.

Now, the moment the Any Action component’s Initial Value property is true, the Activated event in it will be triggered and the entire countdown mechanism will roll into motion. You need to ensure that this component is in a true state when the game starts so that the countdown mechanism can start rolling. Check the box for the Initial Value property in the Any Action component to set it to true, as shown in Figure 22-27.

Now that we’ve made the Countdown Timer functional, it needs to be polled repeatedly at a fixed interval—say, every half a second—so that at this given interval, the time remaining can be displayed via the Visuals Tooltip Timer game object. If you were writing your script, you could easily achieve this using Unity’s Update method. However, the VRTK provides you with a Moment Processor that functions like Unity’s Update method and can be used to call another Process repeatedly whenever a specific time interval has elapsed. We’ll use the Moment Processor to call the Countdown Timer Process after every half a second has elapsed. Let’s set up the Moment Processor game object first.

In the hierarchy, with the Garden game object selected, create a new empty game object and rename it “Moment Processor.” Add two new components to the Moment Processor game object in the Inspector: the Moment Processor and the Moment Process Observable List. In the Moment Processor component, set the value for the Process Moment property to Update. This ensures that the processes you invoke, like processing a code block in Unity’s Update method, will be done in Update. Now, drag and drop the Moment Process Observable List component into the None (Moment Processes Observable list) text box in the Moment Processor component, as shown in Figure 22-28.

In the Moment Processor component, set the Moment Processor, Elements property size to 1, which will provide you with an Element 0 slot. Drop a Moment Process that will be processed every Update into this slot, see Figure 22-29.

Let’s now set up a Moment Process that can be processed on every Update. In the hierarchy, with the Garden game object selected, create a new empty game object and rename it “Process Every Half Second.” With this game object selected in the hierarchy in the Inspector, add two new components: the Moment Process and the Event Process.

Drag and drop the Process Every Half Second game object from the hierarchy into the Source property of the Moment Process component. You’ll be prompted to choose between a Moment Process and an Event Process. Select Event Process, as it is an event that you will execute as part of the Moment Process, see Figure 22-30.

Set the value of the Interval property to 0.5, as shown in Figure 22-31, so that the Event Process you’ll set up will be called only every half a second, not every time an Update runs. In the Event Process component of the Process Every Half Second game object, expand the Event drop-down and click the plus symbol in the bottom right corner to add a new event listener. Drag and drop the Timer game object from the hierarchy into this event listener box. For the function, select Countdown Timer, Emit Remaining Time, as shown in the figure. Here, setting the Interval to 0.5 means that it will call the Countdown Timer Emit Remaining Time method every half a second.

Last, select the Moment Processor game object in the hierarchy. In its Moment Processor component, locate Moment Process Observable List, Elements, Element 0 slot. Drag and drop the Process Every Half Second game object from the hierarchy into this slot.

We have now provided the Moment Processor with a Moment Process that will be executed during an Update process, and we’ve set up the Moment Processor so that the Countdown Timer is fully functional, see Figure 22-32.

If you found setting up all these connections to be a mind bender, let me summarize how all the connections you hooked up and synced together got the Countdown Timer to work. Let’s start with the Moment Processor that runs processes assigned to it, every Update. Every Update, the Moment Processor will run the only Moment Process you have assigned—Process Every Half Second, see Figure 22-32.

The Process Every Half Second (Moment Process), shown in Figure 22-32, suggests that when it’s invoked, a half a second must have elapsed before it triggers the Event Process component’s Event () event . At that point, it will execute the Countdown Timer, Emit Remaining Time metho

The moment the Countdown Timer, Emit Remaining Time method is invoked, the Timer game objects, Remaining Time Emitted event will be triggered. The triggering of this event results in the Visuals Tooltip Timer game object displaying the floating-point value —or the time in seconds remaining as per the Countdown Timer—getting passed to it. Look back at Figure 22-26.

Figure 22-33 shows an image summarizing the entire Countdown Timer process workflow. Before playtesting the minigame, ensure that the Oculus-provided Custom Hand Right and Custom Hand Left are deactivated, and that the Hand Proto Right and Hand Proto Left are activated. Then, playtest your minigame using your VR headset. Use the Left Controller to move within the game world and the Right Controller to roll the Ball onto the obstacle game objects strewn around the garden path. Note how they attach themselves to the Ball when it collides with them. See how many obstacles you can gather in the five minutes of game play allotted, and, if required, increase the Countdown Timer component’s Start Time property value.

Enhancing the Minigame

Summary

In the final chapter of this book, we have created a minigame without writing a single line of code, using several mechanics we learned about throughout the book. We learned how to create a Countdown Timer and set up a Moment Processor. We also learned to use a critical VRTK prefab, Input Combined Actions Axes to Vector 3 Action, to roll the Ball around by adding force to its Rigidbody, thereby avoiding the need to write math code involving Vectors and Trigonometry. We used the Collision Tracker component to set up Source, Targets, and Target Offset game objects that allowed obstacle game objects to attach themselves to the Ball. We set up a Spatial Tooltip to display the game’s Countdown Timer. We utilized the VRTK-provided Countdown Timer to count down time in seconds, ensuring that once the timer reaches zero, the game ends and the player isn’t allowed to move the Ball any farther. You learned to set up the Input Combined Actions Axes to Vector 3 Action prefab to allow the player to move the Ball realistically around the garden path. You also learned about the Countdown Timer’s Completed and Remaining Time Emitted events. In the last section of the chapter, we set up a Moment Processor and used its Update process moment to call another Process repeatedly whenever a specific time interval has elapsed. Along the way, we became familiar with how to use the Moment Process and Event Process components. We wrapped up the chapter by testing our minigame using our VR headset and, finally, were provided some tips on enhancing this minigame by adding some simple mechanics.