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Adding sound cues to gaze navigation

I want sound to play a big role in my environment, so I set out to make it so when you gaze at the spheres to teleport to that location, it also plays a sound cue. I downloaded several royalty-free sound effects and music from and including some deep bell and gong sounds.

I then imported them as .wav files into Unreal. You have to convert them to a Cue, by simplying right-clicking and choose “Create cue.”

Then you select the trigger capsule you wish to play the sound, and right-click, choose “Add Event / OnActorBeginOverlap”.

Sound cues
Sound cues

At this point, Unreal switches you to the Level Blueprint, where you can begin to work with the Event. Pull out a wire to Play Sound at Location, then near the Sound input, select the sound cue you want to play from the pull-down menu. It’s that simple!


Packaging issues

To package a project for Windows from Unreal, you must have the proper software installed, including Visual Studio 2015. (See the documentation here.)

I wanted to package my game to send to others, but when I tried File/Package Project/Windows, it packed for a while then gave me a fatal error. Several forum posts I read said to delete your Saved and Intermediate file. This created a tremendous problem when I realized I had started building my introductory level using the Default level, which got deleted when I threw away those folders! Recovering them from the trash only recovered a portion of the scene, so I had to rebuild much of it. Lesson learned: Don’t build your levels in the Default level! Start a new one.

Another thing I did to simply the Package process was to turn off all supported platforms that I wouldn’t be using, such as Linnux and iOS.

By reading through the lines and lines of text in the Error log, I found this:

UATHelper: Packaging (Windows (64-bit)): Cook: LogTexture: Warning: Cannot retrieve source data for mip 0 of texture Mushroom3-texture

This could mean the image file was corrupt. I deleted the Mushroom mesh and texture altogether from my content file, and then my game packaged successfully! Next steps will be to re-save the files, re-import and try again to see if I can use the mushroom mesh.

After the game packaged successfully, the next step was to test the .exe file in VR. When I launched the game, it loaded, but only showed up on the computer monitor, not in the VR headset. After more digging through forums, I found some advice on Blueprints, so I added a Delay of 2 seconds, then something to Enable HMD, and also added the Execute Console Command (although that last part doesn’t seem to work automatically like it should):

Start in VR Blueprint

If your game doesn’t start in VR automatically, you can type the Tilde key on your keyboard while in game, which opens up a command console, then type “stereo on”. This will launch it in the headset.

The thing that seemed to work best though is a very small setting that is hard to miss and not very well documented. In the Project settings under Description, look for a checkbox that says “Start in VR” under Settings towards the bottom.

Start in VR setting

After doing all this, my game launched in VR successfully.

Animating the salamander – issues with spline

I found a great tutorial from Hangry Bunnies From Mars on how to get an animated mesh to move along a spline. I created the blueprints and everything worked great, except for one problem – the salamander moves sideways to the spline. You can see in the image below, the salamander is 90 degrees rotated from the vector of the spline, which causes him to walk sideways, looking very silly.

I tried rotating the mesh in the blueprint viewport, but no luck. The rotation may look fine in the viewport, but when you play the animation, it reverts back to it’s original orientation.

This looks correct, but orientation doesn’t stay

One thing that’s very nice and handy about Unreal blueprints, is that in the Details panel where you plug in the Animation and Mesh they are color coded green and megenta so you know which part of the mesh to plug in where. Pretty handy once I noticed it!

Below is the Event Graph blueprint. Everything works splendidly, except the proper orientation.

After spending quite a bit of time on this without an answer, I went to Plan B, which was to animate it using Cinematics.

Salamander Cinematic

This method worked beautifully, and kept the proper scaling and rotation.

There are a lot of tutorials out there on how to attach an animated mesh to a spline using Blueprints, which leads me to wonder why that method might be preferred over using a Cinematic?


Introduction Tutorial Level

I decided it would be helpful to have a “pre-level” in my game that would introduce new players to the concept of Gaze Teleportation, so they know how to move around the scene.

I imported some assets I had created last semester, and set up a stage of sorts.

I also learned how to create Billboards, which are incredibly useful floating text boxes that always face the player.

Intro Level
Intro Level

I also wanted to make the spheres representing the chakras light up one by one, to simulate what will happen metaphorically in the game. I found a great, easy to follow tutorial by Brigid Costello that was so valuable to learning this quickly.

Chakra lights
Chakra lights

To do this, I created a Cinematic. I assigned each sphere to a new “Empty Actor Group” then gave each group a Visibility track. You can keyframe when things are Visible (Show) or Invisible (Hide). I timed it so they each become visible a second after the previous one, so they light up in sequence.

I then created a small Cone shape in the scene, and assigned a Movement track to it. I keyframed it so it flies backwards away from the figure towards the teleportation sphere, thus drawing the viewers’ attention. Once the viewer gazes at that sphere, they are instantly teleported to that spot.

Directional cone
Directional cone

Overall this was a good lesson for me in Cinematics and Billboards.


User testing

Recently I began user testing on my prototype. I have been able to sample a variety of ages and levels of VR experience. A few things have surfaced repeatedly:

  • “Climbing the tree” (moving upwards via gaze teleportation to each sphere up and around the tree root) causes more than half the people to experience a feeling of vertigo and anxiety about heights. Users literally feel like they could fall.
    • To address this I plan to insert visual “platforms” in the shape of tree fungus that allows users to feel they are standing on something as they teleport
  • Some people prefer to stand, while three people age 60+ who also experience balance problems in real life prefer to sit
    • I will revise the Protocol research document to indicate that people will be asked if they prefer to sit or stand
  • Switching to the Oculus platform means that during development I need to be mindful there is now a cord coming from the headset, which could cause issues if users are expected to continuously turn around (spiral pattern moving upwards)
  • Almost everyone responded positively to the music used in the scene.
    • I plan to add additional musical elements, like bells or chimes as users interact with the scene
  • Most people seemed confused by the method of gaze navigation; it had to be verbally explained to them
    • I plan to add an introductory level that demonstrates gaze navigation, and also add animated assets that guide the user by drawing their gaze to the appropriate area
  • Not everyone is comfortable enough with VR to even want to try it. People who are uncomfortable with “video games” or those who have motion sickness concerns will most likely choose not to participate.

Teleportation navigation

This week I continued to develop the gaze navigation system. I created an Emissive (glowing) material for each of the seven spheres and place them in an upwards spiral pattern around the tree root. Near the base of the roots you can see the VR Pawn Actor which has a long “cursor” attached. When the player moves their head and the cursor encounters one of the spheres, the player teleports to that location.

I updated the tree to a more realistic looking bark texture, and tweaked some of the lighting settings from last time. I also added the mushrooms.

After tweaking the lighting, I used the Build Lighting feature, and received the error that I needed to set a “Lightmass Importance Volume,” which I did after looking up a brief tutorial. As you can see below, there are thousands of light calculations going on, which tends to slow down your game frame rate.

By placing a Lightmass Importance Volume, you can control where Unreal Engine puts most of its energy when calculating static lights, which improves performance. Below you can see much fewer instances of calculations.

Documentation for developing for Oculus, Gear VR and plugins for Unreal Engine

Unreal Engine has a section in their Gear VR documentation on how to build cameras, set up functions for Gear VR touchpad, and the motion controller. While these are helpful, it would be great if there was more support for Gear VR built into Unreal instead of developers having to custom-build things. Also, be aware that sometimes Unreal’s documentation is not up to date, and you may need to cross-reference against Oculus’s Developer documentation as well.

Note: if you are developing for Oculus, especially for Gear VR, there are certain plugins that need to be turned on in order to get the Blueprints you need.

Oculus has a section in their documentation on Blueprints, and how to turn on the plugin. So far the documentation is a bit vague and sketchy, but I hope to continue deciphering it.

The Input Blueprint provides a control interface for Touch, Oculus remote, and the Gear VR Controller….Gear VR Controller clickpad events are reported in the Input Blueprint as thumbstick events.

What would be really helpful, would be an Input option to use the Gear VR touchpad or motion controller built into the Inputs/action mapping. So far that does not seem to be an option. If you can use the Action and Axis bindings in the Input section, it works across the entire game and all levels, instead of having to custom build a blueprint each time.


With over 5 million Gear VR headsets sold world-wide, further support within Unreal Engine is a real need for the developer community.

Blueprints for gaze teleportation

In this section, we added to our Blueprint, replacing the PrintScreen value with a function that allows us to move the VR_Pawn (player point of view) to the trigger capsule location when the VR_Pawn pointer overlaps the trigger capsule. In other words, when you look at something, you instantly teleport to it. Below is a pic of the player standing on top of the cauldron after gazing at it.

Teleport to cauldron

Below is an extreme close-up on the salamander – once the player gazed at it, the player was teleported directly to the trigger capsule surrounding the salamander.

Obviously the placement of the capsules need to be fine-tuned so the player doesn’t land so closely upon the object, but the basic interactions are now functional.

Here is the Blueprint that creates this action. Notice the Get Actor Location and Set Actor Location functions.

Blueprints for trigger actions

In this part of the Pluralsight tutorial “Making a VR Experience in Unreal Engine” we get into setting up a trigger capsule for our objects, then using Blueprints to create a PrintString when our gaze encounters the capsule surrounding the object.

Trigger Capsules
Trigger Capsules surrounding objects

We went into the Blueprint for the VR_Pawn and clicked on the Viewport tab at the top of the Blueprint to see the actual object in order to create a very long Cube that was parented to the camera. This allows us to touch or “Overlap” objects in the scene when the camera points at them.

VR Pawn Gaze
VR Pawn Gaze
Gaze misses trigger capsule
Gaze misses trigger capsule

When the gaze/pointer encounters the object, the PrintString prints the word “Hit” instead of “Miss”.

Next, we built the Blueprints to make the program print different words on the screen depending on which object it overlaps.

blueprint print screen
blueprint print screen

WAIT – there is a problem. When the gaze encounters the trigger, it prints the wrong description.

This is not the salamander!

I literally had my wires crossed. I corrected the PrintString outputs.

Corrected Blueprint
Corrected Blueprint

Now the Cauldron string is connected to the Cauldron trigger, same for salamander.

We have successfully demonstrated creating an event (PrintString) when the VR_Pawn camera pointer overlaps a Trigger Capsule.