Unity Without OpenGL ES 2.0 Is All Pink on Fire TV Stick

I dug up my disassembled Fire TV Stick (second generation) and it is now back up and running again. This was an entertaining diversion in its own right, but during the update and Android Studio onboarding process, I kept thinking: why might I want to do this beyond “to see if I could”? This was the same question I asked myself when I investigated the Roku Independent Developer’s Kit just before taking apart some Roku devices. For a home tinkerer, what advantage did they have over a roughly comparable Raspberry Pi Zero? I didn’t have a good answer for Roku, but I have a good answer for Fire TV: because it is an Android device, and Android is a target platform for Unity. Raspberry Pi and Roku IDK, in comparison, are not.

I don’t know if this will be useful for me personally, but at the very least I could try installing my existing Unity project Bouncy Bouncy Lights on the device. Loading up Unity Hub, I saw that Unity had recently released 2021 LTS so I thought I might as well upgrade my project before installing Unity Android target platform tools. Since Bouncy Bouncy Lights was a very simple Unity project, there were no problems upgrading. Then I could build my *.apk file which I could install on my Fire TV just like introductory Android Studio projects. There were no error messages upon installation, but upon launch I got a warning: “Your device does not match the hardware requirements of this application.” What’s the requirement? I didn’t know yet, but I got a hint when I chose to continue anyway: everything on screen rendered a uniform shade of pink.

Going online for answers, I found many different problems and solutions for Unity rendering all pink. I understand pink-ness is a symptom of something going wrong in the Unity graphics rendering pipeline, and it is a symptom that can have many different causes. Without a single solution, further experiment and diagnosis is required.

Most of the problems (and solutions) are in the Unity “Edit”/”Project Settings…”/”Player”/”Other Settings” menu. This Unity forum thread with the same “hardware requirements” error message suggests checking to ensure “Auto Graphics API” is checked (it was) and “Rendering Path” to Linear (no effect). This person’s blog post was also dealing with a Fire TV and their solution was checking “Auto Graphics API” which I am already doing. But what if I uncheck that box? What does this menu option do (or not do?)

Unchecking that box unveils a list of two Graphics APIs: Vulkan and OpenGLES3. Hmm, I think I see the problem here. Fire TV Stick second generation hardware specification page says it only supported OpenGL ES 2.0. Digging further into Unity documentation found that OpenGL ES 2.0 support is deprecated and not included by default, but we could add it to a project if we need it. Clicking the plus sign allowed us to add it as a graphics API for use in our Unity app:

Once OpenGL ES 2.0 is included in the project as a fallback graphics API, I could rebuild the *.apk file and install the updated version.

I got colors back! It is no longer all pink, and cubes that are pink look like they’re supposed to be pink. So the cubes look fine, but all color has disappeared from the platform. It was supposed to have splotches of color cast by randomly colored lights attached to each block.

Instead of showing different colors, it has apparently averaged to a uniform gray. I guess this is where an older graphics API gets tripped up and why we want newer APIs for best results. But at least it is better than a screen full of pink, even if the solution in my case was to uncheck “Auto Graphics API”. The opposite of what other people have said online! Ah well.

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