Discrepancy in UMG between PC & HTML5


My plugin doesn’t work correctly on HTML5, but it does on PC. I had an impression that Unreal Engine 4
deploys are consistent across platforms provided one doesn’t use platform dependent external libraries,
which is one of the main selling points for many modern engines. In this case I indeed used none, just the vanilla UE4 stuff.

HTML5 problem:

PC no problem:

One can clearly see that the map texture in the HTML5 version is mirrored on the y-axis in relation to the correct PC version & of course the material placement for the actor representations is all out of whack. The only thing that’s consistent is the arrows, but they are rendered as UCanvasPanel slots (because they sometimes need to go outside of the widget bounds for aesthetic reasons), whilst others are drawn on UCanvasRenderTarget2D.

Hello ,

I have a few questions for you that will help narrow down what issue it is that you are experiencing.

Quick questions:

  1. Can you reproduce this issue in a clean project?
  2. If so, could you provide a detailed list of steps to reproduce this issue on our end?
  3. Could you provide screen shots of any blueprints/widgets/settings that may be involved with this issue?

Hi Rudy,

The thing is: it’s about a plugin that we made at Heavy Wizards, a plugin that had recently been sent for the Marketplace submission. The plugin is called “Heavy Wizards Radar”.

What’s baffling to me is that I’m not using any external libs, nor any platform specific UE4 code (I’ve never used such code once & not even sure if such code is exposed to the clients at all).

So in short you would need to have an access to our plugin in order to try & resolve this issue. The code since had been sent to your colleagues at the Marketplace Submission. It’s probably best if you contact them & request the source. We have sent the plugin together with a 3rd person sample project that has everything set up already.

The submission numbers are as follows (there are 2 for some reason): 42475 & 122196

I ran a couple of tests with the information that you have provided. However, I was unable to reproduce this issue on our end. Could you answer the questions from my previous post? Can you reproduce this issue without using the plugin that you have created?

Well, the problem is definitely with UCanvasRenderTarget2D because even without the whole plugin hullabaloo it leaves us with the mirrored texture (it’s packed in a material & then drawn with K2_DrawMaterial), I guess I could try making a simple UImage widget & setting its brush to a custom UCanvasRenderTarget2D. What do you think?

I tried running a very stripped down Blueprint version of our plugin, but cannot reproduce this issue. It might be the DPI because the plugin does a lot of calculations involving pixels. The DPI doesn’t explain the mirroring though, only the materials drawn in the wrong locations. I’ll need to dig deeper.

I’ve played with various DPI settings in the editor & everything works as it should. I really thought it was something I did. I’m going to try & test this on Android.

When you are finished running your tests, could you update the thread with any information you find that may be relevant to the issue? Could you also provide the clean project used to reproduce this issue on your end so that I could take a closer look?

The main problem with this is that my (C++) plugin is of a moderate complexity. There’s just so much that can go wrong. In your opinion: is it me or is it the engine that’s at fault here? As I said I’m not using any platform specific stuff, so in theory it should work consistently across all platforms… in theory.

I’ll try to tinker something together tomorrow so that you could take a look for yourself, but I’d need to strip everything down bare bone. Let’s hope I can reproduce the issue with this simplified version of my plugin in the way I couldn’t with the extremely simple BP version.

I’ve stripped down my plugin to the bone, the only thing it does now is drawing one texture on a UCanvasRenderTarget2D. Luckily I could reproduce the issue this way. I’m providing you a link to a .7z file containing the project from our Dropbox. Don’t forget to regenerate it, because I deleted everything that wasn’t essential, to reduce size.

EDIT: I was focused on the flipped texture issue in HTML5 as opposed to PIE & PC. That’s the exact issue I could reproduce. We’ll worry about other issues later.

Hello ,

After taking a look at the project provided I was able to reproduce this issue on our end. I have written up a report and I have submitted it to the developers for further consideration. I have also provided a link to the public tracker. Please feel free to use the link provided for future updates.

Link: Unreal Engine Issues and Bug Tracker (UE-40051)

Make it a great day

Thank you, Rudy! Needless to say, this bug really bugs me. :slight_smile: