On mobile, all of my MaterialBillboardComponents that are using a translucent material disappear when I look up, but reappear when I look down. If I make the material opaque, the issue doesn’t occur.
This has only cropped up very recently, since upgrading to either 4.8.2 or 4.8.3.
There’s nothing special about the material itself; it’s just a texture sample with RGB plugged into Emissive, alpha plugged into Opacity, and blend mode set to Translucent and Unlit. The texture itself is irrelevant; the same thing happens when I use a flat colour.
This is a known issue with Material Billboard and the fix for this issue is currently in testing, while I am not certain when it will make it through the testing process, it will be coming, for reference UE-4725
I don’t know about mobile but how I’ve been doing clouds is actually switching it to additive and going through the emissive with a mask and color control for my nebulas. I don’t get the flickering when I do that.
Yeah I wouldn’t know on mobile, ours is on PC but I do know I did have that flickering issue until I stopped using the opacity channel and just masked it out through the emissive
When you say on mobile, can you be as specific as possible? Is it Mobile Preview, Android or iOS, and which device or devices are you experiencing this issue on specifically.
This happens both on Mobile Preview and the Android device I’m testing on, which is a Galaxy Tab 10.1. I don’t have the device on me at the moment, so I can’t privide much more detailed specs at this stage. When I get back on Monday I’ll check it on some other devices as well.
I have been running some tests to see if I can replicate your issue and have been unsuccessful as of yet. I have attached a simple blank reproduction project below. Can you please take a moment and look at the setup I am using and if your setup is different, please adjust the project and upload back here.
Thanks for providing the test project. I’ll get to it as soon as possible. The only thing I can think of off the top of my head that might be different is that my camera view is controlled via a Camera component attached to my Pawn blueprint with bUsePawnControlRotation=true.
I found the issue. Some objects in my map were using the M_Glass material from StarterContent, which has a Feature Level Switch on Refraction that somehow kills all transparency altogether when looking in certain directions, even on completely unrelated materials.
I’ve modified [the project you sent me][2] to include a single mesh with the glass material applied. When playing in Mobile Preview, all transparent elements disappear as I experienced in my other project.
Thank you for your test project it clearly should the issue. I was able to test it in a variety of engine versions and it looks as this issue has been addressed and corrected by 4.9 Preview 4 which means the official release of 4.9 will correct this issue.
