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Capture Reflection Issues on Mobile

Development Discussion Rendering
#1

So, I’m trying to get the sky to reflect on objects in Mobile, but in the previewer it seems Sphere Reflection Captures do not include the skybox at all, and the Skylight does not provide reflections on mobile, leaving my metallic materials showing up as black. The only method I found to get a proper sky reflection to work was to render a skybox from a capture object under the Shader Model 5 previewer, convert to a static texture, then apply that texture to the Sphere Reflection Capture actors and switch them to use the cubemap.

Of course, if the Reflection Captures just captured the scene properly, metallic objects wouldn’t show up as black. Is this a bug with the captures, or is this something I can fix on my end?

#2

Do you have static skylight? We use static skylight and sphere reflections show the sky just fine on mobile. Remember that atmospheric fog isn’t supported on mobile. Also mobile uses pre captured reflection captures instead of capturing them at mobile. So reflections are captured using SM5 rendered not the mobile one.

#3

That seems strange if you place a Spherical Reflection Capture in the engine you need to update it in Shader Model 5, then switch back to mobile rendering in order for it to work. I would imagine the engine would be able to take care of such issues behind the scenes. I also noticed this issue attempting to make a cubemap from a scene capture cube actor: in the mobile previewer, it just doesn’t work. That could possibly be the issue.

Typically I use a stationary skylight for PC builds. I’ll switch it to static, build, and see what I get.

#4

Unfortunately, this issue is persistent. Sphere capture reflection actors do NOT include the skybox. They only provide local reflections. So if you’re making a character that is largely based on metal materials, the reflection (and thus the resulting metallic material) will mainly show up as black.

#5

Found the issue: you can’t update reflection captures in the mobile previewer (I was using ES2). You need to switch back to Shader Model 5 (the PC view) when building lighting and updating reflections or else they won’t work properly.

#6

Is sad they still did not fix it un UE4.19.2

#7

I guess you’ll just have to develop in SM5 and switch down to the mobile previewer from time to time. I don’t think this is something that can be fixed: the engine literally switches to a new API in order to show you what the project will look like. Mobile APIs have limitations that SM5 does not, so the best engine experience will always be in SM5.