Much more Landscape Texture Samples on Mac

I’m using a Landscape Material with many Layers. All are optimized with a Landscape Layer Switch. On Windows all is fine but on Mac the most Landscape Sections does not compile in the same Level:

Failed to compile Material <MaterialName> for platform GLSL_150_MAC, Default Material will be used in game.

In the Instance I’ve seen that there are to much Texture Samplers. Then I deactivated all Normal Maps (8 Texture Samplers). My Material has now 13/16 Texture Samplers with all Layers active but there are still 2 Sections that doesn’t compile. How is this possible? Why does the Windows Version has no errors with 8 Texture Samplers more?

Edit:
UE 4.8.2 Launcher Version

When I preview Shader Model 4 on Windows all is fine.

Hi user37337 -

Thank you for your report. We have assigned this issue to a member of our support staff, and they will begin investigation as soon as possible. If we are unable to reproduce the issue, or we need additional information, our staff member will comment here with additional questions. Otherwise, we will post an ‘Answer’ once we have logged the issue in our bug database or we have a solution for it.

In the meantime, please be sure to review our suggestions for how to report a bug, and feel free to edit your post if you have additional information to provide:

Thank you -

Eric Ketchum

Hey user37337,

We added a new feature in 4.6 which allows you to ‘share’ your texture samples. This increases the texture sample ceiling to 128 texture samples per material shader!

Materials with Many Textures

You can find the full release notes below.

Cheers,

Hi,
thank you for the answer but this is not a resolution for me. I haven’t used this feature with DirectX with intent to be compatible with Mac but it doesn’t compile at Mac anyway.

I found a helpful forum post that will help explain why you are limited the number of texture samples on your Mac. In short, it is a limitation that we were able to work around recently by using the Shared: Wrapped texture setting.

Max Texture Samples

Basically you are limited by the shader model that Mac’s use at the moment.

Cheers,