Material do not render when texture sample add up over 3 in mobile preview

In material editor, I got 6 texture samples(each one is actully made up with 3 nodes: a “texture sample” “multiplied” by an “material instance parameter”) and I added them together then plug into emissive channel. It works fine when I play in viewport and package to windows. But when I play in mobile preview, this texutre would not render. Then I found if I only add 3 or less texture samples and plug then into emissive channel, it will work properly, no matter which 3 I pluged in. But once I added a sample number 4, the whole material would not render in mobile preview mode (even the base color channel would not render as well.

Hey Porcelania -

There is a hardware limit on Mobile devices of 5 Texture Samples in your materials, reference here. I am a bit confused by your description though, would it be possible to upload a screenshot of your material, so I can look into reproducing this issue?

Thank You

Eric Ketchum

here is 6 groups of nodes, each contains a “texture sample” node, a “collection param” node and a “Multiply” node. I added all them together and pluged into emmissive channel. Each group cotains a road on map, when I click relevant button, the road would be highlighted.

Hey Porecelania -

In the material you are using you have 7 different texture samples which will not render in a mobile device. It looks like you should be taking advantage of greypacking your textures so that you are only loading 1 texture but are getting 4 different black and white images for the same amount of memory as 1 full color texture sample. And for what it looks like you are doing this would be an ideal solution. Here is a sample material setup using a greypacked texture, it is set up to show both using a single UV layout and a switch to show the same 1 texture being used with multiple different UV inputs:

And here is what it looks like (I have a Material Instant with the switch adjusted to show both setups in the material):

This should solve your issue with rendering the material on mobile devices.

Let me know if I can explain or if you are still experiencing problems -

Eric Ketchum

Also just for reference, here is a PNG example of greypacking without an alpha channel like the TGA I used in the above example, but it is a good example of a texture that has been greypacked.