White line on textures

Development Programming & Scripting
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1

I made a tileable forest material and put it on a plane to use as a background but it appears with this sporadic white line on the top.

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I thought it was an issue with the image itself, but I checked and there are no white lines there on the original, even after arbitrarily erasing the top edge to get rid of anything I couldn’t see with the naked eye. I also pasted it into other programs like powerpoint to check if the line still appeared, but still nothing. Consequently, I’m left believing this is an issue with Unreal.

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This is the blueprint for the material and I’m not sure what I’m really doing wrong. Any help would be appreciated.

2

Have you checked the alpha channel in your texture asset to make sure it is not larger than the part you actually want to see?

3

Sorry, I’m not entirely sure what that means (I’m not incredibly experienced with Unreal in general)? The min and max values for the alpha in the texture are just 0 and 1. Toggling the alpha button at the top just fills the background as white too.

4

If you use photoshop for example, and select background with magic wand, it cuts background but it does anti aliasing on edges. So those white lines are from that wrongly marked edge in whatever photo editing tool you made alpha.

You can adjust that edge in unreal material. Use POWER node clamp and multiply to move that edge disappear. However there will always be subtle edge unless you fix alpha in photoshop (or whatever you use).

To check what is in chanels:

  • make two nodes for 4 vector (press 4, it will popup menu, then turn created 4 vector it into parameter)
  • make linear interpolate node (lerp)
  • interpolate from one 4 vector param to another (Set different colors),
  • as driving alpha use alpha frrom texture (but also connect R , G , B separately ans see (check) what is there