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A friend has been working on a project, and they have run into issues with using Linear Interpolation & Cubic Interpolation with their complex node tree. This node tree will be working with low resolution textures for a game, these really can't afford to be enlarged just for the purpose of avoiding these visual issues in Blender.

Linear Issue: Repeating does not work seamlessly, every texture tile has a harsh aliased edge around the border of the texture, no Blend mode or known setting fixes this, it is only present in Linear and occurs no matter if it is Opaque or uses Alpha.

enter image description here

Cubic (& Smartest) Issue: Clamping the texture does not work for 1 pixel wide gaps in Alpha, as cubic seems to go beyond a single pixel gap of Alpha. The result is not ideal. TO CLARIFY: The problem is not the white border around the texture, that is a simple fix. The problem is that with Cubic/Smart the near outermost pixels are stretched when this Clamp mode is used.

enter image description here

If anyone has any ideas about solving this, do tell! In the mean time, we use Closest, which is generally not accurate to how the game will handle these low resolution images. .blend (old) contains the node tree, the math that results in these issues is within the "Get UV" group. Interpolation can be adjusted at the Texture 0 Node.

Update: Simpler .blend nodes with option to Clamp outside of the groups.

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  • $\begingroup$ What a branch do you use? Some of nodes (in your linked blend file) are "Undefined" (red) in 2.80 and 2.82 alpha. Some issue can come from combinations, since current node tree is mixing images with Closest and Linear interpolation. $\endgroup$ – vklidu Nov 30 '19 at 21:39
  • $\begingroup$ There is no issue with the current combinations. Technically only one texture is in use and matching them makes no difference. Closest is already the default as I said, this works but it is not accurate to the settings we have available, some form of working interpolation would be great and Linear is the most accurate. The undefined nodes are not a part of the problem, those are normally named by the add-on, the issue in question occurs in the "Get UV" node group. $\endgroup$ – InTheBeef Nov 30 '19 at 21:44
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    $\begingroup$ To attract more people you could simplified blend into node tree that are you focused (if I understood you right the node tree could be like in my WIP answer, right?) $\endgroup$ – vklidu Nov 30 '19 at 23:05
  • $\begingroup$ Done, there's still a lot of complexity though, the issue stems from the node tree afaik. $\endgroup$ – InTheBeef Dec 1 '19 at 3:24
  • $\begingroup$ The test image doesn't seem to be packed in the .blend? Or am I missing something? $\endgroup$ – Robin Betts Dec 1 '19 at 7:39

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