masked wall and transparency glitch returned

Mark

#1 Posted 21 April 2022 - 09:01 AM

Some of you that have been modding for a long time may remember when this was a problem and it was fixed shortly after discovery.

When a masked wall has transparency you can see a line along the top edge as in my pic. I'm assuming the old bug has returned where the bottom line of the masked wall is offset and gets displayed at the top. This is in Polymost but it happens in Polymer too. This is using the latest revision but was also showing using a revision from last year. The line didn't show in Mapster.

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This post has been edited by Mark: 21 April 2022 - 09:12 AM

Mark

#2 Posted 21 April 2022 - 09:06 AM

oops, double post

This post has been edited by Mark: 21 April 2022 - 09:06 AM

Mark

#3 Posted 28 November 2022 - 08:18 AM

It took dozens of revision bisects to track this issue down the last time it happened and got fixed. Way back in May of 2010. Revision 1623 had the lines on top, the next public revision 1632 did not. So somewhere in between those 2 fixed the issue last time and may be a clue to fixing it this time around. I just checked, latest eduke32 still has the issue.

Mark

#4 Posted 13 February 2023 - 07:52 AM

Its been more than 2 months and no response so I'm posting again. Testing this morning shows it is acting like the previous problem from years ago where the bottom row of pixels has been shifted to the top. I tested by making the bottom pixels of the texture transparent. The black lines on top went away.

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Striker

Auramancer

#5 Posted 13 February 2023 - 12:42 PM

This is due to how texel colors mix with their neighbours with bi-linear filtering enabled, thus some of the color at the bottom of the texture mixes with the alpha at the top of the image, crossing the boundary where the texture wraps. Hopefully fixable by enabling clamping. (Might need to be done in-engine, but you might be able to force it in your GPU settings)