Why Is This Happening?

[Ghost_Ellis]

Seems to be a line up this wall, that is textured, but when moving, the thing shown below happens, it flickers in and out of reality, There's also a lot of white pixels to the right of the bug. Not sure why.

The spaces between the walls are incredibly small (under 12px) so maybe that's why? 

Or maybe there's too many 3d floors?

[Kappes Buur]

For those who have no clairvoyant abilities you could provide a link to the map to take a look at.

 

I'm guessing that it could be a slime trail which usually is fixed by rearranging some close-by vertices,

on the other hand it could be something totally different.

Edited June 5 by Kappes Buur

[shroomzy5000]

Would need to see the map in editor to reach a conclusion but since it only happens while moving, this immediately makes me think of walking around a map without textures.  When there is a missing texture, what i understand is what you see is based on your view angle of the linedef.  I would use the MAM (F4), check only the box for "check missing textures".  Backpacking of Kappes statement, i have a feeling you have a ton of really small linedefs grouped up and perhaps just 1 of them is missing a texture, therefore you get this only happening while moving.  again tho im not really sure because at least for me, missing textures in the map when played thru gzdoom turn into see thru lines or repeating flats.  that almost looks like the orange 64x64 box you see in the editor on surfaces that arent textured....

 

Also i noticed in the top pic it looks like you are using 3d floors to simulate the shelf "supports".  due to the bug happening exactly where those supports are, they could be involved, but its definitely not a "limit" of 3D floors.  I have a map with a sprial stair case with about 70 3D floors as stairs in a single sector and there are maps out there that use even more so im almost 100% sure is has nothing to do with how many 3D floors, but rather the vertices that comprise them