GZDOOM fun: skybox issue?

[Eponasoft]

Decided to try out a GLDEFS skybox. Looks great, except one little detail...

http://www.eponasoft.com/skyboxwtf.png

Figured maybe it was an issue with SLADE3's conversion, so I converted it before importing it... but it still has the same issue. The images are fine... each is a clean 1024x1024 image, no errors of any kind. Is this perhaps a hardware limitation of my machine, or is this really a buggy bug of some kind? Any ideas?

EDIT: I'm gonna err on the side of "hardware limitation"... I reduced the images to 512x512 and didn't have any problems.

[D_GARG]

so, was the resulution the problem then?

[bytor]

ha! I was just messing with a skybox (ZDoom UDMF) early this morning and ran into the same thing. The problem I was having was with the ceiling. Kept giving me a tutti-frutti(?) effect until I tried shrinking the image down to 512 x 512. Then I couldn't figure out why front/back/left/right wouldn't line up, so I placed a big "F" towards one side of the ceiling image and discovered that the ceiling was rendering mirrored. Also, got a seam if it wasn't placed within the 512 grid.

[Eponasoft]

I was seeing the sky backwards as well... just flipped the image and it all worked like a charm. :)

[Graf Zahl]

bytor said:

so I placed a big "F" towards one side of the ceiling image and discovered that the ceiling was rendering mirrored. Also, got a seam if it wasn't placed within the 512 grid.

That was an early development error. You can fix this by adding 'fliptop' to the skybox definition.

As for the texture glitch, what hardware do you have? No idea if this is a hardware problem or some bug in the texture creation code.

[Gez]

For GLDEFS skyboxes, you can use the "fliptop" keyword to handle the mirroring for you. For a sector-based skybox, I figure it's simply because that's how the flat would be rendered. (Place the same texture on both the floor and the ceiling, and notice how the ceiling mirrors the floor perfectly.)

Do not hesitate to post bug reports on the ZDoom forum if large dimensions cause problems.

[Eponasoft]

I tried fliptop but it flipped it on the wrong axis. It wasn't a big deal though... mirroring the image worked fine, so I wasn't concerned.