How to make texture tile seamlessly in circle sector?

[Nash]

I have a perfectly circular texture which I created via GZDoomBuilder's "Ellipse Drawing" tool. I have made sure to make the horizontal and vertical distance 1024, and created a 512x512 texture which SHOULD tile perfectly... but it isn't. :/

[Gez]

You mean, wall texture? Remember the formula for a circle's perimeter is diameter times pi. So with 1024, you have a perimeter of approximatively 3217 units, give or take a few as dictated by the lack of precision of the sector compared to an ideal circle.

[ReX]

If your circle's circumference is not a multiple of the texture length (in this case, 512), then you can insert a suitable texture in between to hide the texture-tiling problem. For example, use SUPPORT3 in the middle of SP_HOT1. I know this does not properly solve your problem, but there's no other way to prevent the "seam" from forming on a wall whose length is not a multiple of the texture.

Another way to do this, is to adjust the radius of the circle so that the circumference becomes an exact multiple of the texture length. This could result in your horizontal and vertical linedefs not falling on one of the grid lines, but this may not be important to you.

[Gez]

With a diameter of 978 map units, you get a perfect circumference of approximatively 1024*3.

[Nash]

The formula that Gez posted solved my problem.

... except I had to abandon the thing I was trying to do when I made this post. I'll just explain here.

I was trying to replicate Skyrim's skybox, based on my observations anyway. The circular sector would have drawn a side-scrolling cloud texture, and then a translucent 3-d floor would have drawn the flat sky. It had to be a 3-d floor because there was going to be 2 layers of "flat" clouds, and stars would have been drawn behind (above) the 3-d floors.

It was all in vain when I found out that GZDoom can't render 3-d floors with smooth alpha textures. Probably related to polygon sorting issues with the renderer, the same reason we can't have model textures with smooth alpha or sloped translucent 3-d floors.

[Gez]

Have you tried with [wiki]portal[/wiki]s?

[NeuralStunner]

Have you tried with [wiki]portal[/wiki]s?

"Gez Johnson here..."

[SuperCrazyMan]

Have you tried with [wiki]portal[/wiki]s?

Doesn't work either, unfortunately.

[Nash]

Last I messed with portals in skyboxes, it HOM'd like nobody's business. Anyway, I doubt it woud work anyway since I needed to use textures with smooth alpha (in other words, a 24 bit PNG with alpha) and that's just not going to work for flats.

I would have also just used a sky dome model but, again, transparency issues.

[Minigunner]

HIRESTEX (old format) has "force32bit", I believe. E.G. "define <graphic> force32bit <width> <height>"
Also, there's the CopyAlpha render style in TEXTURES.

[Graf Zahl]

HIRESTEX (old format) has "force32bit", I believe. E.G. "define <graphic> force32bit <width> <height>"
Also, there's the CopyAlpha render style in TEXTURES.

That won't help here. Apparently for flats the alpha threshold which is needed to render textures with fully transparent part is not switched off if the texture itself contains alpha.

[Nash]

So is this a bug? Can it be fixed?