Universal Forum Archive

According to the settings sky rendering the texture either once or twice across the sky is supposed to form a dome.

When I launch the house (neat trick that BTW) I find that my sky is rendered more like an infinitely tall cylinder to where a checkerboard pattern (which I used to figure out how to crop/paste/fold/bend/mutilate my sky texture to wrap neatly around the "dome") has the top line of checks stretching to infinity (and beyond).

If I use a picture like a wrapping cloudy sky, I find that near the top my sky streaks infinitely into space.

Around the horizon about ¼ of the way up from the horizon my sky looks like a ceiling meeting a cylinder wall, the walls (horizon) are rendered oddly against the “ceiling”.

I was hoping to use one of my 47 sky boxes to render the sky, I have a neat one with a set of rings as if you are standing on the surface of Saturn, and one with a near planet against the horizon to where you see ¾ of the planet (the rest below the horizon) however these images are warped and twisted weirdly not only stretched horizontally, but bent at the bottom and streaking infinitely straight up.

I have tried having a square image, one that is a ratio of 1:3 (eg 500 pixels tall, 1500 pixels wide) I have tried 1:4, 1:8. etc.

Is there a rule of thumb on the image ratio that renders the sky neatly and evenly?

It's probably about time I re-did the skydomes - I imagine they're not as accurate as they should be. However, using domes rather than boxes, that stretching is just a natural consequence of trying to get the majority of the detail in the areas players will see most (if not all) of the time.

For example:



That's the mapping for one of the sky variants. I don't know if you're familiar with "standard" mapping for a sphere, but you'd normally expect the "lines" of polys to be evenly distributed on the template. On the skydome, they're not: so we have squishy mess at the bottom, squishy mess at the top, and massive amounts of detail in just a couple of "rows".

What this means is, your sky texture should blend to a solid colour at the top and bottom - typically, to a generic "horizon" colour at the bottom (a dark black/green, for example, if you have a grassy world) and a generic "sky" colour at the top (very light or dark blue, perhaps, if you're using a generally blue sky).

The ratio of the image you use doesn't really matter, although it makes sense to use wide images (1024x512, 2048x1024 etc) because that's how the dome was mapped originally. Ideally your images will wrap left to right, especially if you use "textured once across the sky" settings. If you use "textured twice" settings, you can get away without left-right wrapping, because the code will mirror your texture for you. However that can create some strange effects depending on the detail you have in the texture (two suns, for example).

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A picture is worth a thousand words and just seeing this map answers all my questions and most likely will lead to my perfecting the sky on my world. Now that I know where stretching and crunching takes place.

Thanks for the information!

Cheers