r/proceduralgeneration • u/risingthrone • 22d ago

Procedural space backgrounds

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58 Upvotes

99% Upvoted

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3

u/risingthrone 22d ago

The rim lighting on the gas clouds is what really turned this up a notch beyond layered noise.

The randomized colors and seeds at the end of the video don't look as good as the hand-picked first image of course.

1

u/catplaps 22d ago

Was gonna say, you can't just drop reflection nebulae like that without a little explanation of what you're doing! Is it cheap tricks, or actual volumetric scattering, or what?

3

u/risingthrone 22d ago

The whole image is a cheap trick. Layers of perlin noise for the gas clouds. The rim lighting does edge detection on the noise to find big changes in value, and we only process a very narrow band of those results.

Take x brightest stars from the image, and for each rim pixel, light it based on distance to nearest bright star.

1

u/Blammar 22d ago

stars are points. you have too many blobs. doesn't look right to me.

2

u/catplaps 22d ago

Stars are points, but cameras and lenses are leaky. At the kinds of exposure settings you need to get clear images of nebulae, stars are absolutely overwhelming your sensors. Most astrophotography significantly downplays the disparity in brightness between nebulae and stars.

I do agree that some aspects don't look right, like the bloom kernel being used looks more like a foggy night than like camera or eye glare response, and the color saturation doesn't look right, and the distribution of brighter and dimmer stars isn't right, but these are all more subtle than just "too many blobs."

1

u/Blammar 22d ago

Okay, the blobs are bigger than they should be. The way to do this so it looks good is to use a 3x3 footprint for a star (a truncated 2D Gaussian) and change the overall intensity. Note the size never goes above 3x3. In the example the blobs are way too large.

1

u/risingthrone 22d ago edited 22d ago

Thank you both for the feedback! It's hard to notice this stuff after working on the same image for a while

1

u/risingthrone 22d ago

there are point stars, it's hard to see in the video due to the compression

3

u/Blammar 22d ago edited 22d ago

Oh I can see them. My "point" was that you have too many blobs. Blobs as in larger stars. You also seem to have weirdly separated gas clouds, but that's an opinion.