Author Topic: White dots in image  (Read 497 times)

Offline Eric Johannsen

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White dots in image
« on: June 10, 2017, 07:30:54 AM »
I'm trying to render a .obj but end up with some white dots. What could be causing this?

Thanks!

Offline Dune

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Re: White dots in image
« Reply #1 on: June 10, 2017, 11:27:40 AM »
They are opacity dots, I am almost sure. Check the opacity tab of the object's default shader(s) for textures that do not need to be in the opacity input. Sometimes there's alpha checked while there is no alpha, e.g.
I see you have unpremultiply checked also, better uncheck that.
And for the transparent object you could also (or maybe better) use a glass shader. Unpremultiply should be disabled too.
Oh, and there's a luminosity input but zero luminosity, so either delete the input or give it some perhaps needed luminosity.
« Last Edit: June 10, 2017, 11:32:07 AM by Dune »
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Offline Eric Johannsen

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Re: White dots in image
« Reply #2 on: June 10, 2017, 06:04:26 PM »
Unchecking unpremultiplied color did the trick.

Do you have any suggestions to make Jupiter's colors pop? I have a texture map of Jupiter (published by NASA) projected onto a sphere. The colors look very muted. Also, any tips to make the swirls look sharper? That's the highest resolution texture map I could find, but it still looks a bit pixilated to me. Finally, I tried experimenting with an atmosphere around the planet, but it seems the atmosphere model in TG assumes an earth-like light scattering model. Is there a technique to get the yellowish atmosphere that would fit better to Jupiter?

Thank you for your help!

Offline Ethrieltd

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Re: White dots in image
« Reply #3 on: June 10, 2017, 09:33:52 PM »
I have a link to a 6K version, dunno if it's any better.

http://planetpixelemporium.com/jupiter.html

Would negative figures in the ozone factor settings make the atmosphere more yellow? It's all tied into to the other atmosphere settings so I'm not sure how that would work.

Offline Eric Johannsen

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Re: White dots in image
« Reply #4 on: June 10, 2017, 11:54:08 PM »
Thanks, Ethrieltd. That's the image I used. I'll try your suggestion for the atmosphere.

Offline Dune

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Re: White dots in image
« Reply #5 on: June 11, 2017, 06:10:40 AM »
Pop the colors and more definition more would be a Photoshop thing.
Some experimentation with the atmo settings may work, indeed. Or disable the atmo and use a high, thin, colored cloud, perhaps.
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Offline Dune

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Re: White dots in image
« Reply #6 on: June 11, 2017, 01:44:46 PM »
Pop the colors and more definition more would be a Photoshop thing.
Some experimentation with the atmo settings may work, indeed. Or disable the atmo and use a high, thin, colored cloud, perhaps.

I did some testing and with a default shader you can fake clouds. Color input and greyscale bump/displacement input, as shown in this screendump. Play with values. I added another planet just for an atmo (only render atmo), and changed the color of the blue sky to a yellowish color, raised ceiling, and set haze to zero. Enough to experiment with.
Result, see here: http://www.planetside.co.uk/forums/index.php/topic,23242.0.html
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Offline Eric Johannsen

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Re: White dots in image
« Reply #7 on: June 12, 2017, 04:59:36 AM »
That looks great! Thanks, I'll experiment along the lines you suggest.

Did you manipulate that texture in Photoshop or did it render in better colors using your approach? How is Image Map Shader 01_1_BU different from Image Map Shader? Did you just convert the Jupiter image to grey scale for the bump map?

Offline Dune

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Re: White dots in image
« Reply #8 on: June 12, 2017, 05:59:52 AM »
No, it's the texture as it was. But it might be a different map I once downloaded from somewhere, as I have 3 of them, the others hazier indeed. So you might want to enhance in PS anyway.
They are 2 different image maps indeed; one color, one I made greyscale and took through Pixplant to make a displacement/bumpmap of it. So the one saying 01_1_BU is the bumpmap, obviously.
Btw. I don't know if you're familiar with node working, but I recommend naming all nodes you use with an easy to understand cryptic title. When the number of nodes increases it might get too complicated even for yourself to understand what all the nodes do (if you have 20 power fractals for instance).
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