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Philbert
05-31-2019, 02:04 PM
I've got this texture of a starry sky that looks fine in the Image Editor and Photoshop but the render looks very pixely, like dithered. I've tried all of the different color space options. It's a pretty high res image, 5175 x 3375, saved from Photoshop as RGB. Although the original version the client sent me was CMYK, I converted it to RGB. This screenshot is VPR but it looks the same in an F9 render. Is there something I can do to fix it?

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prometheus
05-31-2019, 02:51 PM
how did you apply the background? as compositing background image, or textured environment..or other methods?

Philbert
05-31-2019, 03:02 PM
Oh yeah, it's a texture aied to a dome with spherical mode.

prometheus
05-31-2019, 03:15 PM
Oh yeah, it's a texture aied to a dome with spherical mode.

I would try how it looks first in simple background image, and also textured environment, could be some surface setting you have wrong, and what kind of material you have set..could be shading model settings etc.

If it looks good in textured environment and in background image, I reckon that would be the case.

Tim Parsons
05-31-2019, 03:34 PM
I've seen these images before from NASA - they are huge but they don't look good at all.

Philbert
05-31-2019, 04:01 PM
I would try how it looks first in simple background image, and also textured environment, could be some surface setting you have wrong, and what kind of material you have set..could be shading model settings etc.

If it looks good in textured environment and in background image, I reckon that would be the case.

Well I can test it in another scene or on another object but I can't use it on Textured Environment because I'm already using the new Physical Sky with a sunset. The dome has transparency on one side so the stars fade away and the sunset is visible.


I've seen these images before from NASA - they are huge but they don't look good at all.

Yeah well that's what the client wants me to use.

lardbros
05-31-2019, 04:19 PM
Is the image in the correct colour space? Why on earth would they have done it in CMYK??

Philbert
05-31-2019, 04:37 PM
OK I figured out something. It's the transparency. I'm using a gradient with "Distance To Object" (a null). If I disable the Gradient the star texture looks fine. However I need that transparency to see the sunset.

Dexter2999
05-31-2019, 05:43 PM
Why on earth would they have done it in CMYK??

Many times your contact person isn't an actual graphics person. I used to do logo work for conventions and would often get graphics formatted and sized for print work.
Once I asked for a logo as EPS if possible. The file they sent me was a thumbnail formatted as PNG that had been placed in Illustrator and saved as EPS. (Still not a vector graphic. Not scalable. Thanks for playing.)

Philbert
05-31-2019, 06:00 PM
Like I said I tried all of the color space options, they all have the problem.

peebeearr
05-31-2019, 08:15 PM
OK I figured out something. It's the transparency. I'm using a gradient with "Distance To Object" (a null). If I disable the Gradient the star texture looks fine. However I need that transparency to see the sunset.

Phil, maybe try a different blending mode while still having the gradient in there.

Arthur

Philbert
05-31-2019, 10:55 PM
Oh yes, the blending modes was the first thing I tried long before I saw the gradient problem. I think it's something else in the scene. I recreated the texture and the gradient on an object in a new scene. And it looked fine, so I did Load Items from Scene and loaded everything from the original scene and the texture got messed up. So I may have to load things one at a time to see what causes it

prometheus
06-01-2019, 07:16 AM
If I got the time I will try with dome geometry, I did a lot of experiments previously with similar stuff, mostly trying a mix of cloud spherical images and godrays, this required two domes ..one for color, and one for transparancy to produce the godrays when I had a volumetric light over the dome, the domes was paranted to eachother so once I rotated the dome to get a desired view, it would all stay connected..godray producing cloud dome map and the color map .

You could also try textured environment with physical sky, see image, where I expanded the main starry space canvas, which made bottom half transparent..and then I paint blurred the edge on the star sky to fade in to the transparent part, saved as TGA.
Once in layout I put textured environment beneath the physical sky.

Now the result isnīt realistic since when do you see such a sky with stars and nebulas...not here on earth anyway, and the blend should be much longer and softer, but you get the idea, I think you should be able to do this with geometry as well...I may test it later if I got the time.

https://forums.newtek.com/attachment.php?attachmentid=145124&d=1559394960


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prometheus
06-01-2019, 07:35 AM
another sample with sun in the middle, and some additional Global volumetric scattering, set anisotrophy very high, in this cas 0,95 for glow around the sun.

You can also add sunflare star filter, but you may want to add the sk sun motion, but apply sunsky in environment first in order for sk sun motion to recognize it, then after selecting the light in sunsky environment ..the flare star filter will snap to the suns location, then you deactivate sunsky but keep the sk sun motion modifier


https://forums.newtek.com/attachment.php?attachmentid=145125&d=1559396063

https://forums.newtek.com/attachment.php?attachmentid=145126&d=1559396105

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Philbert
06-01-2019, 06:05 PM
I solved my problem. I'm not sure why but some lights that shouldn't have even reached it needed to be turned off. I also turned the surface's Luminosity to 100% and the Diffuse down to like 15%. Here's an F9 render. The client loves it.

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lardbros
06-01-2019, 08:36 PM
Very odd... Did those lights have any falloff on them?

prometheus
06-02-2019, 05:43 AM
I solved my problem. I'm not sure why but some lights that shouldn't have even reached it needed to be turned off. I also turned the surface's Luminosity to 100% and the Diffuse down to like 15%. Here's an F9 render. The client loves it.

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you should have diffuse to zero, no texture or value at all, add the map in the color channel and set luminosity to 100&