2
$\begingroup$

So continuing from my many Earth posts, I've now come to the dilemma of my night side. I'm currently using a texture that's around 52000x32000 which is perfect, can't go lower than that, and it was pre stitched together, however, the land is dark blue. I want this to be completely gone with just the lights showing. I remember seeing someone post on Blenderguru's Earth tutorial that they managed to do it but they couldn't remember the process.

Is there any chance anyone out there would know how? Rule out photoshop or finding a new texture as I've tried both. Other textures online are either of a lower pixel density or need stitching which my computer can't handle. I've tried removing the darkness and keeping the lights in photoshop with the already stitched image but my computer can't run it with such a high amount of pixels.

I've also tried messing with the image adjustments within Blender but have had no luck.

enter image description here

enter image description here

$\endgroup$
  • $\begingroup$ looks pretty neat, maybe script something to hide the areas when they are dark and just use a (separate) texture with the lights $\endgroup$ – Jonathan Mar 30 '15 at 15:03
  • $\begingroup$ I think I need clarification -- do you already have a nighttime image that you just want darker, or do you need to create the day/night transition from scratch? Also, can I ask why you need a texture that is so extremely high-resolution? $\endgroup$ – smashuu Mar 30 '15 at 16:11
  • $\begingroup$ @smashuu The night time image you see in the two pictures is the one I'm currently using. The transition isn't the problem, the dark blue is. The night time texture features the lights AND the dark blue land you see, I just want the lights to show. I deal with a lot of close shots for animations a lot and in order to produce the best looking image you NEED incredibly dense texture maps. I've messed with lower ones but they leave too much low quality blur and don't produce good enough results. $\endgroup$ – Stewie Mar 30 '15 at 16:12
  • $\begingroup$ have you tried the editing RGB curve of the image $\endgroup$ – Chebhou Mar 30 '15 at 16:23
  • $\begingroup$ @Chebhou Not yet as I messed with the RGB setting in the Texture panel and, although I removed the blue, the lights turned a horrible red and some had lost their quality so they ended up looking like sploges. I'll give it a go. $\endgroup$ – Stewie Mar 30 '15 at 16:30
3
$\begingroup$

The RGB Curves node sounds like what you are looking for. It functions almost exactly the same way Photoshop's curves command does, so it is very useful for pushing light and/or dark values. See the image below for a quick example, where I left lighter colors (on the right) more or less unchanged, but drastically darkened anything below about the halfway threshold.

RGB Curves node example

The RGB Curves node is also handy for tweaking the exposure levels of a background photo/HDRI without having to modify the original file.

$\endgroup$
  • $\begingroup$ Thank you so much! I've been researching for days on solving that, just need to give it a few more tweaks so it doesn't look like a nuclear war has broken out and it should look great! Thanks! $\endgroup$ – Stewie Mar 30 '15 at 16:47
3
$\begingroup$

Since you are using the blender internal, you can easily tweak the texture colors and brightness.

In the texture settings for your night texture, open up the Color section. There you will find values for each of the color channels pluse Brightness, Contrast, and Saturation.
Because you want to darken the dark region, and keep the lights bright, start by increasing the Contrast. Next, to crush the blue channel, lower the B and slightly increase the R and G. texture settings

$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.