Horizon Haze (atmospheric perspective)

[dotcommer]

Next project I'm working on is a night time ocean scene. I'm trying to figure out how to get that hazy look on the horizon, but I can't get something decent. I've been playing with a cube parented to the camera with inverted normals and a specular scattering medium applied to that. The fog effect is either way too intense almost like pea-soup, or its nonexistent. I can't get a happy medium, or define an area where the fog should start. It also ends up blanking out my night sky which has a texture of stars on an Octane Sky object (a separate issue I'm not sure how to fix).

Here's a reference image of what i'm trying to accomplish. Look at the horizon and notice the falloff of the haze. I'm trying to get that effect.

Any ideas?

[glimpse]

Actually this is what I'm interested too =) trying to experiment with seascapes theme at the moment (like in first shot here). Original idea was to make a distant fog/haze, but I have to cheat..-it came to be harder get a realistic output than I originally thought =) but I've hooked on the end result & looking to nail down this now without any cheats =)

[martincarlson]

Did something similair when experimenting with this:
http://render.otoy.com/forum/viewtopic.php?f=5&t=45380

I used the fog volume technique described here:
http://render.otoy.com/forum/viewtopic.php?f=9&t=38645

[glimpse]

Did something similair when experimenting with this:
http://render.otoy.com/forum/viewtopic.php?f=5&t=45380

I used the fog volume technique described here:
http://render.otoy.com/forum/viewtopic.php?f=9&t=38645

Hi, Martin, Thanks for links! =)

[dotcommer]

Yeah, I'm using the same technique right now; camera bubble. But I can't get a night scene going with it. Not to mention once I use this technique, it completely blocks out my stars HDRI that I'm using in the octanesky object. I'd like to have some clouds, stars, and a moon, but at the moment, I can't even get the night sky working correctly. Should I be setting it up with a daylight object and change the sky and sun colors to black for night and warm yellow for the moon? If I do that, I can't really texture the moon... So many questions and I don't have enough experience to figure it all out.

[martincarlson]

What i've found out is that the Phase setting in the scattering node makes HUGE difference. Play around with that.

Also how high are your fog box? Don't make it too high. Just above your camera FOV. And your stars will shine.

Assume your camera bubble has inverted normals. Else things fuck up.

Also play with fog materials opacity setting. Float value or gradient texture.

[aoktar]

No need to make the fog box smaller. Think on big sizes of objects. Decrease the scale of medium, it's a multiplier. And use a daylight+mix with star environment texture with high power of images as 10-50. See what's happening.

[dotcommer]

Here's my scene file for anyone to take a look at. I got a little closer with using a gradient in the opacity channel, but then when I look up, I see a weird projection of the fog on other faces of the bubble. Also can't seem to smooth out the transition of the moon's reflection with fog. It still looks really sharp.

Am I going about this the right way? Or should I be creating my stars, moon, and clouds in one large HDRI and putting that in the OctaneSky Object?

[aoktar]

see the image what i have achieved via a fog box. It's illuminated by a hdr image

[dotcommer]

Is your scene just really really large? Are you using the camera bubble technique or are you encompassing the entire scene in one large fog volume?