Northern Lights

[Vega59]

Hi Guys

Been away from T2 for a couple of months and I'm now trying to get back into it again.

I'm looking for some help on this image I'm constructing.
I'm having some difficulty in creating the northern light on this snowy mountain scene which was donated to me by DandelO a few months ago.

I found an image titled Northern lights that someone else created using altocumulus cloud layer within the foum, I tried to copy the inputs
however it did look good at one time, but I dont know what I have done as it has gone to pot!

Can some one help

Cheers

Martin

[dandelO]

384 atmo' samples and cloud quality = 50 screams out to me straight away! But maybe your setup requires it, dunno yet. Back in a bit...

[dandelO]

So, drop your atmo quality samples to '16' and the cloud quality to '1'. When you've done that, visit the render tab and click 'edit sampling'. Select '1/4 first samples' or, just uncheck 'customise sampling', both will have the same result, you'll notice a massive increase in speed. This might be a bit grainy but just increase cloud 'quality' by '0.25' to '1' incrementally until it looks smooth, you really shouldn't need '50' for this, maybe 4 or 5 in the quality field, maximum.

I changed a few things in the cloud/fractal nodes here, mainly removing the first fractal and the multiply node, you can get a decent mask by using one big fractal and then apply that as a second, smaller fractal's blend shader only. I'll upload it once I've fixed it up but start off by doing the above, test renders will be a lot quicker and easier that way to begin with.

[Vega59]

Thanks mate!!!

I have tried what you told me and its working much better, just getting a test render underway at the moment.

I have used an illumination command to add some light to the mountain in the foreground, just thought it would bring out the detail in the
Image and keep the view interested. Just very subtly at a low altitude and very low strength

I'll up load a test render shortly.

Thanks again!

Martin

[dandelO]

Just done the same thing here too, I moved the cloud back from near the camera as the borealis were in front of the mountain, once I don't that there's pretty much no light on the ground...

[Vega59]

Hi Again

I switched to top view mode, zoomed out selected the cloud layed and moved the cross hairs back so that the circular
dotted line was behind the mountain, is that the correct way to move the cloud layer?

Martin

[dandelO]

Aye, that'll do it. I did that and then blended the nearer parts of the localised cloud out with a distance shader too. Don't have much time to muck around with it just now but the render and quality settings should give you a better place to start from.

[Vega59]

Thanks mate

I'm just rendering a quick preview of your settings mate.

I have shifted the position of the sun so its opposite the camera and lowered the elevation to zero, reduced the strength to 0.5.

this has give a very intense glow that's very striking!!!!!

I'll get a look at your settings and see where I'm going wrong.

Thanks for your help I'm extremly grateful

Martin

[dandelO]

Welcome, Martin. Always remember, there's usually only very rare times when you'll need to exceed a cloud quality of '1'. This is probably one of those times but you generally won't need '50' very often, if at all. In my last Saturn animation render I had to use a quality of '15' due to the very extreme cloud layer settings that I used to make those rings, that's really pushing it up high, in my opinion and is rarely ever advised.

Atmo' samples of 8, 16, 32 or 64 is nearly always enough in most scenes too where atmosphere noise is problematic. And using 'RTA' in the render node with a respectable AA level means you can get away with much less samples.

[Vega59]

Heres a quick render of the latest image with the sun below the cloud!

Its too intense so I have reduced the sun strength raised the radius and height of the clouds.

I'll upload again later.

Let me know what you think

Martin

[Vega59]

Hey Mate

What you think of this attached image?

Cheers

Martin

[Tangled-Universe]

That looks pretty good Martin...

I still see some grain in the northern lights so you may consider increasing cloud samples a bit more.
I don't know at which settings you rendered them and with or without RTA so I can't really estimate how much you'd need.

Cheers,
Martin (whoohoo...a "martin only" topic here )

[Vega59]

Hi Mate

Cheers for the nice comment!

I only rendered it using the quick render option, I'm doing a full render as we speak......

I'm very new to terragen, so slowly getting to grips with the program.

I'll update the latest render when its complete, I have adjusted the camera angle slightly and increased the foreground illumination
a litlle.

Cheers

Martin

[Vega59]

Final Render

Any thoughts guys? How can I make the shot look more photorealistc?

Cheers

Martin