Filtered Sun Example

Started by WAS, July 31, 2018, 01:31:41 PM

Previous topic - Next topic

WAS

There was an absolutely stunning sunset last night that I tried to recreate in Terragen, though I quickly found out that masking the sun disc is actually very challenging, and I was unable to achieve the rich neon colour of the sun (it was pretty neon purple red), I also found that Terragen doesn't correctly render GI for sunsets. At a sunset with high haze density, the majority of the light wasn't coming from the sun (that you could look directly at, and wasn't painting colour on trees still lit by the sky blue) but ambient light from the sky. I couldn't mimic this that well either. Probably could simulate it with upping colour from atmosphere or something with less sun main intensity. Didn't try.

Weird black breaks in the surf, not sure why. Possibly problems with the Smooth Shader again.

However it is a pretty nice scene and the sun is pretty well filtered.

(Can this be moved to file sharing? Probably more appropriate actually.)

Matt

#1
Regarding GI, it should be able to do that. Increase the density even further and increase exposure if it becomes too dark.

Bear in mind that how your eye sees the sun at sunset is not the same as what a camera (or renderer) can show. You have to underexpose to show the colour of the sun but to see the GI effect on land you have to expose much higher and that will wash out the sun.
Just because milk is white doesn't mean that clouds are made of milk.

WAS

#2
Quote from: Matt on July 31, 2018, 05:44:54 PM
Regarding GI, it should be able to do that. Increase the density even further and increase exposure if it becomes too dark.

Bear in mind that how your eye sees the sun at sunset is not the same as what a camera (or renderer) can show. You have to underexpose to show the colour of the sun but to see the GI effect on land you have to expose much higher and that will wash out the sun.

I wasn't able to take a picture of this sunset because my camera is my phone, which is also my modem. However, my camera's sensor is pretty rigged to translate colours over like a human eye, and does as good job. Sunsets will look the same in colour. However, you're right, because of brightness, the terrain is subsequently way under exposed. That and the FOV is all different so you end up with a rather small sun among a wide angle shot.

I was just making a note that at default GI setting under a sunset with haze, there seems to be primarily light coming from the sun, when it's actually so filtered you can look at it like a light bulb, and the sky is producing the main ambient light, still being relatively light blue. I had to use two suns to "shed" some of the colour, but unfortunately with the disc filter, it has to have some light settings on to achieve it's effect, which subsequently "paints" the lighting from the sky form blue to pink. 

This scene is definitely under exposed from what I saw. This post example is more what the sun itself looked like but still not right, it was more solid and neon. Was pretty damn impressive. Rare sight.

Matt

If the sun is still the dominant light source then I believe it's because you need more haze and/or bluesky density. It might be also be a more localized effect in the direction of the sun, which you could simulate with a cloud layer (perhaps using a darker colour and also using a blueish final density multiplier if this was being caused by smoke or other very fine particles in the atmosphere - which it probably was if the sun was so red).
Just because milk is white doesn't mean that clouds are made of milk.

WAS

Quote from: Matt on July 31, 2018, 07:19:46 PM
If the sun is still the dominant light source then I believe it's because you need more haze and/or bluesky density. It might be also be a more localized effect in the direction of the sun, which you could simulate with a cloud layer (perhaps using a darker colour and also using a blueish final density multiplier if this was being caused by smoke or other very fine particles in the atmosphere - which it probably was if the sun was so red).

I tried cloud layers, but it changes the horizon too much, and localized just didn't have a good enough fall-off to not stand out. I tried making a orb and positioning it in the far distance centered around the sun.

Even tried direct/enviro light modulators in the clouds. Just couldn't get a strong neon filtered colour, without destroying realism (similar to post lol).