Sunrise animation

[davius3d]

I'm quite positive this must have already been asked around here, but I'm making some tests and getting decent results. Just not sure it *is* the correct way to go. And it rise some other questions too.

Why doesn't the sky turn really dark (almost pitch black, the desirable would be a deep purple) when you drop the sun below the horizon line?

My workaround was animate the sun intensity from 0 to 1 as it also rises. This makes the sky pitch black (which is something you do not really want) so I comped the VraySky with a VrayHDRI in add mode and dropped then at the environment slot. The HDRI I used was a deep dark blue, a sunrise sky.

Is this a "correct" way to do it? I feel it's not, but at least it wields interesting results, better than just animating the sun position.

Cheers,

David

[Svetlozar Draganov]

The sky will turn to a pitch black at some point when you drop the sun bellow the horizon line.
It won't happen immediately when the sun cross the horizon but if you continue dropping it lower and lower it will, the same thing actually happen in real world, sky stays illuminated long after the sunset.

[davius3d]

Indeed, thanks Sve! Although making tests I found that when the sun is really down, the sky takes a very deep blue tint and, as the sun goes up, it gets DARKER, and suddenly it gets orange-ish from one frame to another. I animated the sun linked to a Daylight system (just to help drive the hours) and made this animation from 4 am to 7 am. Notice it starts blueish, gets really dark and suddenly get's much lighter. Check it out:

https://youtu.be/bkWL0He2ORQ

[Neilg]

sun/sky doesnt work with the sun below the horizon, and none of the available light models are particularly good at handling the sun close to the horizon either. for animated sunrise / sunsets we use mix maps to blend between the sky & hdri's in order to take us through dusk.

[davius3d]

I did something I guess is similar to what you do, Neilg. I animated the Sun position and ALSO its intensity. Used a VrayCompTex and comped a HDRI and a VraySky together. The result is pretty convincing (deep purple/blueish colors to yellow/white sunlight) although I suspect it breaks a bit of the physics of the light. With a bit of love in AfterEffects and this will look very cool.