Time of day thoughts and ideas

[Mr Whippy]

Just a thought...

Time of day, or TOD, is getting quite nice now.

I was thinking however that Ruud's implementations of colour variances and so forth throughout the day are not always ideal. I feel midday is too yellow, and dark nights are too 'light'


Anyway, I feel generally Ruud will never get his right because there is no right or wrong. Different places in the world will feel different. A city might be best with an orangey ambient glow in the night for example. These are things artists can tweak to set a mood.


Also, mie and rayleigh will change as the time of day changes, and ideally we should be able to artistically set these too.


I still believe Racer should have an auto mode, no doubt, but for those who want to delve deeper, setting them up would be nice.


So my quick thought was a LUT (look up table) drawn in curved. Have four of them. One for ambient vs time of day (0-24 on X axis, ambient light in Y axis (not sure how you'd do r/g/b yet))
Then have one for diffuse, like above.
Then have one each for mie and rayleigh.

Now when we use TOD, which as said I think is getting nicer if you use really good day/night sky textures, then you can set some lovely dawn/dusk transitions. Some track makers may not want to, that is fine, but the variety will be really nice to have!


Another addition is that currently TOD defines the sun position to the centre of the earth?

Adding lat/long and day/month, and/or even year would be nice, so we can get low-slung winter sun transitions across the sky.


All this is either simple LUT's rather than hard coded variables, or just improving the maths and adding a few constant inputs (for lat/long and date/month)



A more complex further addition, for fun, might be to use the lat/long inputs to control the weather at a location from internet resources, so if it's raining, turn on rain. If it's cold, change the constant in Racer.ini (may be useful in future for engine power and tyre grips?!)



All cool stuff


But LUT's for the 4 variables, diffuse, ambient, mie, rayleigh, would be really nice. My only thoughts are how you'd define rgb for the diffuse/ambient... hmmmm. Makes it less easy unless we have 3 curves for diffuse and 3 for ambient


Dave

 

[Stereo]

So my quick thought was a LUT (look up table) drawn in curved. Have four of them. One for ambient vs time of day (0-24 on X axis, ambient light in Y axis (not sure how you'd do r/g/b yet))
Then have one for diffuse, like above.
Then have one each for mie and rayleigh.

Might be easier to consider it in HSV form, then convert to RGB? It seems to me that hue/saturation/value splits up the lighting in a more sensible way than RGB, for editing purposes anyway. I think HDR is also simpler, you only need the higher range on 'value'. You could even use "real" lighting amounts for the value, then.

You could also just have a 1x24 pixel image with the rgb colours for each hour. Or larger if you want finer control over the transitions (clear air drops from sunset to darkness a lot more sharply for example).

 

[Some1]

I'm lazy and would really vote for a system, that given a reasonable amount of inputs (lat, long, TOD, date etc), calculates the correct lighting values automatically. Although, I suppose, one could create such a tool for manual LUT's as well or something...

 

[Mr Whippy]

LUT's are done with curved... you could add as much detail or as little as you liked...

It's more for artistic preference.

Every sunset is different, as is every sunrise. Mie/rayleigh and atmospheric influences that change the colours, will all make for nice per-track conditions

If we use the TOD built-in, no matter how nice it gets, every sunset will look the same. There needs to be some per-track tweaking.

Yes, right now we can set a track as we want it at a fixed TOD, but to be really honest, if TOD can have the curves suggested, and I can set my track perfectly for my vision of a 'perfect day at XYZ track' with a sharp crisp clear morning, and a lovely deep hazy orange sunset... then I can't see why I'd just not use TOD for my track releases.



I think it's at the tipping point where if it has a few more controls I'd use it happily. It's so close to working how you would want it now really.

If it continues to do weird things like having yellow midday sun and a way too bright night-times, then I won't be using it for a while yet, preferring to author a fixed TOD.


Just been playing in-sim and it is good now, the shadows add SO much more authenticity to the time of day!


Just want to try it on swiss stroll now, but getting the shaders all nice is taking time!

Dave

 

[Cobra]

I like the idea, and the method looks good. As you said, each place in the world is different, so for me to drive on Swiss Stroll and have the TOD as is there...even though I am Canadian.....it would be great-like I was there in Switzerland. It would give a virtual feel-like mixing Google Earth and Racer. :wink:

I am using 0.6.5.4, so I may not be able to enjoy the idea should it come into a reality, but I think it would be cool!

 

[boomer541]

Good luck with the shaders for Swiss stroll! You might even try the shaders for Norway which gives about 1500 kb of Qlog shader errors, LOL!

My 2nd creek required 57 shaders one for each material texture image, and there was one that won't work right no matter how I try!

Your lighting ideas are good and I hope Ruud is watching!

 

[mdbobbo]

Dawns over Hamilton NZ

I love taking pictures of dawns and other views from around my district Waikato New Zealand, If only I lived on a hill to get panoramic views of dawn and dusk I'm be right in my element.
In the mean time take a quick squiz (look) at these few images I have made from mostly one location each morning in Hamilton New Zealand just to show what a beautiful real world scene does look like :kewl:
http://my.pho.to/mdbobbo/s1/albums/hamilton_dawns/

 

[Mr Whippy]

Those pictures just inspire the idea of LUT's for TOD even more!

I've just been playing with mie/rayleigh/extinctionfactor in Racer and getting some stunning sunsets and sunrises, warm orangey glows that make the skybox horizon go deep orange, to cool wintery feeling blue icy mornings that feel bright and cold!


The current TOD curves and static mie/rayleigh are so limiting...!


Ruud, how hard would it be to add LUT's for mie/rayleigh, and sun ambient/diffuse?

Maybe even something curved can't use, but looks like a CSV kinda format... ei:

0000, 0.5, 0.001, 0.001, 0.25, 0.25, 0.25, 0, 0, 0
0600, 0.5, 0.002, 0.002, 0.5, 0.5, 0.5, 1, 1, 1
1200, 0.25, 0.001, 0.001, 0.5, 0.5, 0.5, 1, 1, 1

Where we have:

TOD, extinctionfactor, mie, rayleigh, diffuse rgb, ambient rgb


Adding lat/long and month/day would also be pretty cool!



Dave

 

[Raphael Buthmann]

hm, I think separated curves could be better. =D

 

[Mr Whippy]

Curves would be better then you could smooth them out and things...

I'm just thinking of an elegant way to have them all in one file so you can see them all interact with each other, and also the difficulty with having the rgb curves that would be needed for ambient/diffuse colour/intensity...

I think that would be better, but it's just the extra workload for Ruud to make an app like that for us.


For now at least, a simple CSV or similar LUT would offer the power... it wouldn't be ideal, but it'd get us going!

I just think TOD as it stands now is a rough diamond. Until it's polished it's rather un-appealing to use for anything really... but we can polish it many ways, and adding simple LUT for now would give us the ability to polish it nicely... it'd just be a less than perfect process (but hey, what in Racer is perfect right now?)

Dave

 

[Stereo]

I chose a bad week to be away from my desktop I'm thinking maybe this can be mocked up in the new scripting system (check current time, reset lighting values based on interpolation of some definition) but I have no way to try it. So I don't know if the time is available to scripts, or if this is a reasonable way to apply them. The TOD already handles sun position automatically, it just needs a little assistance with the rayleigh/mie and ambient/diffuse colors.

 

[Mr Whippy]

Yeah, TOD is pretty good.

It needs global position though due to varying lat/long having different sun movement through the day, and then I guess day/month to give a rough movement for winter vs summer trajectory.

That is pretty simple from what I have heard, the maths is widely available iirc. Just plugging those variables into the track special.ini I guess...


The harder bit I suppose is helping TOD along, hence having LUT's if you want. Personally I'd prefer Ruud to just give up the reigns on this one and leave artists to find good values, rather than carry on with a hard coded or 'hidden' algorithm that won't ever be able to do the subtle different things people want for different tracks and moods etc.

Ruud has done this in the past and when he removes hard coded variables to artist control it generally results in much better content because authors can find the perfect solutions for their needs, and refine the best practice methods etc

Dave