Time of Day is a package to render realistic dynamic sky domes with day and night cycle, realistic celestials, dynamic clouds and physically based atmospheric scattering.
I just uploaded a web player demo. It has a user interface to configure some of the parameters so that you can get an impression of what is possible to achieve with the package. The automatic day/night cycle is disabled in the demo, you just set the time of day with the upper most slider.
Version 1.2 just got released with a number of fixes and new features. It is now possible to adjust the sunlight falloff at sunrise and sunset. The cloud system has been greatly improved with a nicer overall look and parameters to adjust cloud color (dark or light clouds), coverage density and cloud shape to your liking.
Version 1.2 Changelog:
Fixed some bugs regarding linear vs. gamma space rendering
Fixed some issues with the horizon fadeout
Adjusted sun and moon size
Optimized sun and fog color calculation
Greatly improved visual quality of the cloud system
Added parameter to control cloud tone, allowing for dark clouds
Added improved stars texture at night
Added parameter to control the sun color falloff speed
One problem is that the game camera will always show a smaller part than the human field of view, but overall the sky is way to red. I’ve seen similar problems with the “silverlining” clouds sky package that will always show a red horizon in winter at this latitude (actually this is correct because of missing haze) but this won’t be such a huge problem when the terrain has some slight hills.
Beside the need of fixing the red sky, will you later add date, latitude and longitude to your package?
I also would like to see a webplayer without any trees and hills to see more of the clouds and horizon before I can think of buying.
First of all, about the red sky: V1.2 added a parameter to configure the sunlight falloff, if you set his parameter very low (e.g. 0.1) you can completely remove the red stage of the sunset/sunrise. I forgot to add this to the webplayer before, but you can test it in the new one I just uploaded. If you have any other questions or suggestions regarding the scattering calculation feel free to post them.
About the performance on iOS: I only have a third generation iPad (the first one with a retina display) and it handles it really well (reaching the 30 FPS cap in my test). The second generation iPad tends to have a better performance than the third generation (because it only has to fill 1/4 of the pixels), so it should work even better there. I cannot say anything about the first generation iPad however because I never got the chance to run the package on one.
Date, longitude and latitude are actually already in there. However, for the time being only date and latitude influence the sun’s position. I can of course also add the calculation for longitude if this is a thing a lot of people would like to see, so far I just assumed this is nothing too many people would need.
Last but not least I added a second web player demo scene that consists of 4 cubes and the sky dome. You can choose the scene you want to load, so the web player link did not change.
Thanks again for your replies, please continue to post anything you would like to see changed or added.
EDIT: If the web player does not ask you what scene to load, just refresh the page. The old one might still be in your cache.
The package does actually work with Unity 3.x, but I submitted it to the Asset Store with 4.x and apparently they limit the usage to 4.x because of that. I just tried to export it as a package in 4.x and import it into 3.x but it looks like the asset export format is incompatible between major releases of Unity. I’ll look what I can do to submit the next update with 3.x so that you can download it properly.
Speaking of the next update, please do send me all feature requests via personal message, email or a post in this thread so that I can prioritize the things you guys want to see in my development schedule. So far the ideas for 1.3 are to add an optional lens flare effect (this is a little hard as most lens flares look incredibly unrealistic and I’m trying to create a realistically looking one) and some sort of automatic weather manager (which may include rain and snow particle effects).
The problem with sky domes (spheres…) is the clipping distance view when the skydome has to be very large ( in a big scenery, terrain…), because, in order to “see” the whole sky without clipping artifacts you have to use necessarily a very large far clipping distance (adding draw calls) or use a second camera, adding complexity to the scene.
Thanks for working on getting this in Unity 3, plz. If this is a hassle, I may end up upgrading to Unity 4. I’m still very much on the fence, though.
I agree that a 2nd camera is a good thing, it keeps my main camera from having a huge draw distance.
You can adjust the sky dome such that it is exactly as big as your clipping distance. The sky dome won’t change its appearence just because you scale it up or down, I made sure of that. You are of course free to use two cameras, but my package is not limited by your clipping plane in any way because you can just adjust the sky dome scale according to your project’s settings.
While the package should run on Android I personally don’t develop for it. I do own one of the free Unity Android 3.x licenses they gave away ahead of the 4.x announcement, but I have never used it. If there’s an issue I will look into it, but I cannot provide any Android examples for now as I focus on Desktop and iOS development.
I’ll look what I can do in 1.3 regarding these things. What I probably won’t do is to calculate the sun and moon position based on the exact real-life date because it will just add a huge overhead for an effect that barely anyone will ever notice. I also don’t want it to become too earth-specific as the package should be applicable to all sorts of planets as good as possible.
Speaking of 1.3, I might look into completing the height parameter that will allow the sky dome to adjust according to the viewer’s height in the world. The basis for this is already implemented but there are some things left to do and it would allow the sky dome to be used in flight simulator games, given that you use it together with a volumetric cloud system.
Time for a quick development update: I locked myself into my coding cave and sat down to optimize the package performance for mobile.
I benchmarked the absolute worst-case scenario that the complete sky dome has to be rendered (no occlusions by other objects). If for example half the sky dome is occluded by other objects, the frame rate will double.
Before the optimizations:
iPhone 4 / iPad 1: 10-15 FPS
iPhone 5 / iPad 3: 30-40 FPS
After the optimizations:
iPhone 4 / iPad 1: 40+ FPS (EDIT: after some further optimizations I am now at 60 FPS on the iPhone 4)
iPhone 5 / iPad 3: 60+ FPS (iOS does not render frame rates above 60)
This was mainly achieved without any visual loss in quality. I did however implement a mobile version of the cloud shader with two changes compared to the desktop version: the “Cloud Sharpness” and “Cloud Shading” parameters are being ignored. This is because these parameters have to be applied per-pixel, which would cost 10+ FPS on the iPhone 4 and iPad 1. Newer generations are able to do these calculations while still reaching the frame rate cap of 60, so you might be able to use the desktop version of the cloud shader there. You can also achieve the same effect the “Cloud Sharpness” parameter has by just editing the cloud noise texture manually. I might add different versions of this texture to the package if this is something people would like to see.
Completely disabling the cloud layer also greatly improves the frame rate, so if you don’t need any clouds you could probably also get 60 FPS on the iPhone 4 and iPad 1.
In other news, the downgrade of the project from 4.x to 3.x is a little bothersome, but I will try to get this done some time this week. All that and an improved implementation for latitude / longitude are planned to be released in a few weeks or even days, so stay tuned.
The project is now on Unity 3.5 so the next update should make the package available for download for 3.x users
After some further work on the shaders I now have 50-60 FPS on my iPhone 4
I added a realistic sun lens flare effect and an additional parameter for how much the sky color is being influenced by the sunlight and therefore the sun angle, resulting in some pretty neat new sunset configurations - a few examples with different parameters:
