SilverLining for Unity: 3D volumetric clouds, sim-quality procedural skies [DEPRECATED]

We did update to Unity 4.0 internally. The Asset Store automatically requires the version (or higher) that the asset was built with.

However, there is nothing Unity 4.0-specific in the code that I'm aware of. Send me a note at fkane@sundog-soft.com if you're an existing customer and you want to update - I can just send you the package file to try out.

 

I purchased SliverLining last week and am very pleased with it, and also with sundog's support. Frank did some customization work for my particular needs, and he was extremely fast and responsive. Furthermore, with his help and tips, we've got gorgeous clouds and lighting effects with very low performance impact.

 

I second that! Always really quick replies.

 

Hi Sundog,

Just finished reading through all the material I could find on SilverLining, and it's looking mighty good so far!

One thing I thought I'd check, would this package work with stereoscopic camera setups such as the one for the Oculus Rift? I'm working on an architectural viewer that would really benefit from a realistic day/night cycle, but it needs to also work in VR. Standard Unity skyboxes for example do not work, does this use a skysphere/custom skybox?

Thanks!

 

I can't say for sure, as I don't have an Oculus Rift. But, what I can tell you:

- SilverLining for Unity renders its own sphere for the sky.
- It assumes the sky and clouds are positioned relative to the Camera.main position.

At any rate, since we don't use Unity skyboxes at all, I would think you'd at least have the ability to address any issues by modifying our scripts if necessary.

Hope this helps!

 

The main issue I've encountered with the Rift so far is that most effects don't take into consideration the sideways roll of the camera, which is something you do not get in 'normal' games with standard camera controls. Anything using billboards will apear to spin with the camera when you tilt your head, due to the fact that orientation is does not match cameras. This is easily solved in most cases by adding an observer field to the effect which sets rotation based on one of the Rift cameras.

I think I'm about ready to give this a go! Especially excited that the Hosek-Wilkie made it in to the Unity version.

 

So I bought the package, and after some initial experiments I cannot manage to get the clouds to display on the Oculus cams. This is what I get:

 

I'm flying blind here, but I noticed your "MainCamera" is disabled while the two "OVR Camera Controller" cameras seem to be the ones that matter. SilverLining relies on the position of Camera.Main for positioning the clouds. Is it possible to mark one of the OVR cameras with a "MainCamera" tag? That might clear it up.

 

I've tried having one of the cameras tagged as MainCamera, as well as tagging them both. Have set clear flags to Depth only on both cams. Still can't get the cloud or star layers to show.

Here's a shot of my settings for the right camera:

 

The forum seems to have eaten your attachment!

One other thing to check is the far clip distance on the cameras. The stars are 90km away, and the clouds are probably around 30km from the viewpoint. Normally SilverLining automatically sets the far clip on Camera.main to 100,000, but perhaps something about the Oculus cameras is preventing or overwriting this setting.

 

Great success! This was exactly it. The Oculus camera controller was setting the far clip distance to 1000 for both cams on run. I can now see stars and clouds!

I have to say the sky looks really excellent, some of the best atmospherics I've seen at different times of day and night, and in VR it looks really stunning. The way the light plays on the clouds is miles ahead of anything else I've had the pleasure of using.

Now, the billboard rotation effect is there, and quite distracting especially in VR. It is only fully apparent when looking upwards and rotating the view, where all the cloud billboards rotate around with the player. In VR you can see it quite clearly if you roll your head while looking straight ahead also. Can we match the rotations somehow?

 

Glad we found it!

As for the billboard rotation - the cloud puffs are just Unity particles, so we don't have a lot of control over that effect. Changing the particle rotation at runtime from a script doesn't seem to work any longer in Unity 4.0, so even if we could come up with some way off manually setting the particle rotations there doesn't seem to be a way to apply it.

The only solution I can think of is to replace our use of Unity particles with a built-from-scratch particle system that blends the billboard alignment axis toward the horizontal as you start looking upward (this is what the C++ version of SilverLining does.) But, I doubt you'd be able to duplicate the performance of Unity's built-in native particle systems, so you'd end up trading one problem for another after a ton of work.

Sorry I don't have a solution here - if anyone else has ideas on how to get Unity particles aligned consistently with an Oculus Rift do chime in.

 

Hi,

I'm looking for a asset like thisone. I tried the demo but is was very slow. Is that because of my computer or is it a heavy script? Does anyone has experience with that?
I also didn't see the sunshadows, do they work icw this asset?

 

The scene in the demo is pretty heavy, so that's part of the performance burden. The clouds themselves are Unity particles and we've highly optimized our use of them. All of our customers, to my knowledge, are satisfied with the performance - but you can always make your own tradeoffs between performance and visual quality by adjusting the size of the cloud layer and its density. The number of particles will increase with the square of the cloud layer dimensions, so it is best practice to only use as large of a cloud layer as you need.

SilverLining does provide a directional light source from the sun that acts like any other directional light source. I don't think we enabled shadows in the demo, but you could (assuming you have Pro). Note however that you can't get shadows from the cumulus clouds; Unity cannot cast shadows from transparent particles.

 

Hi Frank,
Is there a recommended way to have clouds within a small region? If i set my cumulus dimensions to 8k x 700 x 8k i get no clouds. I've got the silverlining sky and prefab at 0,0,0 and the cumulus position at 0, 1000, 0 but if i increase the cumulus dimensions to get some clouds, they are all at z > 25k. My scaling is set to 10k, 10k, 10k of the _SilverLiningSky, so the sky dome doesn't intersect the terrain and break differed rendering.

I'd like the clouds to be focused around the centre of the 8k x 8k region.

 

Change density.

 

Any chance of introducing volumetric rendering for clouds instead of particles so they look great even when rotating right next to a cloud? ( same question for the non unity version of silverlining in case the answers differ)

 

Hi Loki,

Here's a screenshot where I tried to recreate the setup you described. Not sure what we're doing differently (could be the density as VIC20 suggests.) My camera is at 0,0,0 with an X rotation of 340 to look up a bit - perhaps comparing my settings to yours will help.



Bear in mind cumulus clouds can be as large as 5km across, so an 8km area is cutting it a little close at lower densities.

 

The non-Unity version of SilverLining already supports this. The stratocumulus clouds use GPU ray-casting; you can find some images of them in our SilverLining image gallery.

3D textures at this size get really expensive really fast, however. I haven't yet tried doing this in Unity, although I see it does support 3D textures so in principle this should be possible. I would just be concerned about the performance hit.

I know at least one customer has purchased the native C++ version of SilverLining and wrapped it with a native plugin for Unity in order to get these more advanced effects. Our C++ version also implements its own particle system, which solves the rotation problems you describe.

I think it's more likely that you'll see an update to SilverLining for Unity that replaces our use of Unity particle systems with our own billboard implementation. I think that would both look and perform better, and handle particle rotation the way we want.

 

Thanks Frank, i'll give it a go tomorrow, a few of your settings look very different to mine.

 

Is there a standalone (non unity) demo where i can see the volumetric clouds in action?
How much work would it be to port that additional feature to unity?
How much work would it be to integrated (with or without source code license depending on if required) silverlining with a third party engine?

 

Yes, if you download the Sundog Demo application from http://sundog-soft.com/sds/evaluate/demos/ and hit the little eye icon, you'll enter "interactive mode" where you can create different kinds of clouds on your own. Stratocumulus clouds use GPU ray casting.

Technically, our particle-based clouds are still volumetric, they just use "splatting" instead of ray casting. I personally prefer splatting to ray casting; it gives you more detail, and at much lower cost.

I can only guess; probably on the order of 30 hours assuming Unity's API's gives us what we need. Again, if the objective is to solve the particle rotation issues, I think the time would be better spent replacing the use of Unity's particle systems with billboards. With 3D textures, you'll be very limited in the size of the cloud layers you can create due to how quickly the memory requirements blow up.

Depends on the engine of course. If it's a home-grown engine written in C++, I've seen people get up and running with just a few hours. Deeper integrations take longer. For some comparisons, I think we spent about a week apiece on OpenSceneGraph and Ogre integration, a month on Havok Vision, and around 3 weeks for the initial Unity integration (all of those were part time efforts). It's really to Unity's credit that it only took that long, as we had to re-implement everything in C# and using Unity's particle engine for that.

 

Thanks for all the info.
The issue with particles is (unless i'm getting it wrong) it's always going to look bad when you're up close rotating (even with billboards), i'd like to have good looks both far away (looking at the sky from the ground) and close (at the top of a mountain as high as the clouds).
Currently the clouds look good even from up close / inside, except if you start rotating on yourself when you're next to them.

 

There are techniques for keeping billboards oriented consistently even when you're rotating, or looking straight up. If you play around with the demo of our native libraries and look around near the clouds, you should see the difference.

Basically they are axis-aligned with the world's up vector, and we smoothly blend that up vector toward a tangent vector as the camera starts looking up. Unity unfortunately doesn't give you any way to modify how particles are aligned, even when using your own shaders.

 

My game is set at 5,000m elevation, where the sky is a deeper blue than at sea level. I've set the Altitude variable in SL accordingly, but it doesn't change the sky color. Is there any way to tweak that?

 

It does seem that the isothermal effect doesn't work as well with the Hosek-Wilkie sky model as it did with the Preetham model.

I think the most straightforward workaround would be to adjust the gamma correction, to get the richer sky colors you're after with that elevation. You'll find this on line 47 of SilverLiningSky.cs:

public float oneOverGamma = 0.45f;

Try increasing it to, say, 0.7f.

Frank Kane
Founder CEO
Sundog Software LLC

 

That did the trick, thanks!

 

Hi,
I want to use Silverlining in a UAV simulator Project and have some questions:

1) Silverlining uses Unity3D particle system to generate clouds but it use Soft Particles?
We really can't have some sliced cloud planes in our air-plane like the left image:


2) We are able to use Deferred Rendering with Sunlining?

Best regards

 

Thanks for having a look!

Our particle shaders are based on Unity's built-in ones, and include their support for soft particles. You'll find a soft particle factor slider in the _SilverLiningPrefab's CumulusCloudPrefabLegacy object that may be used to tune the effect.

SilverLining has no known issues with deferred rendering.

 

I want to adjust the nighttime ambient light -- make it not quite pitch dark. Where/how can I do that?

 

If you crack open the src/SilverLiningSky.cs script, look for the lightPollution public member. By default, it's set to zero.

It's units are watts per square meter, so you'll probably want to set this to a small but positive value.

 

Perfect, thanks!

 

Hi,

I was wondering if and when additional releases to Silverlining for Unity are planned. I would be especially interested in some possible features mentioned in this thread, namely

- additional cloud types
- replace particles by custom billboards and/or raycasted clouds

 

In all honesty, updates depend mostly on when I find myself with a few extra hours in between contract jobs. So I don't have a schedule I can give you. Doing something to add precipitation effects was next on my list, as it is the most requested feature.

I'm not sure custom billboards will perform as well as Unity particles, which is why I've shied away from them. It's something we could test though. One thing we could do is offer a "Pro" version of SilverLining that is a wrapped native plugin using our C++ SDK product, which does have custom billboards and ray-casted clouds (as well as precipitation) - but it would only work with Unity Pro and on desktop platforms.

What additional cloud types do you need?

 

I would especially be interested in cumolonimbus and cirrocumulus clouds.

A (more expensive) Pro version would be great, but why would it only work on desktop? Granted, there are some cloud types that might kill the performance on mobile, but shouldn't the current feature set work with the Pro version on mobile?

 

It would only work on desktop because we don't (yet) have a native iOS version of the SilverLining SDK.

 

Hi Frank,

is it possible to only use the moving clouds without the sky? I use Skyshop for HDR Lighting and for the background skybox. All I really need is this static background and convincing moving clouds.
Also can I manually tune the lighting of the clouds so that it would match my custom background? And do I have manual control over how fast the clouds move?

Last question: How high do I have to set my main camera's far clipping plane in order to render the clouds + the sky? I'm concerned I'll have to set them to insanely high values and thereby maybe introduce depth resolution artefacts with SSAO and shadows.

Thanks!

 

Hi Sean,

Yes, if you disable the mesh renderer on the SilverLiningSky object, our sky dome won't be rendered but the clouds will.

The lighting of the clouds is automatic and based on the time of day, date, and location you are simulating. There are also scaling parameters on the sun and moon light so you can adjust the overall brightness of the cloud lighting manually.

The motion of the clouds is determined by a wind velocity that you can set to any speed and direction you wish.

The far clipping plane will determine how far out you can see the clouds - the farther, the more convincing the scene will be. Generally speaking you'll want to be at 50 km for reasonable looking results. There is a parameter for scaling the clouds, so you could perhaps play games with shrinking the clouds and bringing them in closer if your game is ground-based.

 

Thanks Frank.

I got the chance to play around with SilverLining at university for a while. The visual quality is very good, but I don't think this plugin is suited for my needs.

What I miss is manual artistic control over the single components. Everything seems very tightly interweaved to ensure physical plausibility. Say for instance I'd like to have my own sun. You can't assign a custom one, you have to use the SilverLining sun. When you try take this sun out of the equation either by disabling it in the inspector or by setting "Sun Light Scale" to 0, the sky turns into a boring baby blue. Even the faint clouds (can't recall the name) at the hightest altitude disappear. Why is that so? The cumulus clouds seems to remain unaffected as well as the overall sky color.

It would also be great to change the color of the sun, not only the intensity.

What annoys me most is that I can't change the ambient lighting in the scene which is extremely prominent and flattens the shading in the entire scene. SilverLining has it completely under control and only let's one change the intensity with the "Ambient Light Scale" parameter. Then however the cumulus clouds turn dark and to a lesser extent the clouds in higher altitudes as well. As I said, everything is tightly interweaved. That might all be physically plausible, but it severely limits artistic freedom. I would advocate extending SilverLining to more fields of application than just purely physically correct simulations or visualization. That's not where the average Unity user comes from.

Last but not least I found that SilverLining caused some really weird shading on my terrain as well as my buildings while I am in scene view. I attached some cropped screenshots which always show the particular part of the scene with and without SilverLining.
I am not sure how much of that shading is carried over into game play (not much it seems), but the odd shading in the scene view alone is really annoying as I can't properly paint my terrain like that. I can't really judge anymore how much of a certain terrain texture is currently assigned to a particular terrain patch. Do you know where this shading problem stems from? At first I though it was ambient light still being active somewhere, but that doesn't explain the bumpy specular shading on the buildings.

So yeah, all in all it would be great to allow more manual control over the single components. At least an option to modify the lighting without affecting the sky and the clouds.

If you know any workarounds for my aforementionend problems, I'd really appreciate your help.
I also apologize in advance if I criticized something erroneously, maybe in case I oversaw something very obvious or wrote something else stupid ;-)

Sean

 

Sean, thanks for your feedback. It sounds like you are trying to accomplish a couple of different things:

1. Using your own light sources for your scene, while letting SilverLining just light the clouds. You can do this by unchecking the "SilverLiningSunLight" and "SilverLiningMoonLight" objects in the inspector, and adding in your own directional light to replace them. I think the difference in shading you see with and without SilverLining is just due to our particular ambient, diffuse, and specular light values, which are high during daylight. But you can disable our light sources and substitute your own.

2. Using your own sun texture. You're right that you can't disable the SilverLiningSun object without breaking the sky, but you can disable the particle emitter underneath it.

At a high level, we did design SilverLining to be an easy way to add highly realistic dynamic skies and weather to a scene just based on a given time, location, and conditions. To keep it simple we minimized the controls. Based on your feedback, it sounds like it would be useful to be able to totally decouple SilverLining's lights from the clouds and let you specify explicit light sources of your own that illuminate not just your scene but also the cumulus clouds as well. We'll certainly consider that for a future release - wouldn't be too hard.

 

When I disable the objects "SilverLiningSunLight" and "SilverLiningMoonLight" in the inspector I get hundreds of copies of this error message in the console at runtime:

NullReferenceException
UnityEngine.GameObject.GetComponent[Transform] () (at C:/BuildAgent/work/ea95e74f6e5f192d/Runtime/ExportGenerated/Editor/UnityEngineGameObject.cs:27)
SilverLiningSky.UpdateLight () (at Assets/SilverLining/Src/SilverLiningSky.cs:562)
SilverLiningSky.Update (.SilverLiningTime time, .SilverLiningLocation loc, UnityEngine.Renderer renderer, Boolean bIsOvercast, Boolean doFog) (at Assets/SilverLining/Src/SilverLiningSky.cs:282)
SilverLining.Update () (at Assets/SilverLining/Resources/SilverLining.cs:118)

Also no cumulus clouds are rendered.


It turned out that the odd shading was largely caused by the Moonlight. However, the SunLight still causes quite a mess with the shading. I tried disabling the "SilverLiningPrefab" object while I wanted to work on the terrain, but that didn't change the lighting at all. Does Unity sometimes cache things behind the scenes for a while?

I perfectly understand your reasoning behind this design. But nonetheless I find an extra layer of control a good thing. In SilverLining I'd suggest to offer the user the posibility to decouple components and tune them individually. I guess a situation where everything looks nice except one or two minor details often arises and then it's immensely frustrating to be locked to a hardcoded simulation.

You could hide such additional controls in an advanced rollout in order to keep things easier for the novice user.

Btw, it would also be great to have a documentation even when, for the most part, parameters are self explanatory (but not all!).

 

Ah, I was disabling the SilverLiningSunLight / MoonLight at runtime which seems to work - but isn't terribly helpful in the end. As a workaround, you could just set the intensity of the underlying Light components to 0.

 

:-D I could have conceived of that solution, too ;-) Stupid me. Instead I went into the script and replaced the line
light.enabled = light.color.g > epsilon;
with light.enabled = false;

Btw, I also put comments on line 595 in the SilverLiningSky script
RenderSettings.ambientLight = skyLight * ambientLightScale;

so that I can set the global ambient color manually. Could this small modification cause issues somewhere later on?

Thanks!

 

Those modifications are both perfectly reasonable things to do. Thanks for diving under the hood there.

 

This I would love to see!

 

My game is going to have a few alien looking worlds: green suns, multiple moons, strange weather, etc. Would this plugin be useful in my situation, or is it mostly geared towards looking like a realistic Earth?

 

In all honesty, it's geared toward looking like a realistic Earth. It might be a useful building block if you need volumetric clouds and you're willing to dive into the scripts to shoehorn your own alien light sources into it, however. The dynamic sky would be a little trickier - you'd have to mess with the chemical and particulate makeup of the simulated atmosphere to get different colors out of it. If you're comfortable with C# you might be able to get what you need, but I'll admit there are likely simpler approaches to producing alien skies.

 

Thanks for the honest answer! I appreciate it.

 

Hello! This is an amazing package!
I'm trying to integrate it with oculus too (someone also did it a few pages back)
It works almost 100% out of the box.

I'm having a problem though... The left oculus camera only works if I click and select the oculus prefab while playing (the oculus prefab contains both cameras). Otherwise I only get the right camera image... When I hit play and click the oculus prefab everything is great... And I can edit my scene. Problem is: When it's fullscreen I cannot stop to be clicking, and I tried to build and run and the problem still there... Cannot select it on the final app, so hahaha


Any suggestion?

PS: My field of view is already set to 100000, I'm on macos 10.6.8 using unity pro 4.2, and both the individual cameras and the oculus prefab are set as main.

 

Thanks for using SilverLining, Jessicajrs!

I don't have an Oculus Rift, so it's hard for me to say what might be wrong. It seems really weird that just clicking on the Oculus prefab in the editor would change anything. I think you already found the discussion back on pages 3-4 of this thread where "Metakid" ended up getting it working. The keys were tagging one of the cameras as "MainCamera", and ensuring the far clip on both was set to 100km. But, it sounds like you're already doing that.

(You said you set the field of view to 100000 - I assume you meant the far clip distance! Definitely make sure that the far clip setting isn't getting overwritten at runtime somehow.)

SilverLining makes some references to Camera.main internally, and I think it's somewhat ambiguous as to which camera it picks up if you have multiple cameras tagged as MainCamera. I would choose one, which represents the current eye point - left or right shouldn't really matter.

I'd suggest perhaps messaging Metakid to see if you can figure out what he's doing that you're not. Failing that, feel free to send a copy of your project to support@sundog-soft.com and we can at least see if anything stands out to us.