SkyX plugin [SkyX 0.1 released! - Page 1]

[jacmoe]

It's a pity the name C++0x is already taken ...
Otherwise it would be a good name - maybe Cloud++0x ?
So, Sky++0x and Cloud++0x

[steven]

Using these blocks, it's very easy to move clouds depending of wind direction with smooth and pretty results,

Do you think it will be possible to have different winds directions at the same time?
Sometime you see low and high altitude clouds moving in different directions. Even two directions would be amazing.

If I were you I would write a technical article and publish it in a revue. Ask your uni profs for submission and referral.

[mikeInside]

Looking forward to this one!

Just wondering: if I wanted to simulate a planet with multiple suns/moons, and a red and purple sky, would skyX be flexible enough to accommodate me?

[Kencho]

Excellent work, mate You're getting awesome results.

Some info you might find useful:
The ever-present-in-these-discussions link to VTP: http://vterrain.org/Atmosphere/ , http://vterrain.org/Atmosphere/Clouds/ & http://vterrain.org/Atmosphere/rain.html
Lightnings at very high speed (useful to understand its mechanics): http://www.youtube.com/user/ztresearch

Keep up this awesome work (but don't fail the exam!).

[_tommo_]

*

Obviously i didn't think about it
You could still try an hybrid screen space method, rendering the perlin noise quads using a shader that blends the local depth with the rendered image... this way each quad still adds "some cloud" to the scene, and it would allow multiple layers of clouds, i think
But you should render the quads in depth order, farthest first.

[Xavyiy]

@Praetor
Thanks for your suggestion, one time I'll test the new geometry approach work as excepted, I'll adapt it to use instancing and getting the maximun performance!
@trilobite
2009
@ToeNails
---> <---
Of course 0.2 version will be backwards compatible with 0.1(maybe just some minor changes will be needed, but nothing difficult!)
About rain, turbulence, etc .. effects, I think If finally skyx volumetric cloud system works as I want, maybe I'll separate it from SkyX and make another plugin with these kind of effects(vol clouds, rain effects, turbulence, ..), because I'm sure a lot of people want to use Caelum as their sky system, or even just a simple skybox, and add clouds and atmospheric effects to their scenes , anyway.. Hydrax, SkyX and (maybe) the future clouds/atmospheric effects plugin will be totally complatible, and with open-source demos showing how to integrate them in the same program easely!
About multiple suns/moons, it's a little more complicate since shaders I use for light scattering are thought for one sunlight, anyway for multiple moons or planets around the skyx a simple billboard must be sufficient.
@steven
With the approach I'm going to use, is quite hard to have different winds directions at the same time. Maybe for offline rendering it'll be viable to do some(a lot of) modifications in order to get different winds depending of the altitude, but it's something not trivial to obtain with current geometry/data simulation approach!
@mikeInside
See @ToeNails for multiple suns/moons, and for red/purple sky, yes, it's possible, only you'll have to change red/green/blue wave lengths in SkyX::AtmosphereManager
@Kencho
Thanks!, I think th lightnings link it's going to be very useful to me
P.D.: I'll try to don't fail the exam !
@_tommo_
Anyway I think the screen-space method is not very useful for clouds, because even you can blend the local blend with the rendered image you'll get a pixel with only one colour with means only one position(even if the pixel is an interpolation between two depth's)
@jacmoe
LOL, Sky++0x, Cloud++0x = SC++0x

And thanks to the Ogre team for giving me the Ogre expert user badge!!

[syedhs]

And thanks to the Ogre team for giving me the Ogre expert user badge!!

Dude, you deserve it!

[vilgeits]

One of the best addons I ever seen to Ogre

[Xavyiy]

A little video showing the development of the new cloud geometry approach:
http://www.youtube.com/watch?v=YAOSqIUwqVg

[boyamer]

Why not release a demo?

[xadhoom]

A little video showing the development of the new cloud geometry approach:
http://www.youtube.com/watch?v=YAOSqIUwqVg

Maybe a short word about what we see on the video would improve understanding

[jacmoe]

What you see is the underlying magic, without any materials.

[Kencho]

Yes, I distinguish three meshes: The sky dome, the terrain mesh, and a set of shells used to render the clouds' volume texture if I'm right. Did I won the gallifantes?

[xadhoom]

Yeah that was the easy part I could figure out, too. But why do these polygons move in line towards the center etc. Maybe i have to read the underlying paper to get an idea of the concept...

xad

[Xavyiy]

Hi!
@xadhoom
There isn't any paper for the rendering approach I'm using (Only particle-based papers, but I don't like so much this approach..), the slices moves because of clouds will move too, for example, if you're looking opposite to the wind direction, you'll see the clouds moving from the horizont to you, and.. if slices are static, the volumetric texture is going to pass trough these slices, but the displacement effect is not going to be correct, you need to move the slices in the wind direction.
For example, if the angle between camera direction and wind direction is 90º, the slices must be static, and the volume texture is going to pass parallel inside the slices...
This is the basic idea, and if I'm not wrong is a very similar approach that Simul Cloud software guys uses in their weather SDK

@Kencho
Yeah, there're exactly these 3 meshes

@xadhoom
I'll post tonight or tomorrow some technique information about the rendering approach

Xavi

[Kencho]

Ahh... got it. I was curious also about why the shells are moving, but now I think you want to avoid the "popping" artifact often seen in volume textures rendering (specially if the distance between the shells and the camera is constant and the camera moves around). Nice one

[Xavyiy]

Yes Kencho, the aim of moving the shells is to avoid this classical visual artifact . And.. now I can say that it works better than expected!

I request some help for this problem: http://www.ogre3d.org/forums/viewtopic.php?f=2&t=50740(It's driving me crazy..!), and.. after solve it I'm going to record a little video of the clouds
About frame rate, it's about 60 at the moment (Nvidia 8600gt): Terrain+Terrain light scattering+Sky+Volumetric clouds.

Xavi

[Xavyiy]

Well, now that the projection problem is solved, it's time to show a little video!
Here's the youtube link:
http://www.youtube.com/watch?v=533OluRUQrM (Watch in HD!)

As you can see, there is a lot of work to do related to cloud light scattering, but.. the system seems to work as expected!
Hope you like it!

Xavi

[DanielSefton]

It actually looks real!

Is that the new algorithm? And, the screenshots were the old one?

[Kencho]

Woah! Impressive work Xavyiy Can't wait to see it finished

[Xavyiy]

@Kencho
Thanks !

@DanielSefton
Yes, this video shows how the new geometry approach works!
Older screenshots where taken with the old argorithm, maybe old screenshots visual quality seem similar to the new video, but this is because them are just screenshots.. in movement the effect was horrible...! (And the frame rate, worst than horrible..)

If someone is interested, here is the direct link to the video:
http://modclub.rigsofrods.com/xavi/SkyX ... CLouds.wmv [WMA, 1280x800 - 13.2Mb]

Xavi

[jacmoe]

That's some serious good looking clouds!
I guess this can do local fog as well?
I am thinking about dungeons..

[boyamer]

Can't wait to try it out

[Xavyiy]

Hi all!
I've decided to release a little demo application, just showing how the volumetric system works
You have to know that it's still in an early development stage, there're a lot of bugs to fix and things to change (Like light scattering, optimizations, etc..)!

Demo download link: http://modclub.rigsofrods.com/xavi/SkyX ... dsDemo.rar [4.8Mb]
Demo youtube video: http://www.youtube.com/watch?v=F_feXn80H7c
Direct video link: http://modclub.rigsofrods.com/xavi/SkyX ... louds2.wmv [1280x800 - 7.2Mb]

Xavi

[steven]

Nice

ATI x300 = 18 fps windowed

As you can see there are very visible "layers".
In movement they really catch the eye.
They are more pronounced when you look at the apex.