SkyX plugin [SkyX 0.1 released! - Page 1]

[Xavyiy]

@steven
Seems that your graphic card pronunces more the layers than mine (maybe the contrast, or something like that..), anyway I've to work on the properly layers proportion depending of the camera position, so.. don't worry about that
Maybe with a bigger window resolution the visual artifact is minimized

About fps, it's all gpu dependent, the cpu work is insignificant(just look to the floor and the frame rate must be 200/300), it seems that older cards are not very fast with 3D textures, or just that in the demo the camera is so close to geometry slices!

Xavi

[steven]

Tried with higher resolutions but it didn't help.
And looking at the "terrain" will only add ~10 fps.

We will see with the final version

[stealth977]

@Xavyiy:

FYI, i am getting 48 FPS and no visible artifacts with Ati Mobility Radeon 3470 at 1280x800 resolution....

ismail,

[_tommo_]

No artifacts and 58 FPS on my Nvidia 8600 GT
Relly cool, even better than in the video!

The only thing that looks not so realistic is that the clouds are all in the same layer... i mean, you don't get "high" clouds, vertical clouds etc, all the clouds have a "flat" side up and down, and are all at the same altitude.

[xadhoom]

I get around 50+ on a GF 7950 GX2 station. Hopefully there is still some space for increasing computational efficiency (paging?)... The clouds look good at some distance but especially directly above the viewpoint they look much to blurry! The eye always looks for gradients and edges to figure out the shape and most types of clouds have visible edges in real world.

Good work, though!

[Kencho]

Some zig-zagging artifacts here (probably caused by a low tessellation of the volume shells) Anyways, around 35 FPS here (GeForce 8600M GT)

The demo is beautiful. Took the freedom of trying a noise map I did a couple weeks ago for a Caelum demo. Adjusted the noise scale to 6 instead of 2 in the shader and the clouds got much more texture I would love to know how you format the noise maps so I could fine-tune it a little more. Anyways, hope you find it useful

More cloud-like noise texture

CloudNoise1.png (146.77 KiB) Viewed 8552 times

I've assumed there are three noises added through each different channel (one noise for the red, one for the green and one for the blue). If you extract a single channel and convert it to grayscale you'll get the original noise map, in case you want to do your own map

[Karan]

I've got an 8600M GT too and I get around 100 FPS (800x600) and no artifacts. 45 FPS with 1280x800.

[Obscurity]

Very nice plugin, beutiful and realistically looking (for what is currently implemented).

Strange that so many of you seemed to get such low fps, do you use vsync? Without it I get an avarage of ~110 and worse ~85 @ 1680x1050 with 8xAA with about a min of running time and some looking around. I got a 8800gt 512 MB... and no artifacts here either

[Xavyiy]

@Kencho
Thanks a lot for the noise texture!
About the noise format, just a texture where each channel represents the xyz distortion [(value-0.5)*2, like normal maps], to be honest the noise textures I've used came from google
Do you use PS to make the texture, or any especific texture generator program?
It'll be very useful the same noise texture(same pattern) but with a bigger resolution(like 1024x1024)!
About the zig-zaggind artifacts, yes, it's because of the low tessellation, I'll solve it in a future(It's just a minnor visual artifact)

@_tommo_
Yes.. I've to work on better clouds generation, it's on my todo list

@xadhoom
About the efficiency, the problem is in the GPU, the CPU charge is insignificant(even clouds geometry are updated by frame, there're not too many polygons), but I'll work on minimize the batch count that maybe helps the gpu problem

@Obscurity
Thanks
About the frame rate, I think that new GPU's must obtain decent(100+) averages, anyway I'll try to obtain better frame rates in old cards!

[Praetor]

About noise textures: I use them a lot for natural scenes. I use photoshop to make all of them. The trick I often use is after the clouds filter I use the levels control to adjust the falloff and "sharpness" of the noise. Also, don't forget that you can generate the clouds at different resolutions and then upscale or downscale to the right size. It'll give different "scales" of noise. Also, combining several different noise textures generated in this way in the three channels of your final image gives more variation to the noise, since each channel has a different pattern.

[Vectrex]

No artifacts and 58 FPS on my Nvidia 8600 GT
Relly cool, even better than in the video!

The only thing that looks not so realistic is that the clouds are all in the same layer... i mean, you don't get "high" clouds, vertical clouds etc, all the clouds have a "flat" side up and down, and are all at the same altitude.

Well you'd just use simplified upper cloud layers. Ideally this could be added to caelum which you could then use for it's clouds, as the simplied layers, with skyx for close ups. This is what simuweather does

[ImpScary]

I'm getting around 250 FPS with GF9800 GTX+ 1680x1050 full screen, but it freezes for a split second every 10 seconds or so. It also happens with low resolutions and in windowed mode as well.

[Kencho]

Forgot to mention I was using a res of 1440x900. The gfx card is an integrated one (laptop), so don't count with a good fillrate (that's probably why overlapping many shells kill the performance).

The noise texture was done in PS the way Praetor described, though I iterated the difference clouds a few times to give the base noise that organic, smokey look. Also, prefer to use the curves adjustment instead of just the levels as I get more control on the intermediate levels, but that's just a personal preference

By the way, have you considered moving the texture coordinates calculation (you asked about it in another thread) to the vertex shader? You have all the tools there, and definitely will find speed improvements by doing so. As you're requiring vertex shaders support nonetheless, moving the calculations to the GPU shouldn't be an inconvenience for the user (I guess)

[Obscurity]

I'm getting around 250 FPS with GF9800 GTX+ 1680x1050 full screen, but it freezes for a split second every 10 seconds or so. It also happens with low resolutions and in windowed mode as well.

Yeah, I forgot to mention, I get this "stuttering" every 10 secs too, it's what dragged my worst fps to 85, in the in-between period the fps never dropped below 110. Without the stutteringthe avarage fps would probably be ~150, since that's what i get for long periods if I look at the real-time fps. It's hardly noticable, and I'm sure it's driver related since I've get it in some fallout 3 sessions too... but not in every 3d app or new 3d game(crysis fo instance) for that matter.

[DanielSefton]

Tested on an nVidia GeForce 6600 and got an average of 25 FPS at 800x600, and 10 FPS at 1280x1024. No visual artifacts as far as I can tell.

it's stuttering constantly for me (minor stuttering - it looks like everything is vibrating). But then there's also the major jerk every 10 secs like you guys mentioned.

I know my card is outdated, but I would never buy a high powered one for development, it's useful for performance optimisation.

[KungFooMasta]

I also get the periodic jutter on the 9800 GT. Clouds look good.

[Kencho]

Moar modding!

Okay, changed the way you apply the noise to something more "familiar" to me (it's based on the way I did the layered clouds prototype in Caelum). The noise now is a modifier to the final alpha. I've added a new parameter "uNoiseInfluence" that adds the noise with some particularities. In a nutshell, it's now applied only to the "grey areas" of the clouds' alpha.

Here are the modded files:

SkyX_materials.rar

Modded material

(1.34 KiB) Downloaded 361 times

SkyX_VolClouds_shaders.rar

Modded shader

(1.01 KiB) Downloaded 273 times

Also enlarged the noise texture as you asked. The texture is now grayscale because of the way it's applied.

Higher-res noise texture

CloudNoise1.png (492.11 KiB) Viewed 8411 times

Hope you like it

[Xavyiy]

@Kencho
Cool!
The only reason for using this extrange kind of noise perturbation is just to get a little displaced cloud information(Stored in the 3D texture: Light absorcion factor, etc..), during these days I'm going to try some different approaches and select the best
Thanks for the texture!, I've played a little with PS and I've done some good looking noise textures hehe
About move the noise coords calculation to the vertex program, yes, is something I'll do, but before I'm going to work on fix the zig-zagging visual artefact(if posible with the current geometry!).
Now I'm thinking a little about the light scattering approach, but this is just playing some days

@All
The little freeze that happens each ten seconds is when the volumetric data is updated, so.. it's normal.
A lot of speed optimizations can be done in this context, so.. just waiting to future versions

Xavi

[Kencho]

Definitely waiting for the next versions

[Xavyiy]

Hope to have something more to show in some weeks!
I'm seriously thinking about separate the Volumetric cloud system from SkyX core and release it as a plugin, then just a VCloudsSkyXManager.cpp/h (Or equivalent) will be sufficient to combine any sky plugin(Caelum, skyx, ..), just passing the correct ambient/sun color values to the volumetric clouds plugin
I'll see it in a future, now it's time to rewrite all the volumetric data generation stuff!

Xavi

[compvis]

@Xavyiy : Nice demo ! I get 248 fps, 1440x900 on NVIDIA GeForce 9800 GTX/9800 GTX+

[Praetor]

I'll see it in a future, now it's time to rewrite all the volumetric data generation stuff!
Xavi

Threaded, or amortized over several frames perhaps? I think updating only a subset of the grid continuously will give you a smooth and jitter-free update. You could even get fancy and randomize the order you update the cells so the update doesn't introduce noticeable patterns.

[amigoface]

just to report
ati x1950pro
screen 1440 X 900
fps between 60 and 100

[sinbad]

Very nice! About 300fps on my 9800 GX2.

Your approach is quite similar to the one I used for Nimble. The hardest thing in my experience is getting from 'fluffy' cirrus and altocumulus/stratocumulus clouds, to the more hard-edged 'heavier' clouds like Cumulonimbus. Most cloud systems either do large banks of very low-resolution fluffy cloud, or very small clusters of discrete harder-edged clouds. The 'holy grail', which we were trying to do with Nimble, was the arbitrarily large, hard-edged cumulonimbus clouds - these are very tricky indeed, because anything with a hard edge makes artefacts much easier to spot, but I think you're headed in the same direction we were, which can give some good results.

I've stayed out of this thread mostly because I can't really talk about the work I did until the owners (now Linden Lab) choose to make it public

[Vectrex]

I've stayed out of this thread mostly because I can't really talk about the work I did until the owners (now Linden Lab) choose to make it public

But.. idea's can't be ndaed? Can they?.. Daddy??