making skies like this :

monkeycracks · Post by **monkeycracks** » Mon Jul 16, 2007 2:23 pm

http://home.earthlink.net/~tanstaafl/morrowind010.jpg

It doesn't look like they have a skybox, and if they do they don't have the sides or bottom unless the sides and bottom are the same color as the fog.. but the fog changes color quite a bit in that game. (Morrowind).

Anyone having any luck pulling off really nice sky+fog effects? If so would you mind sharing your knowledge =)

JP · Post by JP » Mon Jul 16, 2007 2:51 pm

I wonder if you could render that much like rendering just the top of the skybox (so just a quad without depth testing) and then apply fog to it depending on how far away it is from the camera and then you'd get the fog coming down the sides. Might need a nifty bit of math to get it looking like that though.

The skies in God of War 2 are amazing imo. I just look at them and try to imagine how they'd be rendered and can't really see it! You can see the skies a little bit in this video at 1:45 when you're flying on Pegasus but i think that's an early version of the game so the skies are a bit different.

bitplane · Post by **bitplane** » Mon Jul 16, 2007 2:53 pm

here's an idea-
make a transparent sky dome, scale it up larger than the fog, then move it down so the top is visible. draw a nice cloud cover texture, and have the dome rotate around slowly to give the impression of moving clouds.
also put an ATMOSphere node in the background to give nice day/night transitions

monkeycracks · Post by **monkeycracks** » Mon Jul 16, 2007 3:35 pm

I love those skies JP but I bet they use shaders or something.
bitplane, I didn't know you could make skydomes transparent and scale/move them, I'll check that out. Also I'll go ahead and grab the Atmo node thing real fast too.

guess i'll post back here when i'm finished.

monkeycracks · Post by **monkeycracks** » Mon Jul 16, 2007 3:55 pm

Well, I can't get the Atmo node to work because I don't know exactly how the new CustomSceneNode works and I have no use for it otherwise. I'll just make my own day/night transition later.
For now, I just need to get the fog+sky working correctly.

Ico · Post by **Ico** » Mon Jul 16, 2007 6:01 pm

I haven't played Morrowind but other games using the same engine. Think Morrowind is too old for huge shader effects - so I'd guess it just uses 3 or 4 different sky layers - and think the sky is attached to the camera's/player's position so it won't move with the landscape and therefor suggesting a far greater distance.

As for the flying scene those near clouds might be billboards? Hard to tell from that low resolution video. But at least at about 1:50 - 1:54 look behind/below the left (from viewers position) wing - there is a cloud disappearing!?

So even the nicest sky isn't that perfect.

deesine · Post by **deesine** » Tue Jul 17, 2007 3:40 pm

Just thought I'd chip in with some of my experience, though it's not much.

Whenever I've done an animation or a render that needed a backdrop, I've always used spheres, or domes if you prefer, they always look alot nicer than cubes imo, they add a little more depth by being further away on the horizon and gives a better three point perspective feel. So that's a good starting point, a few floating cloud layers could be added below the dome ceiling. Another thing, I tend to squash the dome a bit on the up-axis, it shouldn't be perfectly round.

Anteater · Post by **Anteater** » Tue Jul 17, 2007 5:49 pm

Morrowind is one of my favorite games so I've played it a lot. I'm fairly sure that the sky is shader-based, at least partly.

monkeycracks · Post by **monkeycracks** » Tue Jul 17, 2007 9:22 pm

Must be very very very bad shaders because my computer can run it and I have an anti-shader card.

I'll worry about it later I guess, it'd just be nice to know how to do it.

JRowe47 · Post by **JRowe47** » Tue Jul 17, 2007 10:45 pm

It's done with a skydome. CPU cheap and effective way of getting a good result...

It's not irrlicht specific, but this describes a good method of getting your skydome texture. It wouldn't be hard to piece together some code that created the textures procedurally, based on time of day and some random factor, then blended sequential textures (It would be complex, but not hard

.)

http://www.bajaengine.com/?module=Wiki& ... ky%20Domes

bitplane · Post by **bitplane** » Tue Jul 17, 2007 11:05 pm

wow!

I've gotta get one of those balls!

JP · Post by JP » Wed Jul 18, 2007 8:23 am

Someone on my robotics module at Uni used a ball like that to create 360 degree vision for their robot, twas quite impressive!

bitplane · Post by **bitplane** » Wed Jul 18, 2007 1:39 pm

ordered one, should arrive tomorrow. gonna have some fun with this

GrigoriosSokratis · Post by **GrigoriosSokratis** » Thu Jul 19, 2007 6:20 pm

bitplane wrote:here's an idea-
make a transparent sky dome, scale it up larger than the fog, then move it down so the top is visible. draw a nice cloud cover texture, and have the dome rotate around slowly to give the impression of moving clouds.
also put an ATMOSphere node in the background to give nice day/night transitions

Hi bitplane, I had the same idea. I've tried adding the addSkyDomeSceneNode() skydome with ATMOSphere already running in my virtual world (which btw has an area of 36sq miles) but all I get is a strange effect of sky flickering pixelized sky (that's because the skydome touches the cone I guess)

Also I tried your great clouds Class (here I explained how to make it work in Irrlicht 1.3.1 http://irrlicht.sourceforge.net/phpBB2/ ... 6&start=30 )

The problem is that I don't know how to make the clouds larger using CCloudSceneNode). I've tried changing this part

ParticleData.size = core::dimension2d<f32>(200+f,200+f);

to

ParticleData.size = core::dimension2d<f32>(20000+f,20000+f);

But get a strange result.

Also after a few minutes the clouds just vanish.

I would be great if you could help me with this because your class is just amazing!

BlindSide · Post by **BlindSide** » Fri Jul 20, 2007 1:17 am

monkeycracks wrote:Must be very very very bad shaders because my computer can run it and I have an anti-shader card.

I'll worry about it later I guess, it'd just be nice to know how to do it.

You have a Radeon 9200 that has PS 1.4 and VS 1.1.... Please dont underestimate the power of the mighty Radeon 9200...

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