Sky blend effect

[Nir Hasson]

Hi -

I'm using Ogre for almost two months, working on simple game I want to create.
The first thing I did was to create simple scene composed of plane and sky box.
Rendering this simple scene with no special effects results in sharp edges, the ground ends in well defined line and the sky begins from there - not so nice

http://flickcabin.com/public/view/12861

Then I decieded to implement sky blend effect using depth values as blend factor between the scene and the sky box.
The result is much better - to my opinion anyway

http://flickcabin.com/public/view/12860

P.S - I think Ogre is great rendering engine !

[Edit by Kencho]
Changed the links so that they're viewable here. Click on the images for hi-res versions.

[Kencho]

Looking good and useful

[bharling]

Kencho, I cant see the images at all here now!

[xavier]

Ditto, and the links invite me to log in to FlickCabin...

[Kencho]

Restored the links as they were in the original post. There shouldn't be any problem now. It's quite odd though

[Nir Hasson]

Thanks Kencho -

It is strange - but it works now

[tourist]

wow!
thanks a lot!
Great work!

[Kencho]

Thanks Kencho -

It is strange - but it works now

LOL now it isn't working for me. Seems flickcabin has a really odd image hotlinking policy. Consider using imageshack or photobucket in the future

[Ruud v A]

Wouldn't it be better to use blooming? This way things can get transparent and I don't think that's what you want.

[Nir Hasson]

Wouldn't it be better to use blooming? This way things can get transparent and I don't think that's what you want.

Thanks for the suggestion but since blooming is post process effect and it affect the entire scene I didn'nt want to use it. I just wanted to achieve the "merge" effect of the horizon with the sky and I actually implemented it during the scene rendering stage using late sky rendering queue and one ZBuffer render target.
Thanks for the suggestion I'm sure I'll use the compositor system of Ogre in my next steps.

[Kencho]

Blooming? That's a totally different thing. A bloom effect produces a kind of "misted up glass" visualization. This technique deals with removing the far Z clipping issues by gradually blending the far objects with the actual sky/background image.

[sinbad]

Yeah, this is a nice effect, although it adds an extra texture to your terrain materials to do it.

An alternative of course is to use something like Caelum, where the horizon colours are procedural and so you can match up the sky & distant terrain that way. Which one is best depends on your content pipeline.

[Nir Hasson]

Yeah, this is a nice effect, although it adds an extra texture to your terrain materials to do it.

An alternative of course is to use something like Caelum, where the horizon colours are procedural and so you can match up the sky & distant terrain that way. Which one is best depends on your content pipeline.

My first implementation was based on compositors thus it had the overhead of 3 RT - depth, scene, sky. It also caused me some problems with semi transparent objects.
My current implementation uses only one render target and dosen't invovles the compositor system at all.
It is done using the following steps.
1. Render the scene objects to a depth texture - using inheritence and the scheme really make it easy
2. Render the scene as ususal.
3. Render the sky box with ZPass always, alpha blend enabled and use the depth texture values as alpha values of the sky.

So basically execpt of the depth texture there is no other overhead.
I hope to I will find some other usefull stuff I can do with that depth texture.

[oddrose]

looks great! I am a bit curious of how it acts in a more complex scene.

[newbguy]

looks great! I am a bit curious of how it acts in a more complex scene.

+1

[Dastgir]

seam nice effect . Hope yyou make an integration with Caelum