Not a very good subject but let me try to describe what I'm doing. My current process in the Aakrana project is to stress test the A6 rendering engine and so far it's holding up exceptionally well. Using LoD and prebuilt entities I've got a sustained FPS of 40-50 viewing pretty much the entire level up to 10,000 quants. I'm impressed.

Now what I'm looking to do is integrate a fog system for effects to smooth out the clip range but I am having difficulty doing this with the current sky setup. Using a background colour for the map and a skycube the fog works but the sky is visible through the hog to the horizon and just looks gibbled.

What I am trying to achieve is being able to see the Sky above you and say out to maybe 45 or 40 degrees from you but then the fog layers over top of it out to the max clip distance at which point it's jsut the fog and no sky should be visable. This would make a nice clipping effect and clean up the appearance of the world for me a lot. Anyone want to dial me in on this? =)

What I am attempting to achieve (I think) is a single plane sky "ceiling" to my level box that I can add motion and clouds to (Using a layered TGA) and change from blue to black (with stars and planets) as the day progresses. The Skins and time stuff I can workout but getting the fog implementation right is something thats been pestering me for a good week now. (I havent really been focussed on it but I need to get this done now.)

Thank you in advance folks. I hope I was at least a little clear. Ask any questions =)

Mark

I take it from the lack of response that either everyone thinks I'm a raging idjit or there i sno other solution aside from layer volumetric type fog effects and attaching them to the player....

Arrr.... Okee. whatever works. Will tinker with it somemore. I was sure there was an easier way. All I want is for the skybox layer to be under the fog layer. Didnt think it was rocket science =(

Will see what I come up with .

Mark

I've always faked this by painting 'fog' right into the horizon of my skybox image. As long as its the same color as the levels fog, it usually looks pretty seamless. But this may not work depending on what you want to do with your skybox.

Another way would be to use a scene map, a TGA that's solid at the bottom and fades out completely at the top. Have it be on a higher layer than the skybox of course. You'd either make it the same color as your fog, or make it grey and then change its color dynamically to match the fog, which would be the only option if your fog changes color as well.

You can really make some complex skies now days with several layers of all the different sky elements.

Nice technique Ace. Never even thought about that yet. Sounds like it has alot of potential for my application. I've almost got a nice volumetric layer done as well but I'm concerned about the frame rate with those huge models required to do a nice layering effect. My intent was to scale the alpha level of the different "fog" layers based on the current weather state. I could run it at 0 alpha for sunny days and then fog it in to about 50 or 60 alpha for rain and overcast. Obviously this isn't what I'd call a show stopper in my game development, and the weather thing is really just an eye-candy by product of cleaning up the clipping code for a professional looking horizon. Between that scene effect and a customized 3-4 layer model above the player's head I should have the effect I am looking for. Might not be perfect but should be getting close =)

Thanks for the suggestion.

Mark

Using Volumetric fogging technizques I've got a working transparent fog layer. I'm experimenting with a layer way below the player (for hills) and well above the player. (for sky blending with teh Horizon.)

I'm not very good with TGA's but I'll have to test that scenemap thing. Really sounds promising.

Mark

Anyone know what that disk2.mdl from the volumetric demo is? It's got 0 thickness...? I would like to make a doughnut shaped MDL for 3 layers above the player in decreasing sizes and then 2 more smaller disk type mdl's for the top 2 layers. This will allow me to make an excellent blended fog.

Thanks in advance.

Mark

You can use sky dome to simulate some very nice cloud movement without any special techniques (animated tga bla bla).

Make a layer with a normal still, clear sky and then put another layer with the clouds and set their speed_u and speed_v to some value.

The only problem is the fog but if you can paint it on the horizon you could make some very impressive skies. Here's a screenshot of what i've done (but there's the problem of bluring which i hope can be resolved using the fog and that horizon:

http://dimenzije.topcities.com/problem.jpg

PS: copy paste the link to your browser because it doesn't work otherwise.

Judging from the smearing and the edgges I see thats a skycube not a dome isn't it? either way it really looks great. But the smearing is tough to deal with.

I'll play with it some tonight =)

Mark

Ok, I've been working on this on and off for a few days now and I think I've got it figured.. I've got a cone/semi-sphere falgged transparent with an alpha setting and a colour the same as my fog. Think of it as a kind of transparant mini sky-dome inside the skycube. Works well for when the player is in the fog but doesnt blend with the sky at the top where'd I'd like to give the appearance that the fog is thinned.

I am using this effect to hide the smearing and clipping on the skydome and objects at the edge of the clipping range. On a fairwether day the fog colour and semi-sphere color will be light blue. When the weather turns bad the skydome shifts to a greyish colour the fog turns greyish and I want to scale down the semi-sphere entity so that its closer to the player but fade the aplha density on it from the ground to the sky so that the skydome slowly fades into visibility as you scan from teh horizon upwards to 90degrees.

Is there some way to put a skin on the semi-spher emodel with an alpha layer that gradiently turns the transparancy from 100 to zero?

Thanks in advance.

Mark