Moving Terragen Skybox with static land

[DamianTV]

Im a little sick of the purely static skies that dont move or change. I have been able to create my own custom skyboxes using Terragen as described in the various tutorials. Ive had a thought that if I were to render a pic with only the ground and with a black sky, when the pic is imported to a texture, how do I set the black to make it completely invisible, but leave the land? The other half of the sky would be a second skybox around the original with only the sky on it, tiled and scrolling to give just the clouds the appearance of being dynamic. I have a copy of photoshop, but Im not that experienced with either the editor or photoshop 6 and its alpha channels, what can I do to have an effect like that?

[pompey]

easy, just set the poly to portal and translucent the black will disappear.

[DamianTV]

Ok, just tried it, but checking portal makes the entire polygon completely not there, unless I screwed something up in PS... ive included a pic of what its doing just to see if I screwed something up in the alpah channeling... Basicly, Im trying to do an effect like the wall vines in SE where you can see thru the transparent part of the alpha, but I dont know if that will work right inside of a skybox...

[phpPhreak]

change second layer to blend and then set alpha to 100-200 for nice effect, i hope i understand what your trying to do LOL

[DamianTV]

Ok, take a look at this pic, see how the vines and stuff are a completely different texture? (the vines look blurrier than the wall) the vines are not transparent at all, but the alpha channel is making the rest of that particular image completely not there, otherwise we would see vines on a 100% flat black wall. Same thing as the mountain, I want the mountain completely there, no sub-textures, but rendered in Terragen with a flat black sky, and added an alpha channel in Photoshop to make the black sky not come up at all, but it doesnt work. I can (obviously) add the vines and their alpha channel to any texture and make that work, but using similar methods, I cant get the sky to disappear (black sky) to provide a better looking more dynamic sky. See what Im getting at? Im not entirely sure it will work in a skybox tho... I do appreciate the help tho :) D

[pompey]

When rendering the image in terragen on the render diologue box theres 2 tick boxes i think where u can select to render the sky and the land. Uncheck the sky box and it should render with the sky area as black. Just the land! then make this render the texture and do as i said in my first reply!

[Jwh]

Oh, I see what he's getting at. Lemme check what I did in PS.....

alright, 4 pics, 4 posts.

First one: In PS, I made a new picture, 64x64. Here we see the alpha channel(with a black to white gradient):

[Jwh]

Next, I made up a crappy test thing(here would be your actual picture from Terragen, we'll see which parts need to be black and which need to be white in a moment:

(this was saved as a 32-bit .tga)

[Jwh]

Now we make the texture in SS, which you'll have to repeat several times for each portion:

[Jwh]

Finally, for this demonstration of transparency, I made a little room and put a cube inside it. The first texture is the one "underneath"(the original skybox in your case, unless you are putting it into the level itself, in which case it's a translucent/transparent portal like the others said) The new texture is in the second layer and is set to blend. If you're putting it in the level itself, then it goes on the first layer and set those properties, but it's the same deal otherwise.

[DamianTV]

Thanks for all the help guys, that tut on PS actually helped quite a bit, after I got the sky to disappear from the mountains (you'll see why later), I kept running into brickwalls on both. Im working on the dynamic skybox right now, but its not finished, I still need to render about 12 more pics. When Im done with it, Ill put it up for download for evaluation. So far, I have not seen one level done by anyone in the forums, downloaded levels, even by Croteam themselves that has moving clouds and still have the mountains in the backdrop, which is what I was hoping to accomplish, and it looks like I am very close to finishing, so Ill quit blabbing and put this thing together to impress you all!

D

[DamianTV]

Ok, I finished it. Feel free to download it and tell me whether or not it was worth the effort. Click www.intercomm.com/biobob/downloads/SkyBox.zip here for the file or www.intercomm.com/biobob/>here if you just want to take a look before downloading. Its a slightly hefty download for just a skybox, its about 5 megs, but thats because of all the custom textures.

D