How do I lower the horizon line for skyboxes?

[xnasorcerer]

How can I do that? I woud like to have something like this: http://www.planetside.co.uk/gallery/v/tg2gallery/54-new_20sunset_20atmo2_20full.jpg.html , but for skyboxes.

Thanks.

[Oshyan]

Tilt the camera up?

- Oshyan

[xnasorcerer]

Tilt the camera up?

- Oshyan

I tried that, but them the 6 parts of the skybox doesn't fit anymore.

[Oshyan]

Ah yes. Then raise the camera altitude significantly, but keep the camera level.

- Oshyan

[xnasorcerer]

Ah yes. Then raise the camera altitude significantly, but keep the camera level.

- Oshyan

Well, since I am still learning to use terragen, which one of the cameras options is the altitude and what do you mean by keep the camera level?

Also, there is a little bug with the cameras. When I change the position values for a camera, sometimes it also changes the values of another camera that I didn't touch.

Thanks

[Harvey Birdman]

Hi, xna -

Elevation is the 'Y' coordinate - the middle of the three textboxes to the right of the 'Position' label on the camera property page.

The three rotation values below position control camera angle. The first rotates it about the X axis, the second about the Y axis and the third about the Z. The effect, then, is that the first value controls vertical direction (up or down),  the second controls horizontal direction (north, east, south, west), and the third is camera rotation (sideways tilt).

It's the third of these that Oshyan referred to - it should be set to 0 for all frames of a standard skybox.

<edit>
The second should be at zero for all frames except sky and ground.

Ooops! Make that the first, as shown below.      
</edit>

Raise your camera by increasing the Y position coordinate, then shoot your frames with the following rotation settings:

Frame1 - North - 0,0,0
Frame2 - East - 0, 90, 0
Frame3 - South - 0, 180, 0
Frame4 - West - 0, 270, 0
Frame5 - Up - 90, 0, 0
Frame6 - Down -90, 0, 0

As for the bug... are you sure? I've used setups with a half dozen cameras at a time and haven't seen anything like that. Not that it isn't possible, of course...

[xnasorcerer]

Thanks for the explanation.

Well, even increasing the camera elevation, the horizon will always be located at the center of the render window, unless I change the tilt of the camera, which doesn't work for skyboxes.

[Harvey Birdman]

Hmm. It's been a while since I've actually shot one and I don't have the time to experiment at the moment. I assume you've cranked the elevation up to a totally ridiculous value and you're still having the same trouble?

You know, you could just lower the position of your skybox relative to the terrain inside the game environment. (Or raise the terrain relative to the skybox... you get the drift.)

[xnasorcerer]

Hmm. It's been a while since I've actually shot one and I don't have the time to experiment at the moment. I assume you've cranked the elevation up to a totally ridiculous value and you're still having the same trouble?

You know, you could just lower the position of your skybox relative to the terrain inside the game environment. (Or raise the terrain relative to the skybox... you get the drift.)

Yes, but it would be more easy to lower the horizon here inside TG2.

[Harvey Birdman]

That's the way I did it, anyway. I built a variable into the data structure for each terrain module that controlled the skybox height. I found I wanted the programmability.

[JimB]

The only way to do it is like Harvey says, otherwise it's an impossible feat of perspective without being able to offset the camera's projection plane higher (the horizon is the horizon is the horizon). Uncannily though, what Harvey suggests is pretty much making the camera's projection plane higher as a post process. Inside Terragen or outside, you'd be doing the same thing.

[xnasorcerer]

Well, by increasing the camera elevation, inside Terragen or outside, I will making the Sky ceilling much more close and that is not what I want. What I would like to have o inside Terragen is the option to set the terrain under the 0 position and make the sky to render until the terrain position. The horizon it will stay the same, at the same position, but we would achieve the effect of a much more big sky area.

[JimB]

I wasn't talking about putting the camera higher, only its projection plane. It's a very different concept and I'm not sure how best to explain it. Probably a 'filmback offset' is a better way to visualise it. In practice, imagine the camera's view is actually a crop of a much larger picture, centred directly at where the camera is looking. However, that crop can actually be offset in any direction to bring other parts of the picture into view, which means you are not physically moving the camera at all.

I also note that I misunderstood Harvey's post, and it's not the same as a camera offset. Sorry about that.

Try rendering taller horizontal frames, and cropping them in Photoshop or some such?

[EBAndrew]

One thing you could also do is raise the camera up a ton, and fiddle with the height of the cloud layer, and the atmospheres Haze exp/Bluesky exp heights. I know it's more of a workaround than a solution, but...