Skybox rendering like Terragen Classic [Angular Distortion?]

[rasteron]

Hi all,

I'm trying to render a set of skybox images using Terragen 2. I was wondering if it is possible to render with the images being rendered in a distorted manner, see image below (is this angular distortion?). Do I need to tweak some camera settings for this effect?

Anyway, I have this kind of setup when I'm using the classic version. Attached is an image (Terragen classic) that I would like to apply when rendering the image.

Also if it is possible to remove Land from rendering (Terrain) just like the classic version?

Any help would be much appreciated.

[Oshyan]

Camera should work basically the same in TG2 as TG Classic, in terms of distortion. In TG Classic it was "Zoom" that determined your field of view. In TG2 it's horizontal or vertical fov, defaulting to horizontal. So increase FoV to get a wider view, it should distort similarly to TG Classic, which is just a result of the camera projection used. I would not say, however, that distortion is *desirable* for a skybox, per se. Also I don't see a lot of distortion in your example image, the edge of the sky is curved because it's a hemisphere over the terrain.

To turn off the terrain in TG2, just go to the settings of the Planet object and uncheck Render Surface. Because the atmosphere is a sphere rather than a hemisphere in TG2, it will render atmosphere all around you, and not a black area like you see in TG Classic.

- Oshyan

[rasteron]

Hi Oshyan,

Thanks for the info, that helped a lot. Ok so it is hemisphere over a terrain, how do I achieve that result? I'm trying to setup the same effect in TG2. The first problem that I'm getting is when I render it on TG2, the sun/sky looks flat when I view it from another angle in my 3D application.

I have some images from a tutorial in setting up a good skybox which works really well in Terragen classic.





Is there an equivalent setting for TG2?

Thanks again.

[Oshyan]

Zoom of 1 is a 90 degree FoV. Perhaps that helps you? Not sure what you mean about the rest, "sun/sky looks flat"...

- Oshyan

[rasteron]

Thanks Oshyan, yes I have set my horizontal fov to 90 and it works. There's a problem with the seams but that's another issue.

Here's a comparison of the two samples from the classic and tg2, they are placed almost at the same location (near the edge) I'm not sure if the clouds around the sun makes it more 3d but as you can see in my image above rendered in tg classic, the sun is rendered distorted which works.

Classic (sun looks 3D)


TG2 (sun looks flat)

[Oshyan]

I can only guess you're just talking about the "glow" around the sun? You can try turning off Visible Disc in the TG2 sun, or increase atmospheric haze density to get more glow.

- Oshyan

[rasteron]

Ok thanks, I will try that.  But how do I get it to render the sun/sky similar to the classic which gives it a spherical (3D) look? Is this possible on TG2?

[Oshyan]

Without knowing the details of your workflow for creating the skybox, I honestly can't say. The usual method for doing this, rendering 6 90 degree FoV images and stitching them together, should give similar results with the defaults in each program.

- Oshyan

[rasteron]

Appreciate your time and help Oshyan.  I'm using pretty much all the defaults but for the important part I have set my camera position to: 5000, 1, 5000 and the hfov to 90. Will that help?

[Oshyan]

I'm sorry, I honestly don't know. This really begins to be more about how the images are dealt with externally, and I don't have direct experience creating skyboxes, so I can't say. There are quite a few threads around here discussing similar needs however (though none have mentioned your particular problem, most often it is about the seams between image tiles, which has a solution as well, using GI caching). Hopefully one of the other threads, or someone who works with skyboxes, can help further. I simply don't understand the problem you're describing, I don't see it in your example images.

- Oshyan

[rasteron]

Ok I will do that. Thanks again for all the help! Good day :-)