Creating a skybox from a photo

[Sprony]

Hello there,

This subject has been driving me crazy for the past couple of days. I've found this photo and it's exactly what I want as a skybox.

http://www.hqoboi.com/img/nature/nature ... ma_022.jpg

Since I'm new to this and my knowledge is limited, I started looking for tutorials. Most refer to Terragen but the classic version has a 512*512 size limit and the clouds look like sprites. Also, it does not allow you to import an image you want to convert.

Google then gives you two options. Do it by hand in Photoshop or do it by hand in Photoshop and then render it in a 3D modelling program. I found a extensive tutorial regarding the latter at this site. It's posted in this thread. I've been having trouble with both Photoshop and Maya due to a lack of experience so I wondered, is there another way?

I don't need any fancy stuff or terrain, just a 360 degree sky from that image to be used in Quake 3

Any suggestions, help, links to tutorials, etc would really be appreciated!

[e-freak]

really, it doesn't get much easier from this point than thomas' tutorial (from the other thread http://www.thomashess.net/exchange/tuto ... _skies.pdf) - try to dive into maya or max, the knowledge comes in handy at other times as well

[Sprony]

I'll keep playing with it for sure. I'll post any problems I'll come across.

[Sprony]

The first two bottlenecks:

The tutorial says I should apply a gradient because a sky isn't a single color. In the example it looks like only a small portion has a gradient applied to it. I however, can only add a gradient for the entire file. I don't know if that's a problem.

Tutorial:

Me:

Then the tutorials says:

Merge all layers and fill a new background layer with your color from step 6. [in my case, a bright yellow].

ctrl + click the top layer [the one with transparency] to load it's selection.

Create an alpha channel and fill the selection with white.

According to the tutorial it should look like this:

Except mine looks like this. What am I doing wrong here?

Thanks in advance!

[BaRRaKID]

About the gradient it seems like in the tutorial they used a radial gradient and yours is linear, so you've to change that (i believe that's in the top left corner, there should be a dropdown button there that allows you to change the type of gradient).

The second question, it seems like your image has no transparency? your background is white, so you're basically painting white on white, while on the tutorial the background is transparent.

[Sprony]

Great tips!

I fixed the gradient issue. It now looks like it's supposed to. Still stuck at the alpha channel though. I started over, created a new transparent image [no background] and did all the circles as stated in the tutorial. It only goes wrong when the tutorial says:

Merge all layers and fill a new background layer with your color from step 6.

I tried going to layers - new - background from layer and then select the top layer in my panel. This doesn't work.

Manually adding a new layer doesn't work as well. I guess I'm doing something very simple wrong.

So, if I recap:

I open a 256x256 transparent file in Photoshop

I use the elliptical tool to make a 128px cirkel which I fill with a yellow color using the paintbucket.

I duplicate this layer and apply a gaussian blur of 2px. I duplicate that layer and apply a gaussian blur of 4px and then I duplicate the last layer and apply a gaussian blur of 32px. I merge the blurred cirkels and put that layer under the normal cirkel layer. Then I select the normal cirkel layer and adjust the brightness. I merge the two layers I have and then I'm stuck at filling the background layer [since I don't have one] and creating the alpha channel.

I hope that makes sense :S

[Puddy]

I read this thread as "Creating a skybox from a potato". That is my contribution to this thread.

[knj]

tried this one ?

http://www.3dmotive.com/training/free/c ... ollow=true

[Buddy]

http://www.cgskies.com/resources_tutorial_transform.php

[Sprony]

Thanks for the contribution Puddy! What would we do without you?

No KNJ, I have no knowledge of 3D modelling whatsoever. I bookmarked the page though, because this will come in handy in the future

Buddy, great avatar! Flexifly looks like a dream come true. Except I will have some reading to do. Maybe you know of some tutorials besides the one you listed?

I do want to finish this guide as well, so does anybody know the solution regarding the alpha channel?

[Sprony]

Since I seem to be stuck with the alpha channel and stuff, I decided to give Firefly a try. I read the manual and I've done the following:

I cut up the original image so that there is no grass in it.

I set latitude to 90.

Input mode is equirectangular.

Output mode is cube. I also tried horizontal cross, but the results are the same.

Do I now have to manually fix all the seams in the yellow encircled area? What about the area on the right, that seems very distorted?

I'm sorry if I'm asking simple things but it's all new to me :S