Howto

HOW TOs - art division

Here you can find various art tutorials.

This is a basic tutorial on creating a standard 6 image cubemap from panoramic photograph - be it a sky or environment panorama!

You need:

Part I:

1.) Make a 360° panoramic image (or get it from cgtextures.com). Search the web for info on creating panoramic images.
2.) Open your panoramic image in image editing software (PhotoShop for example) select it with Rectangular Marquee Tool and copy it (Ctrl +C). Then create NEW canvas of appropriate size with transparent background. Paste your panoramic image in it.
3.) GoTo: Image->Canvas Size (or press Ctrl+Alt+C); In Canvas size window tick Relative and in Height text box type a value that is a bit less than the original pixel height of the panoramic image (if image height is 2066px then type 2000px in the box). Press Ok.
4.) Select Move tool (or press V) and move the image to top of the canvas. Make sure that you have Snap enabled (View->Snap)
5.) Select Paint bucket tool, set tolerance to 1, then select a color similar to lower part of the panoramic image (hold Alt + click on the image)
6.) Left click on the empty part of the canvas. Now you should have something like this:
7.) Save the image (Not as JPEG!!!)

Part II:

1.) Run HDRshop v1.0
2.) Open your tweaked panoramic image (made using instructions in Part I)
3.) GoTo: Image->Panorama->Panoramic Transform
4.) In Source image box select Lattitude/Longitude Format; in Destination box select Cubic environment (Vertical cross) Format and 3072 (or any other size, take note that this number has to be 3 x skyshaderSize! For example: 3 x 1024 = 3072 or 3 x 2048 = 6144) width; then press OK
5.) GoTo: Save As-> TGA; save it as YourSkyTextureName_cubemap.tga

Part III:

1.) Open your brand newYourSkyTextureName.tga in PhotoShop
2.) Create rulers on seams - like this: [[1]]
3.) Make sure that the rulers are placed correctly! they should be 1024px (or other skyshader size! eg. 2048px for example) apart from each other!
4.) Select Rectangular Marquee Tool and select, copy and paste on new 1024x1024px canvas each cubemap image (one by one), so that you will get 6 cubemap images. Name them accordingly (_forward, _back, _up, _down, _left, _right). Make double sure that your 6image cubemaps are precisely 1024x1024px big!
5.) Optional - you can save the cubemaps as DDS cubemap file. Save them as nVidias horizontal strip