Development:System Backgrounds

Introduction

This page summarizes concepts and approaches to creating space backgrounds compatible with Vega Strike.

Backgrounds in space are sphere mapped textures arranged in a cube-shaped sky box, so you will need to give us a set of six images.

We could always use more space backgrounds. Ideally, each system in Vega Strike deserves a unique background.

Space Backgrounds

FIXME - need more info on naming, spatial arrangement, and integration

Backgrounds in space are textures arranged in a cube-shaped sky box, like a cardboard paper that you can fold together to a box with the texture remaining on the inside of the box.

Texture Requirements

We require six images that make the six sides of the imaginary box: back, front, right, left, top, and bottom.

The texture graphics format currently recommended for the game is dds format, but the files can be named either png (preferred) or jpg (alternative). This decision will depend on the number of files where the names appear, and your skill and time to find, replace, and test them.

The image ratio horizontal:vertical must be 1:1 (assuming pixel ratio of the map is 1:1), since the texture is mapped to a cube with equal edge dimensions. Necessarily, in order for the surface not to appear distorted, your pixel ratio of the generated texture must be 1.0, i.e. a circle must show as a circle when viewing the texture in an image viewer.

The vertical and horizontal sizes should be a power of two (POT). Really, NPOT (non-power-of-two) textures are really, really, really troublesome. Don't use them. Just use POT. Love the POT. The POT is the mother, the POT is the father. Trust the POT.

That leaves few options:

• 512x512
• 1024x1024
• 2048x2048
• 4096x4096
• 8192x8192

Keeping original high resolution image (e.g. 8192x4096 or 4096x2048) versions in stock helps maintaining quality and scalability as game development progresses or typical screen resolutions rise in the future with better hardware available to the players.

Committed textures are classified as:

• DQ - Development Quality: textures with horizontal resolution of 512 or below and low degree of artistic quality
• RQ - Release Quality: textures with horizontal resolution of 1024 or above and medium degree of artistic quality
• CQ - Cinematographic Quality: textures with horizontal resolution of 2048 or above and high degree of artistic quality

Creating

You can use one of those tools described further down in tutorials. The following descriptions were tested with the settings used by POV-Ray

Tutorials

HDR Shop

[Source: PhpWiki from September 28, 2003 10:49 | Author: Spiner]

Once you have your image done load it into HDRShop and choose Image/Panorama/Panoramic transformations.

Under your source image(left side of menu) there will be a format option(should say mirrorball) choose mirrorball closeup. now on the right side (destination image, keep new image) under format choose Cubic Environment vertical cross.

You should now have a cross with only half the image in it.(saves anything but will call it "image 1")

Now to the second part.

Go to your original image and press "V", that will turn the image 180. Now go to the panorama transformations again. Choose Mirrorball closeup under source image, and cubical map under destination image. Now before you transform the image go to "3D Rotation" and choose arbitrary rotation. and choose settings. Under X axis change it to 180. leave Y and Z 0.

Ok now we have the rest of the cross. save it.(this will be called image 2)

Now go to image/calculate; under image a choose your first image(Image A) and for image b choose the second image (image b); leave c and d alone.

This will calculate the image and put it together to have one seamless image.

Note that this also makes your image double so try to change image b before you transform it.

[2003 | Author: hurleybird]

And another way i found out how to make cube maps is this...

If you have a texture which can be tiled then you can use longitude/latitude to cubic environment (note, you want to add stars AFTER this is done, not before) then you can get some really nice effects.

POV-Ray

POV-Ray (Persistence of Vision Raytracer) is a high-quality, totally free tool for creating stunning three-dimensional graphics. It is available in official versions for Windows, Mac OS/Mac OS X and i86 Linux. The source code is available for those wanting to do their own ports. With its unique scripting approach and through a large base of available texture, pigment, and material functions there are almost unlimited possibilities to creating any kind of graphics.

Maps can be exported by using a spherical camera setting: ...

References

Software, Tools, Tutorials

• Panoramic Image Conversion with HDR Shop