Hi all,
This question is in relation to skyboxes.

So, all the default skyboxes for GG are DDS files, with the exception of The Forest, which uses JPG files.

I understated that DDS files are designed to be more memory efficient, but the downside is of course a loss of quality.

One of the biggest challenges with designing skyboxes, is to eliminate banding.

When running the same skybox in GG:
a DDS file introduces considerable banding
a JPG file produces a far better result
and a PNG file produces the best result of all.

I have run a few tests, and have not seen any difference in CPU or Memory usage with any of the three file formats. The only difference is a JPG file takes a bit longer to load when first selected in GG settings.

So the question is this:
Since the skyboxes are always displayed, and thus always in memory, does it matter what file format is used?

Thanks for any input.

Use dds format with the RGB8 option to eliminate the banding. This will be the equivalent to .tga and still load into memory well.
Making them at 2048 x 2048 will help a bit also. Higher resolutions are not recommended and if these are for the store will be rejected on size alone.

.jpg are highly compress and contain artifact from compression when zoomed in or scaled making them not the best choice. But the forest skybox looks good as the colors are dark and they blend well.

Most banding can be gotten rid of wit a good blur filter and watching the colors used spreading the gradient ramp out to avoid the banding effect.

Yes the skyboxes are drawn every loop of the game, so the bigger they are the more memory they will use.

@ Pirate Myke, thanks for the quick reply.

I thought that might be the case, just wondered a bit when I came across Forest skybox.

As you mentioned colours and resolution make a big difference.

Currently I dev at 1024, and play with colours, cloud positioning and a myriad of other settings till I get the best balance of atmosphere and the least amount of banding possible, then render at 2048.

I am using the NVidia plugin for Photoshop.
Till now I was outputting using the DXT1 RGB 4bpp - no alpha option.
However it has a Palette RGB 8 bpp - 256 colors option, Should I use that instead?

OldFlak....

I will have to open Photoshop and check the plugin, should be a straight rgb8 option in the when you use no compression.

Pallet color sounds like a banding nightmare to me.

use the 8.8.8 RGB 24 bpp Unsigned option

@ Pirate Myke,
wow thanks for the quick update, I just read your previous post and opened PS to check out the other options, but you beat me to it.

Thanks for all your help.

OldFlak....

@ Pirate Myke, the 8.8.8 RGB 24 bpp Unsigned option works a treat, really appreciate the help there.

Could I ask what the correct formats for terrain files are?

Currently I am using:
For Terrain_D: DXT5 ARGB 8 bpp - interpolated alpha
For Terrain_N: DXT1 RGB 4 bpp - no alpha

These were the formats I believe are correct from what I have read on GG forums, and other google searches.

They seam to work fine in GG, but now I wonder if I have the correct formats here or not as well -

OldFlak....

You are welcome.

DXT5 ARGB 8 bpp - interpolated alpha is correct for the terrain ones. and only the _d files use this.

Do erase the superpallet.ter file and restart gameguru to test terrains.

@Pirate Myke, again thanks for the help,

Sorry to labour the point

So it is correct to use DXT1 RGB 4 bpp - no alpha for the _n files?

OldFlak....