Icons

Icons are small, square images found associated with all items in the game which may be picked up and placed in an inventory - that is, all weapons, armor, clothing, ingredients, tools, gems, stones, keys, books, and scrolls. The image is a "Direct Draw Surface", or DDS file. The alpha channel of the image is used for transparency in the icon.

Requirements

Icons must be a 64pixel x 64pixel DDS file with an alpha channel and no mip maps. Icons are displayed as quite small images by the game, and they must be easily identifiable by the player at that size. They also should make use of transparency to make them appear correctly within the game's user interface. All clothing items must have a male icon image to display properly in a store's inventory.

DXTC Compression Algorithms

DDS files use a compression algorithm called "DXTC". More information on these can be found here. One of the most important aspects of algorithm choice for Oblivion modding is a choice about how the alpha channel of the image is handled by the algorithm.

Icons use the alpha channel for transparency, so at the least the algorithm must have an alpha channel. Often, one of the DXT3 types is used, for the ability to use partial transparency. However, in many cases "DXT1 ARGB 4 bpp | 1 bit alpha" may be preferable. The 1 bit alpha channel means that portions of the image must be either fully opaque or fully transparent, but in many cases this is all that is required for a quality icon. The 1 bit alpha also means that the file size of the image is significantly smaller.

Size and Folder Paths

Icons must go in the Icons folder, or a subfolder within the Icons folder. The Icons folder is found at

... \Oblivion\Data\Textures\Menus\Icons\

It is recommended that custom icons be placed in a folder specific to the mod that they are from, for example:

... \Oblivion\Data\Textures\Menus\Icons\MyMod\Icon.dds

Variations on this may be used, for instance you may wish to keep all of the icons that you make in one place, like so:

... \Oblivion\Data\Textures\Menus\Icons\MyName\ModName\Icon.dds

Or you may have work from several different modders in your mod and you may wish to keep these separate:

... \Oblivion\Data\Textures\Menus\Icons\ModName\ArtistName\Icon.dds

Any number of systems for organizing your files are possible; it is recommended that all modders use some form of organization that works for them and that they stick to it - this will make working with your mods easier for yourself and for users.

The standard icon must be 64x64 - other sizes will not be accepted by the Construction Set.

For middle-range and lower resolution settings, Oblivion will have to resize the icon, which may look bad. However, you may provide resized versions yourself, at 80%, 75%, and 50% the size of the original icon - this may improve the quality of the icon at lower resolutions because image editors are capable of much cleaner resizing than Oblivion is.

These icons must still be 64x64 pixel files - the actual icon image should be resized, not the file. This means there will be a blank border on the right and bottom of the image file, which will be unused by Oblivion.

They also must have the exact same name and have the exact same path as the standard icon, but must be in the menus80, menus75, or menus50 folders, respectively. For example:

... Oblivion\Data\Textures\Menus\Icons\MyMod\Icon.dds <-- full size
... Oblivion\Data\Textures\Menus80\Icons\MyMod\Icon.dds  <-- 80% size
... Oblivion\Data\Textures\Menus75\Icons\MyMod\Icon.dds  <-- 75% size
... Oblivion\Data\Textures\Menus50\Icons\MyMod\Icon.dds  <-- 50% size

Note: Menus75 was added by the later official mods by Bethesda: Vile Lair, Knights of the Nine, and Battlehorn Castle. It was never used by Oblivion or Shivering Isles. It is unclear which, if any, resolutions actually use the 75% size icons.

Note: If an icon is intended to replace a stock Oblivion icon, it is important to supply all four versions of the icon (or at least the 100%, 80%, and 50% sizes) - Bethesda has, and if you do not, you will only replace the full size version, and users who run a lower resolution will see the old icon.

Note: Icons can be created with mipmaps which the game will use for lower resolutions, negating the need to create four versions of an icon. However the CS will throw a non-critical error whenever it encounters an icon with mipmaps.

Stylistic Norms

If you wish to try to match your icons to Oblivion's style, here are some of the standards set by Bethesda:

Icons in Oblivion have a "sketched" quality to them, which is rather noticeable. Users would be able to very easily pick out modded icons that did not do something similar. For seamless integration of items into the game, this should probably be imitated as best as possible.

They also have a soft, yellowish (239 231 173 RGB or #EFE7AD) glow around the image. Note, however, that adding this precludes using a 1 bit alpha channel, which could save significant file space. The glow is not very noticeable, and omitting it is probably worthwhile.

Weapons are typically angled from the top-left corner to the bottom-right, with swords and daggers having their hilt up and left and other weapons having the handle pointing down and to the right. Larger weapons are often cropped in the bottom left, but the top right should be an end of the weapon.

Armor and clothing generally appear as they would looking down on the Ground version of the model. Objects tend to be facing directly at the player or somewhat to the left.

Other objects tend to have a more top-down view in their icon, or simply a more stylistic icon rather than an actual view of the object.