As an example I took the black cow and made it violet.
You can download the final modification here: Download mod
Procedure:
- Start up World Builder
- Since we only want to change a skin, we do not have to load a map.
- Instead, we open the asset browser with F11.
- Create a new project
- Inside the Asset Browser click the bottom left button (Tooltip: Create new project).
- Another window automatically opens. Enter a name for our project (such as cow_violet).
- The new project automatically contains an asset package called content. All modified and new data goes inside this one.
- Our new project is written italic. This means it is not yet running (=active).
- Now we must find the texture inside the em5 project. There are different ways to do this and all of them are a little tricky. I describe just one.
- Open the Prefab Browser and type cow in the searchbar.
- Choose the prefab em5/prefab/animal/cow_black and place it into the map.
- Open the material browser (M key). Blick the bottom left button called Pick. The mouse cursor changes to a hand.
- With the hand cursor click the cow inside your viewport to pick its material.
- Now the material browser displays the cows materials properties in the right table.
- We want to change the color map. Therefore, rightclick ColorMap > Copy Global Asset ID.
- Next we want to use the global asset ID to find our texture in the asset browser.
- In the asset browser select the asset package content in the em5 project (not the one in your project).
- Paste the global asset ID (81654) into the search bar.
- We find 2 textures. The simple name (cow_black_c) is a reference to the photoshop file used by the developers. We can not access this one.
- The RIGHT texture to choose for us is the one with the long cryptic name:
em5/texture/_derived/_material_0_crgb_aa_81654_1_18446744073709551615_1_18446744073709551615_1. - The reason all em5 textures have cryptic names is they were procedurally compressed during development.
- By the way: crgb_aa means the color map is in the channels Red Green and Blue while the alpha is inside the Alpha channel
- Copy the texture to our mod project
- Rightclick em5/texture/_derived/_material_0_crgb_aa_81654_1_18446744073709551615_1_18446744073709551615_1 > Copy to Asset Package > "my mod" > content.
- Now look inside windows explorer under \EM5\data\cow_violet\content\texture\_derived to find the texture.
- Changing the texture
- EMERGENCY 5 textures are .dds-files. To open them with Photoshop you will need NVIDIA Texture Tools for Adobe Photoshop
- I do not explain how to use Photoshop here. There are lots of tutorials on the internet.
- To find out the files format and mipmap settings you can use Windows Texture Viewer.
- In this case we need to save as DXT1 with MipMaps All.
- (Of course you can use Gimp or another program instead of Photoshop)
- Activate, play and export the mod
- After changing the texture, inside the asset browser rightclick your project (not oyur asset package) and turn Running Project on
- The change can directly be seen. Your cow should now be violet.
- To hand your skin to other players rightclick your project again > Publish Mod Project.
- Save a .zip-file.
- Another player needs only drag this file into the modification window inside the launcher to load the map.