Adding new logos is both pretty easy, in that all you need is a picture file of the correct dimensions = 128 x 128 pixels and pretty hard, in that you can't use a .gif file, it has to be a .dds file (DXT Texture file)
However if you use a program such as 'Paint.Net' (google it if you haven't heard of it before, It's a free graphics editing program) and this program can open, edit and convert most common file formats, including built in support for .dds files.
So in your *:\*****\Sid Meier's Railroad\Assets\Logos folder you should see a bunch of files with that look like this:
train_decal_**.dds
train_decal_**_spec.dds
The ** represent numbers 1 and upwards (I think their is a bout 20 default decals)
Their is also a
train_decal_default_nrml.dds and train_decal_default_spec.dds
These are the default SMR decals, the 'nrml' is the 'normal map' or basic image and the 'spec' is the 'specular map' which basically tells the game how 'shiny' or 'reflective' the decal should be ...
Thee easiest way is to get your image( whatever it is), open it in Paint.Net, highlight (using the magic wand) any part of the image you DON'T want to be seen in SMR (like the white background of my decal for instance, then simply hit 'delete' this gets rid of all the unwanted stuff and you should be left with just your picture surrounded by grey and white squares, now resize the image down to 128 x 128
(if it's not already, you can use the 'canvas size' function to make the image square if its not exactly right).
> It's easier if the image is a multiple of 128 x 128 = 256 x 256 or 512 x 512 or 1024 x 1024 and so on (keep in mind that scaling an image down to 128 x 128 will lose a lot of detail, so try and find a medium sized image to start with around 200 to 300 pixels square)
Now simply use 'save as' in the Paint.Net menu and .dds as the file type and it will aske you for a file name and directory use train_decal_**.dds (where ** is the next number in the sequence AFTER the other decals in the directory then click save ... It will ask you to specify the file save options, which can be a bit confusing, I use the following settings which seem to work fine
Now to create the 'spec' version, the easiest way is to keep the file open in Paint.Net click on 'Adjustments' then 'Black and White' to turn the file into a 'greyscale' version the do the same 'save as' but save THIS file as train_decal_**_spec.dds, making sure you use the same number as the colour version
(For the purists out there, I know this is NOT the ideal way to create a specular map and if your feeling creative you may want to play around with the light and dark areas to create 'metallic' effects or 'shadows' and so on but for a beginner, it's the easiest way to start)
Now when you go to the train table in SMR and use the customisation function, if you have done everything correctly you should be able to scroll through and eventually come to your new logo ...
Good Luck ... and remember to post your creations here (even if you think they aren't very good, it doesn't matter, we may be able to help or offer more advice, or fix a problem you're having) for us all to enjoy