Help about creating custom content

[CaptainNemo]

Hello there,

I try to update existant custom content (downloaded here : https://web.archive.org/web/20130630072048/http://www.rctmart.com/downloads/ilgmk/ilgmk-darkride.zip)

However, i only know "RCT2 Object Editor" and this tool is... raw. Update pixel by pixel is not very friendly...
When i see all stuff made by fan, i suppose that images are made on some advanced tools (like Photoshop or other), exported to bitmap, and imported in this famous tool "RCT2 Object editor".

So, have you got a tuto or a list of tools to, for example, export existing sprite of custom object, modify them in any modern tools, and make a new object ?
 

Thanks for your help !